Sci 241 Week 5

( ©Reinhard/Age Fotostock America, Inc. ) CHAPTER 8 CONCEPTS I I I I I I I I I Thiamin, ribo? avin, niacin, biotin, and pantothenic acid are B vitamins needed to produce ATP from carbohydrate, fat, and protein. Vitamin B6 is important for amino acid metabolism as well as energy production. Folate is a coenzyme that is needed for cell division. Vitamin B12, only found in animal foods, is needed for nerve function and to activate folate. Vitamin C is needed to form connective tissue and acts as a watersoluble antioxidant. Vitamin A is essential for vision, and it regulates cell differentiation and growth. Vitamin D is necessary for bone health. Vitamin E is a fat-soluble antioxidant. Vitamin K is essential for blood clotting. u s t A Ta s t e J Do vitamins give you extra energy? Should everyone take folate supplements? Does eating carrots improve your vision? Can vitamin E protect you from heart disease? The Vitamins Vitamins Are Vital to Your Health Vitamins Provide Many Different Functions in the Body Vitamins Are Found in Almost Everything You Eat We Need Enough but Not Too Much of Each Vitamin Some Vitamins Are Soluble in Water and Others Are Soluble in Fat Many B Vitamins Are Essential for Energy Production Thiamin: Important for Nerve Function Ribo? vin: A Bright Yellow Vitamin Niacin: De? ciency Caused an Epidemic of Mental Illness Biotin: Eggs Contain It but Can Block Its Use Pantothenic Acid: Widely Distributed in Food and Widely Used in the Body Vitamin B6 Is Important for Protein Metabolism Vitamin B6 Is Needed to Synthesize and Break Down Amino Acids Both Animal and Plant Foods Are Good Sources of Vitamin B6 Too Much Vitamin B6 Is Toxic Folate and Vitamin B12 Are Needed for Cell Division Folate: Important for Rapidly Dividing Cells Vitamin B12: Absorption Requires Intrinsic Factor Vitamin C Saved Sailors from Scurvy Vitamin C Is Needed to Maintain Connective Tissue Vitamin C Is a Water-Soluble Antioxidant Citrus Fruit Is One of the Best Sources of Vitamin C Vitamin C Is the Most Common Vitamin Supplement Choline: Is It a Vitamin? Vitamin A Is Needed for Healthy Eyes Vitamin A Comes in Preformed and Precursor Forms Vitamin A Requires Fat for Absorption and Protein for Transport Vitamin A Is Necessary for Vision Vitamin A Regulates Gene Expression -Carotene Is a Vitamin A Precursor and an Antioxidant Vitamin A Needs Can Be Met with Plant and Animal Sources Vitamin A De? iency Is a World Health Problem Preformed Vitamin A Can Be Toxic Vitamin D Can Be Made in the Skin Vitamin D Is Needed to Maintain Normal Calcium Levels Vitamin D De? ciency Causes Weak Bones Only a Few Foods Are Natural Sources of Vitamin D Too Much Vitamin D Causes Calcium to Deposit in the Wrong Tissues Vitamin E Protects Membranes Vitamin E Is a Fat-Soluble Antioxidant Vitamin E De? ciency Damages Membranes Most of the Vitamin E in Our Diets Comes fr om Plant Oils Vitamin E Is Relatively Nontoxic Vitamin K Is Needed for Blood Clotting Vitamin K De? iency Causes Bleeding Drugs That Inhibit Vitamin K Prevent Fatal Blood Clots The Requirement for Vitamin K Is Met by Bacterial Synthesis and Food Sources 8 INTRODUCTION Vitamin D Concerns on the Rise By Karen Collins, R. D. Dec. 5, 2003—A lack of vitamin D—thought to be a problem of a bygone era—is showing up in growing numbers of women, children, and the elderly, increasing the risk of bone disease and possibly other health problems. Exposing only the face, hands, and forearms to sunlight for 10 to 30 minutes, just two or three days a week, can usually produce all the vitamin D we need. Longer exposure doesn’t produce more of this vitamin. Yet today, many people’s lifestyles and locations do not allow them to produce enough, making dietary sources vital. For more information on vitamin D concerns go to www. msnbc. msn. com/id/3660416. A ren’t vitamin de? ciency diseases a thing of the past? After all, the vitamins have been identi? ed, characterized, and puri? ed. We get them from foods that are natural sources and they are added to our breakfast cereal and sold in pill form. For over 100 years scientists have been experimenting with how much of which ones we need to stay healthy and public health of? ials have been providing us with guidelines as to how best to get enough from our diets. How can anyone have a de? ciency? Despite advances in vitamin research over the last century, millions of people around the globe still suffer from vitamin de? ciency diseases. In the United States, the plentiful and 235 236 Chapter 8 The Vitamins varied food s upply make severe vitamin de? ciencies unlikely but this doesn’t mean everyone gets enough of everything all the time. Marginal de? ciencies often go unnoticed and can be mistaken for other conditions. Vitamins Are Vital to Your Health L Vitamins Organic compounds needed * in the diet in small amounts to promote and regulate the chemical reactions and processes needed for growth, reproduction, and the maintenance of health. Vitamins are essential to your health. You only need very small quantities but if you don’t get enough your body cannot function optimally. Severe de? ciencies cause debilitating diseases but even marginal intakes can cause subtle changes that affect your health today and your risk of chronic disease tomorrow. An organic substance is classi? ed as a vitamin if lack of it in the diet causes symptoms that are relieved by adding it back to the diet. The fact that the vitamins we eat in food are essential to health seems simple and obvious, but it was not always so. For centuries, people knew that some diseases could be cured by certain foods. But it was a long time before we understood why particular foods relieved speci? c ailments. Cures attributed to foods seemed like nothing short of a miracle. People too weak to rise from their beds, those with bleeding wounds that would not heal, those too mentally disturbed to function in society, and those with other serious ailments were cured with changes in diet. Even before the chemistry of these substances was unraveled, the civilized world was enchanted with the magic of vitamins. They brought hope that incurable diseases could be remedied by simple dietary additions. Today we understand what vitamins do and why they cure de? ciency diseases, but we still hold out hope for more miracles from these small molecules. And we might get a few. Scientists continue to discover important links between vitamins and the risk of developing illnesses such as heart disease, cancer, osteoporosis, and high blood pressure. What is being uncovered is far subtler than the miracle cures of the 19thcentury de? iency diseases, but people cling to the belief that taking more vitamins will cure what ails them. As a result of this â€Å"more is always better† attitude vitamin toxicities have become a concern. A toxic reaction can be as devastating as a de? ciency. Trying to get the right amount of each of the vitamins may sound analogous to walking a tightr ope between not enough and too much. In reality it is not that hard to get enough of most vitamins from a well-planned diet and most toxicities are not caused by foods but rather by excessive use of supplements. Vitamins provide many different functions in the body To date, 13 substances have been identi? ed as vitamins essential in the diet (Table 8. 1). They were named alphabetically in approximately the order in which they were identi? ed: A, B, C, D, and E. The B vitamins were ? rst thought to be one chemical substance but were later found to be many different substances, so the alphabetical name was broken down by numbers. Vitamins B6 and B12 are the only ones that are still commonly referred to by their numbers. Thiamin, ribo? avin, and niacin were originally referred to as vitamin B1, B2, and B3, respectively, but today they are not typically called by these names. Vitamins each have a unique role in the body. For instance, vitamin A is needed for vision, vitamin K is needed for blood clotting, and vitamin C is needed to synthesize connective tissue. Many body processes require the presence of more than one vitamin. For example the B vitamins thiamin, ribo? avin, niacin, biotin, and pantothenic acid are all needed to produce ATP from carbohydrate, fat, and protein. In some cases adequate amounts of one vitamin depend on the presence of another. For example, vitamin B12 is needed to provide the form of folate needed for cell division and vitamin C helps restore vitamin E to its active form. Vitamins Are Vital to Your Health 237 TABLE 8. 1 Where Does Each Vitamin Fit? Water-Soluble Vitamins B Vitamins †¢ Thiamin (B1) †¢ Ribo? avin (B2) †¢ Niacin (B3) †¢ Biotin †¢ Pantothenic acid †¢ Vitamin B6 †¢ Folate †¢ Vitamin B12 Vitamin C Fat-Soluble Vitamins Vitamin A Vitamin D Vitamin E Vitamin K Vitamins are found in almost everything you eat Almost all foods contain some vitamins (Figure 8. 1). Grain products are good sources of the B vitamins thiamin, niacin, ribo? avin, pantothenic acid, and vitamin B6. Meats, such as beef, pork, and chicken, and ? sh are good sources of all of the B vitamins. Milk provides ribo? avin and vitamins A and D; leafy greens, such as spinach and kale, provide folate, vitamin A, vitamin E, and vitamin K; citrus fruits like oranges and grapefruit provide vitamin C; and vegetable oils, such as corn and saf? ower oil, are high in vitamin E. FIGURE 8. 1 All the food groups contain choices that are good sources of vitamins. ( © Topic Photo Agency) (PhotoDisc, Inc. /Getty Images) Processing affects vitamin content The amount of a vitamin in a food depends on the amount naturally found in that food as well as how the food is cooked, stored, and processed. The vitamins naturally found in foods can be washed away during preparation, destroyed by cooking, or damaged by exposure to light or oxygen. Thus, processing steps such as canning vegetables, re? ning grains, and drying fruits can cause nutrient losses. However, other processing steps such as forti? cation and enrichment add nutrients to foods. Some nutrients are added to foods to prevent vitamin or mineral de? ciencies and promote health in the population (see Chapter 10). For example, milk is forti? ed with vitamin D to promote bone health, and grains are forti? ed with folic acid to reduce the incidence of birth defects. Some foods are also forti? ed with nutrients to help increase product sales. Dietary supplements can boost vitamin intake We also get vitamins in dietary supplements. Currently about half of adult Americans take some form of dietary supplement on a daily basis and 80% take them occasionally. 1 While supplements provide speci? c nutrients, they do not provide all the bene? ts of foods. A pill that meets vitamin needs does not provide the energy, protein, minerals, ? ber, or phytochemicals that would have been supplied by food sources of these vitamins (see Chapter 10). Not all of what you eat can be used by the body The vitamins that we consume in our diets are needed in the cells and ? uids of our body. In order to provide their essential functions, vitamins must get to the target tissues. The amount of a nutrient consumed that can be used by the body is referred to as its bioavailability. Bioavailability is affected by the composition of individual foods, the diet as a whole, and conditions in the body. For example, the thiamin in certain individual foods such as blueberries and red cabbage cannot be used by the body because these foods contain antithiamin factors that destroy the thiamin. An example of how L Forti? cation A term used generally to * describe the addition of nutrients to foods, such as the addition of vitamin D to milk. L Enrichment The addition of speci? c * nutrients to a food to restore those lost in processing to a level equal to or higher than originally present. L Dietary supplement A product * intended for ingestion in the diet that contains one or more of the following: vitamins, minerals, plant-derived substances, amino acids, or concentrates or extracts. L Bioavailability A general term that * refers to how well a nutrient can be absorbed and used by the body. 38 Chapter 8 The Vitamins Chewing helps break apart fiber and release vitamins Bile produced by the liver helps to absorb fat-soluble vitamins Digestion in the stomach releases vitamins from food Some niacin absorption Liver Stomach Digestive enzymes released by pancreas help to further release vitamins Fat-soluble vitamins absorbed from micelles along with dietary fat Pancreas Water-sol uble vitamins (thiamin, riboflavin, niacin, vitamin B6, biotin, pantothenic acid) absorbed by simple diffusion, facilitated diffusion, and active transport Vitamin C absorbed in later portion (ileum) of small intestine Small Intestine Vitamin B12 absorbed in later portion (ileum) of small intestine Large Intestine Absorption of small amounts of vitamin K, biotin, and pantothenic acid made by bacteria in the large intestine FIGURE 8. 2 An overview of vitamins in the digestive tract. diet composition affects vitamin bioavailability is dietary fat and the absorption of fatsoluble vitamins. Because fat-soluble vitamins are absorbed along with dietary fat, diets very low in fat reduce absorption (Figure 8. 2). Conditions in the body affect bioavailability in several ways. Some vitamins require speci? c molecules in order to be absorbed. If these aren’t available, the vitamin cannot be absorbed in suf? cient amounts. For example, vitamin B12 must be bound to a protein produced in the stomach before it can be absorbed in the intestine. If this protein is not available, adequate amounts of vitamin B12 cannot be absorbed. Other vitamins require transport molecules to travel in the blood to the tissues that need them. Vitamin A is stored in the liver, but it must be bound to a speci? transport protein to travel in the blood to other tissues; therefore, the amount delivered to the tissues depends on the availability of the transport protein. We need enough but not too much of each vitamin The right amounts and combinations of vitamins and other nutrients are essential to health. Despite our knowledge of what vitamins do and how much of each we need, we don’t all consume the right amounts. In developing countries, vitamin de? ciencies remain a major public health problem. In industrialized countries, a more varied food supply, along with forti? ation, has almost eliminated vitamin-de? ciency diseases in the majority of the population. Concern in these countries now focuses on meeting the needs of high-risk groups such as children and pregnant women, determining the effects of marginal de? ciencies such as the effect of low B vitamin intake on heart disease risk, and evaluating the risk of consuming large amounts. The RDAs and AIs of the Dietary Reference Intakes (DRI) recommend amounts that provide enough of Vitamins Are Vital to Your Health 239 each of the vitamins to prevent a de? ciency and promote health (see Chapter 2). Because more is not always better when it comes to nutrient intake, the DRIs have also established Tolerable Upper Intake Levels (ULs) as a guide to amounts that are high enough to pose a risk of toxicity (see inside cover). Some vitamins are soluble in water and others are soluble in fat We group vitamins based on their solubility in water or fat, a characteristic that affects how they are absorbed, transported, excreted, and stored in the body. The watersoluble vitamins include the B vitamins and vitamin C. The fat-soluble vitamins include vitamins A, D, E, and K (see Table 8. 1) With he exception of vitamin B12, the water-soluble vitamins are easily excreted from the body in the urine. Because they are not stored to any great extent, supplies of most water-soluble vitamins are rapidly depleted and they must be consumed regularly in the diet. Nevertheless, it takes more than a few days to develop de? ciency symptoms, even when these vitamins are completely eliminated from the diet. Fatsoluble vitamins, on the other hand, are stored in the liver and fatty tissues and cannot be excreted in the urine. In general, because they are stored to a larger extent, it takes longer to develop a de? iency of fat-soluble vitamins when they are no longer provided by the diet. In this chapter the water-soluble vitamins are presented ? rst because many play an important role in the reactions that produce energy from carbohydrate, fat, and protein that have been addressed in Chapters 4 through 7 (Table 8. 2). L Water-soluble vitamins Vitamins that * dissolve in water. L Fat-soluble vitamins Vitamins that * dissolve in fat. TABLE 8. 2 A Quick Guide to the Water-Soluble Vitamins Food Sources Pork, whole and enriched grains, seeds, nuts, legumes Recommended Intake for Adults 1. –1. 2 mg/day Major Functions Coenzyme in glucose metabolism, needed for neurotransmitter synthesis and normal nerve function Coenzyme needed in energy metabolism De? ciency Symptoms Berberi: weakness , apathy, irritability, nerve tingling, poor coordination, paralysis, heart changes In? ammation of mouth and tongue, cracks at corners of the mouth Pellagra: diarrhea, dermatitis on areas exposed to sun, dementia Groups at Risk of De? ciency Alcoholics, those living in poverty Toxicity and UL None reported. No UL Vitamin Thiamin (vitamin B1, thiamin mononitrate) Ribo? vin (vitamin B2) Dairy products, 1. 1–1. 3 mg/day whole and enriched grains, leafy green vegetables, meats Beef, chicken, ? sh, peanuts, legumes, whole and enriched grains. Can be made from tryptophan 14–16 mg NE/day None None reported. No UL Niacin (nicotinamide, nicotinic acid, vitamin B3) Coenzyme needed in energy metabolism and lipid synthesis and breakdown Those consuming a limited diet based on corn, alcoholics Flushing, nausea, rash, tingling extremities. UL is 35 mg from forti? ed foods and supplements (Continued) 240 Chapter 8 The Vitamins TABLE 8. 2 (Continued ) Food Sources Liver, egg yolks, synthesized in the gut Recommended Intake for Adults 30 g/day Major Functions De? ciency Symptoms Groups at Risk of De? ciency Those consuming large amounts of raw egg whites, alcoholics None Toxicity and UL None reported. No UL Vitamin Biotin Coenzyme in Dermatitis, glucose production nausea, and lipid synthesis depression, hallucinations Pantothenic acid (calcium pantothenate) Vitamin B6 (pyridoxine, pyridoxal, pyridoxamine) Meat, legumes, whole grains, widespread in foods Meat, ? sh, poultry, legumes, whole grains, nuts and seeds Leafy green vegetables, legumes, seeds, enriched grains 5 mg/day Coenzyme in Fatigue, rash energy metabolism and lipid synthesis and breakdown Coenzyme in protein metabolism, neurotransmitter and hemoglobin synthesis Coenzyme in DNA synthesis and amino acid metabolism Headache, numbness, tingling, convulsions, nausea, poor growth, anemia Macrocytic anemia, in? ammation of tongue, diarrhea, poor growth, neural tube defects Pernicious anemia, macrocytic anemia, nerve damage Scurvy: poor wound healing, bleeding gums, loose teeth, bone fragility, joint pain, pinpoint hemorrhages Liver dysfunction None reported. No UL Numbness, nerve damage. UL is 100 mg 1. 3–1. 7 mg/day Women, alcoholics Folate (folic acid, folacin, pteroyglutamic acid) 400 g DFE/day Pregnant women, alcoholics Masks B12 de? ciency. UL is 1000 g from forti? ed food and supplements None reported. No UL Animal products 2. 4 g/day Vitamin B12 (cobalamin, cyanocobalamin) Coenzyme in folate metabolism, nerve function Vegans, women, those with stomach or intestinal disease Alcoholics, elderly men Vitamin C (ascorbic acid, ascorbate) Citrus fruit, broccoli, strawberries, greens, peppers 75–90 mg/day Collagen (connective tissue) synthesis; hormone and neurotransmitter synthesis, antioxidant Synthesis of cell membranes and neurotransmitters GI distress, diarrhea. UL is 2000 mg Choline* Egg yolks, organ meats, leafy greens, nuts, body synthesis 425–550 mg/day None Sweating low blood pressure, liver damage. UL is 3500 mg UL, Tolerable Upper Intake Level; NE, niacin equivalent; DFE, dietary folate equivalent. *Choline is technically not a vitamin but recommendations have been made for its intake. Many B Vitamins Are Essential for Energy Production 241 Many B Vitamins Are Essential for Energy Production For many people the term vitamin is synonymous with energy. But vitamins do not actually contain any energy at all. We get energy from the carbohydrate, fat, and protein in our diet, but we can’t use the energy contained in these nutrients without the help of vitamins. The B vitamins thiamin, ribo? avin, niacin, pantothenic acid, and biotin are directly involved in converting the energy in carbohydrate, fat, and protein into ATP—the form of energy that is used to run the body (Figure 8. 3). Each of these vitamins acts as a coenzyme in one or more of the chemical reactions necessary to generate usable energy from these nutrients (Figure 8. 4). Thiamin: important for nerve function Thiamin is needed for nerve cells to obtain energy and to synthesize an important neurotransmitter. A de? ciency of thiamin causes beriberi, a condition that has been known for over 1000 years in East Asian countries. In Sri Lanka, the word beriberi literally means â€Å"I cannot†; this phrase refers to the extreme weakness that is the earliest symptom of the condition. Beriberi came to the attention of Western medicine in colonial Asia in the 19th century. It became such a problem that the Dutch East India Company sent a team of scientists to ? nd its cause. What they were expecting to ? d was a germ like those that caused cholera and rabies. What they found for a long time was nothing. For over 10 years, a young physician named Christian Eijkman worked C C C C C C Although people often take B vitamins to get more energy these vitamins do not actually provide energy. They are however necessary for the body to produce energy from other nutrients. L Coenzymes Small nonprotein o rganic * molecules that act as carriers of electrons or atoms in metabolic reactions and are necessary for the proper functioning of many enzymes. L Beriberi The disease resulting from a * de? iency of thiamin. O C C O C C C C C OH C C Glucose Fatty acid Amino acids Niacin Biotin Niacin Riboflavin Biotin Pantothenic acid Niacin Riboflavin Biotin Pantothenic acid O2 Thiamin Riboflavin Niacin Pantothenic acid C C Thiamin Riboflavin Pantothenic acid C C C Niacin Riboflavin H2O CO2 ATP FIGURE 8. 3 Thiamin, ribo? avin, niacin, biotin, and pantothenic acid are needed in the reactions that produce energy from carbohydrate, fat, and protein. If one of these is missing, energy production is disrupted. 242 Chapter 8 The Vitamins Coenzyme Incomplete enzyme Active enzyme A B A B Enzyme reaction FIGURE 8. 4 The B vitamins serve as coenzymes. This ? gure shows that the coenzyme must bind to form an active enzyme. The enzyme in this example can then join A and B to form a new molecule, shown here as AB. AB to ? nd the cause of beriberi. His success came as a twist of fate. He ran out of food for his experimental chickens and instead of the usual brown rice, he fed them white rice. Shortly thereafter, the chickens came down with beriberi-like symptoms. When he fed them brown rice again, they got well. What did this mean? To Eijkman it provided evidence that the cause of beriberi was not a poison or a microorganism, but rather something missing from the chicken feed. The incidence of beriberi in East Asia increased dramatically the 1800s due to the rising popularity of polished rice. Polished or white rice is produced by polishing off the bran layer of brown rice creating a more uniform product. However, polishing off the bran also removes the vitamin-rich portion of the grain (Figure 8. 5). Therefore, in populations where white rice was the staple of the diet, beriberi, became a common health problem. FIGURE 8. 5 Unenriched white rice is a poor source of thiamin. (Charles D. Winters) L Wernicke-Korsakoff syndrome A form * of thiamin de? ciency associated with alcohol abuse that is characterized by mental confusion, disorientation, loss of memory, and a staggering gait. Thiamin is needed to produce energy from glucose The reason thiamin is needed for nerve cells to obtain energy is because it is a coenzyme for some of the important energy-yielding reactions in the body. One of these is essential for the production of energy from glucose, the energy source for nerve cells. In addition to its role in energy production it is needed for neurotransmitter synthesis and is also essential for the metabolism of other sugars and certain amino acids, and for the synthesis of ribose, a sugar that is part of the structure of RNA (ribonucleic acid). Thiamin de? ciency affects the nervous and cardiovascular systems. Without thiamin, glucose, which is the primary fuel for the brain and nerve cells, cannot be used normally and nerve impulses cannot be transmitted normally. This leads to weakness and depression, which are the ? st symptoms of beriberi; other neurological symptoms include poor coordination, tingling sensations, and paralysis. The reason de? ciency affects the cardiovascular system is not well understood, but symptoms include rapid heartbeat and enlargement of the heart. Overt beriberi is rare in North America today, but a form of thiamin de? ciency called Wernicke-Korsakoff syndrome does occur in alcoholics. People with this condition experience mental confusion, psychosis, memory disturbances, and eventually coma. They are particularly vulnerable because thiamin absorption is decreased due to the effect of alcohol on the gastrointestinal tract. In addition, thiamin intake is low because alcohol contributes calories to the alcoholic’s diet but brings with it almost no nutrients. Many B Vitamins Are Essential for Energy Production RDA Sunflower seeds (1/4 c) Walnuts (1/4 c) Peanuts (1/4 c) Lentils (1 c) Pork (3 oz) Beef (3 oz) Trout (3 oz) Chicken (3 oz) 2% Milk (1 c) Cheddar cheese (1. 5 oz) Orange juice (1 c) Kiwi (2 med) Apple (1 med) Corn (1/2 c) Asparagus (1/2 c) Spinach, raw (1 c) Oatmeal (1 c) Spaghetti (1 c) Brown rice (1 c) White bread (2 sl) Whole-wheat bread (2 sl) 0 0. 2 0. 4 0. 6 0. 8 Thiamin (mg) 1. 0 1. 2 243 FIGURE 8. 6 Thiamin content of selections from each group of the Food Guide Pyramid. The dashed line represents the RDA for adult men. Pork is a better source of thiamin than other meats. (Randy Mayor/Foodpix/PictureArts Corp. ) The recommended intake for thiamin can be met by eating a varied diet You can meet your needs for thiamin by snacking on sun? ower seeds and having a serving of roast pork for dinner. These foods are exceptionally good sources of thiamin. Together 3 ounces of pork and a quarter cup of sun? ower seeds provide 1. 5 mg of thiamin, well above the RDA, which is 1. mg per day for adult men age 19 and older and 1. 1 mg per day for adult women 19 and older. 2 But even a diet that doesn’t include these foods can meet your thiamin needs as long as you make nutritious choices such as those recommended by the Food Guide Pyramid (Figure 8. 6). Legumes, nuts, and seeds are good sources. Grains are also good sources; thiamin is found in the bran of whole grains and i t is added to enriched re? ned grains. A large proportion of the thiamin consumed in the United States comes from enriched grains used in foods such as baked goods. Some breakfast cereals are forti? d with so much additional thiamin that a single bowlful contains more than the RDA. Although it is easy to meet thiamin needs some of the thiamin in foods may be destroyed during cooking or storage because it is sensitive to heat, oxygen, and low-acid conditions. Thiamin availability is also affected by the presence of antithiamin factors that destroy the vitamin. There are enzymes in raw shell? sh and freshwater ? sh that degrade thiamin during food storage and preparation and during passage through the gastrointestinal tract. These enzymes are destroyed by cooking so they are only a concern in foods consumed raw. Other antithiamin factors that are not inactivated by cooking are found in tea, coffee, betel nuts, blueberries, and red cabbage. Habitual consumption of foods containing antithiamin factors increases the risk of thiamin de? ciency. 2 Despite the fact that intakes of thiamin above the RDA have not been shown to be bene? cial, many supplements contain up to 50 mg of thiamin and promise that they will provide â€Å"more energy. † Although thiamin is needed to produce energy, unless it is de? cient, increasing thiamin intake does not increase the ability to produce energy. There is no UL for thiamin since no toxicity has been reported when excess is consumed from either food or supplements. 2 Enriched grains have thiamin as well as ribo? avin, niacin, and iron added to them (see Chapter 4). * Remember 244 Chapter 8 The Vitamins Ribo? avin: a bright yellow vitamin Ribo? avin is a water-soluble vitamin that provides a visible indicator when you consume too much of it. Excess is excreted in your urine—turning it a bright ? uorescent yellow. The color may surprise you but it is harmless. No adverse effects have been reported from high doses of ribo? vin from foods or supplements. FIGURE 8. 7 Milk is packaged in opaque or cloudy containers to protect its ribo? avin from destruction by light. (Charles D. Winters) Milk is the best source of ribo? avin in the North American diet Ever wonder why milk comes in opaque cardboard or cloudy plastic containers? The reason is that it is one of the best sources of ribo? avin in our diet and ribo? avin is destroy ed by light. If your milk was in a clear glass bottle and sat in a lighted grocery store display case for several days much of the ribo? avin would be destroyed. The most ribo? vin-friendly milk containers are opaque so the ribo? avin is fully protected from light (Figure 8. 7). Other major dietary sources of ribo? avin include other dairy products, liver, red meat, poultry, ? sh, whole grains, and enriched breads and cereals. Vegetable sources include asparagus, broccoli, mushrooms, and leafy green vegetables such as spinach. The RDA for ribo? avin for adult men age 19 and older is 1. 3 mg per day and for adult women 19 and older, 1. 1 mg per day. 3 Two cups of milk provide about half the amount of ribo? avin recommended for a typical adult. If you do not include milk in your diet you can meet your ribo? avin needs by including two to three servings of meat and four to ? ve servings of enriched grain products and high-ribo? avin vegetables such as spinach (Figure 8. 8). Ribo? avin is needed to produce energy from carbohydrate, fat, and protein Ribo? avin has two active coenzyme forms that function in producing energy from carbohydrate, fat, and protein. Ribo? avin is also involved directly or indirectly in converting a number of other vitamins, including folate, niacin, vitamin B6, and vitamin K, into their active forms. When ribo? vin is de? cient, injuries heal poorly because new cells cannot grow to replace the damaged ones. Tissues that grow most rapidly, such as the skin and the lin- RDA Sunflower seeds (1/4 c) Walnuts (1/4 c) Peanuts (1/4 c) Lentils (1 c) Pork (3 oz) Beef (3 oz) Trout (3 oz) Chicken (3 oz) 2% Milk (1 c) Cheddar cheese (1. 5 oz) Orange juice (1 c) Kiwi (2 med) Apple (1 med) Corn (1/2 c) Asparagus (1 /2 c) Spinach, raw (1 c) FIGURE 8. 8 Ribo? avin content of selections from each group of the Food Guide Pyramid. The dashed line represents the RDA for adult men. Milk is an exceptionally good source of ribo? avin. Corbis Images) Oatmeal (1 c) Spaghetti (1 c) Brown rice (1 c) White bread (2 sl) Whole-wheat bread (2 sl) 0 0. 4 0. 8 Riboflavin (mg) 1. 2 Many B Vitamins Are Essential for Energy Production 245 ings of the eyes, mouth, and tongue, are the ? rst to be affected. This causes symptoms such as cracking of the lips and at the corners of the mouth; increased sensitivity to light; burning, tearing, and itching of the eyes; and ? aking of the skin around the nose, eyebrows, and earlobes. A de? ciency of ribo? avin rarely occurs alone; it usually occurs in conjunction with de? ciencies of other B vitamins. This is because the same foods provide many of the B vitamins. Because ribo? avin is needed to convert other vitamins into their active forms, some of the symptoms seen with ribo? avin de? ciency re? ect de? ciencies of these other nutrients. Niacin: de? ciency caused an epidemic of mental illness In the early 1900’s psychiatric hospitals in the southeastern United States were ? lled with patients with the niacin-de? ciency disease pellagra. At the time, no one knew what caused it but the prime suspects were toxins or microorganisms. The mystery of pellagra was ? nally unraveled by Dr. Joseph Goldberger, who was sent by the U. S. Public Health Service to investigate the pellagra epidemic. He observed that individuals in institutions such as hospitals, orphanages, and prisons suffered from pellagra, but the staff did not. If pellagra were an infectious disease, both populations would be equally affected. Dr. Goldberger proposed that pellagra was due to a de? ciency in the diet. To test his hypothesis, he added nutritious foods such as fresh meats, milk, and eggs to the diet of children in orphanages. The symptoms of pellagra disappeared, supporting his hypothesis that pellagra is due to a de? ciency of something in the diet. In another experiment he was able to induce pellagra in healthy prison inmates by feeding them an unhealthy diet. The missing dietary component was later identi? ed as the water-soluble B vitamin niacin. L Pellagra The disease resulting from a * de? ciency of niacin. A niacin de? ciency causes dermatitis, diarrhea, and dementia The need for niacin is so widespread in metabolism that a de? ciency causes major changes throughout the body. The early symptoms of pellagra include fatigue, decreased appetite, and indigestion. These are followed by symptoms that can be remembered as the three D’s: dermatitis, diarrhea, dementia. If left untreated, niacin de? ciency results in a fourth D—death. Niacin coenzymes function in glucose metabolism and in reactions that synthesize fatty acids and cholesterol (see Figure 8. 3). There are two forms of niacin: nicotinic acid and nicotinamide. Either form can be used by the body to make the active coenzyme forms. Niacin is found in meats, legumes, and grains Meat and ? sh are good sources of niacin (Figure 8. 9). Other sources include legumes, wheat bran, and peanuts. Niacin added to enriched grains provides much of the usable niacin in the North American diet. Niacin can also be synthesized in the body from the essential amino acid tryptophan. Tryptophan, however, is only used to make niacin if enough is available to ? rst meet the needs of protein synthesis. When the diet is low in tryptophan, it is not used to synthesize niacin. The reason pellagra was prevalent in the South in the early 1900’s is because the local diet among the poor consisted of corn meal, molasses, and fatback or salt pork— all poor sources of both niacin and protein. Corn is low in tryptophan and the niacin found naturally in corn is bound to other molecules and therefore not well absorbed. Molasses contains essentially no protein or niacin and salt pork is almost pure fat, so it does not contain enough protein to both meet protein needs and synthesize niacin. Although corn-based diets such as this one are historically associated with the appearance of niacin de? ciency it has not been a problem in Mexico and Central American countries. One reason may be because the treatment of corn with lime water, as is done during the making of tortillas, enhances the availability of niacin (Figure 8. 10). The diet in these regions also includes legumes, which provide both niacin and a source of tryptophan for the synthesis of niacin. In searching for the cause of pellagra, Dr. Goldberger and his coworkers ingested blood, nasal secretions, feces, and urine from patients with the disease—none of them developed pellagra. This helped to disprove the hypothesis that pellagra was an infectious disease. 246 Chapter 8 The Vitamins RDA Sunflower seeds (1/4 c) Walnuts (1/4 c) Peanuts (1/4 c) Lentils (1 c) Pork (3 oz) Beef (3 oz) Trout (3 oz) Chicken (3 oz) 2% Milk (1 c) Cheddar cheese (1. 5 oz) Orange juice (1 c) Kiwi (2 med) Apple (1 med) Corn (1/2 c) Asparagus (1/2 c) Spinach, raw (1 c) FIGURE 8. 9 Niacin content of selections from each group of the Food Guide Pyramid. The dashed line represents the RDA for adult men. Meat, legumes, and grains are good sources of the vitamin. (PhotoDisc, Inc. /Getty Images) Oatmeal (1 c) Spaghetti (1 c) Brown rice (1 c) White bread (2 sl) Whole-wheat bread (2 sl) 0 2 4 6 8 10 Niacin (mg) 12 14 16 L Niacin equivalents (NEs) The * measure used to express the amount of niacin present in food, including that which can be made from its precursor, tryptophan. One NE is equal to 1 mg of niacin or 60 mg of tryptophan. Today, as a result of the enrichment of grains, including corn meal, with niacin, thiamin, ribo? vin, and iron, pellagra is rare in the United States but it remains common in India and parts of China and Africa. Efforts to eradicate this de? ciency include the development of new varieties of corn that provide more available niacin and more tryptophan than traditional varieties. Because some of the requirement for niacin can be met by the synthesis of niacin from tryptophan, the RDA is expressed as niacin equi valents (NEs). One NE is equal to 1 mg of niacin or 60 mg of tryptophan, the amount needed to make 1 mg of niacin. 3 To estimate the niacin contributed by high-protein foods, protein is considered to be about 1% tryptophan. The RDA for adult men and women of all ages is 16 and 14 mg NE per day, respectively. A medium chicken breast and a cup of steamed asparagus provide this amount. FIGURE 8. 10 Tortillas, eaten in Mexico and other Latin American countries, provide niacin because the corn is treated with lime water, making the niacin available for absorption. (Jeff Greenberg/Photo Researchers) Many B Vitamins Are Essential for Energy Production 247 High-dose niacin supplements can be toxic There is no evidence of any adverse effects from consumption of niacin naturally occurring in foods, but supplements can be toxic. The adverse effects of high intakes of niacin include ? ushing of the skin, a tingling sensation in the hands and feet, a red skin rash, nausea, vomiting, diarrhea, high blood sugar levels, abnormalities in liver function, and blurred vision. The UL for adults is 35 mg, but high-dose supplements of one form of niacin (50 mg or greater) are used under medical supervision to treat elevated blood cholesterol (see Chapter 5). Another form is under investigation for its bene? ts in the prevention and treatment of diabetes. When vitamins are taken in large doses to treat diseases that are not due to vitamin de? iencies, they are really being used as drugs rather than vitamins. Biotin: eggs contain it but can block its use You probably know that you shouldn’t eat raw eggs because they can contain harmful bacteria, but did you know that eating raw eggs could cause a biotin de? ciency? Raw egg whites contain a protein called avidin that tightly binds biotin and prevents its absorption. Biotin was discovered when rats fed protein derived from raw egg whites developed a syndrome of hair loss, dermatitis, and neuromuscular dysfunction. Thoroughly cooking eggs kills bacteria and denatures avidin so that it cannot bind biotin (Figure 8. 1). FIGURE 8. 11 Raw eggs are often used to make high-protein health drinks. This is not recommended because raw eggs may contain bacteria that can make you sick, and egg whites contain a protein that makes biotin unavailable. (Charles D. Winters) Biotin is important in energy production and glucose synthesis Biotin is a coenzyme for a group of enzymes that add an acid group to molecules. It functions in energy production and in glucose synthesis. It is also important in the metabolism of fatty acids and amino acids (see Figure 8. 3). Although biotin de? iency is uncommon, it has been observed in those frequently consuming raw egg whites as well as people with malabsorption or protein-energy malnutrition, those receiving intravenous fe edings lacking biotin, and those taking certain anticonvulsant drugs for long periods. 3 Biotin de? ciency in humans causes nausea, thinning hair, loss of hair color, a red skin rash, depression, lethargy, hallucinations, and tingling of the extremities. Biotin is consumed in the diet and made by bacteria in the gut Good sources of biotin in the diet include cooked eggs, liver, yogurt, and nuts. Fruit and meat are poor sources. Biotin is also synthesized by bacteria in the gastrointestinal tract. Some of this is absorbed into the body and contributes to our biotin needs. An AI of 30 mg per day has been established for adults based on the amount of biotin found in a typical North American diet. High doses of biotin have not resulted in toxicity symptoms; there is no UL for biotin. Pantothenic acid: widely distributed in food and widely used in the body Pantothenic acid, which gets its name from the Greek word pantos (meaning â€Å"from everywhere†), is widely distributed in foods. It is particularly abundant in meat, eggs, whole grains, and legumes. It is found in lesser amounts in milk, vegetables, and fruits. In addition to being â€Å"from everywhere† in the diet, pantothenic acid seems to be needed everywhere in the body. It is part of a key coenzyme needed for the breakdown of carbohydrates, fatty acids, and amino acids as well as the modi? cation of proteins and the synthesis of neurotransmitters, steroid hormones, and hemoglobin. Pantothenic acid is also part of a coenzyme essential for the synthesis of cholesterol and fatty acids (see Figure 8. 3). The wide distribution of pantothenic acid in foods makes de? ciency rare in humans. It may occur as part of a multiple B vitamin de? iency resulting from malnutrition or chronic alcoholism. The AI is 5 mg per day for adults. Pantothenic acid is relatively nontoxic and there are not suf? cient data to establish a UL. 3 248 Chapter 8 The Vitamins Vitamin B6 Is Important in Protein Metabolism Vitamin B6 is one of only two B vitamins that we still know by its number. The ch emical name for vitamin B6 is pyridoxine but we rarely hear it called this. The important role of vitamin B6 in amino acid metabolism distinguishes it from the other B vitamins. Vitamin B6 is needed to synthesize and break down amino acids Vitamin B6 has three forms—pyridoxal, pyridoxine, and pyridoxamine. These can be converted into the active coenzyme form, pyridoxal phosphate, which is needed for the activity of more than 100 enzymes involved in the metabolism of carbohydrate, fat, and protein. It is particularly important in amino acid synthesis and breakdown; without vitamin B6 the non-essential amino acids cannot be made in the body (Figure 8. 12). Pyridoxal phosphate is needed to synthesize hemoglobin, the oxygen-carrying protein in red blood cells, and is important for the immune system because it is needed to form white blood cells. It is also needed for the conversion of tryptophan to niacin, the release of glucose from the carbohydrate storage molecule glycogen, the synthesis of certain neurotransmitters, and the synthesis of the lipids that are part of the myelin coating on nerves, which is essential for normal transmission of nerve signals. Vitamin B6 de? ciency causes numbness and tingling Vitamin B6 de? ciency causes neurological symptoms including numbness and tingling in the hands and feet as well as depression, headaches, confusion, and seizures. These symptoms may be related to the role of vitamin B6 in neurotransmitter synthesis and myelin formation. Anemia also occurs in vitamin B6 de? ciency, because without B6 hemoglobin cannot be synthesized normally. Other de? ciency symptoms such as poor growth, skin lesions, and decreased antibody formation may occur because of the central role vitamin B6 plays in protein and energy metabolism. Since vitamin B6 is needed for amino acid metabolism, the onset of a de? ciency can be hastened by a diet that is low in vitamin B6 but high in protein. H H2N C C O OH Amino acids NH2 C O OH B6 Energy production and glucose synthesis B6 B6 FIGURE 8. 12 Vitamin B6 is essential for many different types of reactions involving amino acids. It is needed to remove the acid group so neurotransmitters can be synthesized, to remove the amino group so what remains can be used to produce energy or synthesize glucose, and to transfer an amino group to make a new amino acid. Neurotransmitter synthesis NH2 Synthesis of nonessential amino acids Vitamin B6 Is Important in Protein Metabolism Folic acid from food and supplements 249 DNA synthesis Active folate Vitamin B12 Inactive folate Methionine High levels in the FIGURE 8. 13 blood increase cardiovascular The accumulation of homocysteine in the blood is associated with an disease risk Homocysteine Vitamin B6 increased risk of heart disease. Vitamins B6, B12, and folate, are needed to keep homocysteine levels in the normal range. Vitamin B6 is needed to break down homocysteine. Vitamin B12 and folate are needed to convert homocysteine to methionine. Vitamin B6 status is related to heart disease risk Vitamin B6 is needed to break down the amino acid homocysteine. If B6 levels are low, homocysteine can’t be broken down and levels rise. Even a mild elevation in blood homocysteine levels has been shown to be a risk factor for heart disease (Figure 8. 13). Two other B vitamins, folate and vitamin B12 are also involved in homocysteine metabolism. These are needed to convert homocysteine to the amino acid methionine. If they are unavailable, homocysteine levels will increase. A study that examined the effect of folate and vitamin B6 intake in women found that those with the highest levels in their diets had about half the risk of coronary heart disease as women wit h the lowest levels. 5 Both animal and plant foods are good sources of vitamin B6 Animal sources of vitamin B6 include chicken, ? sh, pork, and organ meats. Good plant sources include whole wheat products, brown rice, soybeans, sun? ower seeds, and some fruits and vegetables such as bananas, broccoli, and spinach (Figure 8. 14). Re? ned grains, like white rice and white bread, are not good sources of vitamin B6, because the vitamin is lost in re? ning whole grains but is not added back in enrichment. It is added to many forti? ed breakfast cereals; these make an important contribution to vitamin B6 intake. 6 It is destroyed by heat and light, so it can easily be lost in processing. The RDA for vitamin B6 is 1. 3 mg per day for both adult men and women 19 to 50 years of age. A 3-ounce (85-g) serving of chicken, ? sh, or pork, or half a baked potato, provides about one-fourth of the RDA for an average adult; a banana provides about one-third. Too much vitamin B6 is toxic For years people assumed that because water-soluble vitamins were excreted in the urine they could not cause toxic reactions. However, reports in the 1980’s of seve re nerve impairment in individuals taking 2 to 6 g of pyridoxine per day showed these assumptions to be false. 7 The reactions of some supplement users were so severe that they were unable to walk; symptoms improved when the pyridoxine supplements were stopped. The UL for adults is set at 100 mg per day from food and supplements. 3 Despite the potential for toxicity, high-dose supplements of vitamin B6 containing 100 mg per dose (5000% of the Daily Value) are available over the counter, making it easy to obtain a dose that exceeds the UL. These supplements are taken to reduce the symptoms of premenstrual syndrome (PMS), treat carpal tunnel syndrome, and strengthen immune function. Although studies have not found a relationship between carpal tunnel syndrome and vitamin B6 status, some studies report that low-dose supplements of vitamin B6 may reduce symptoms of PMS and improve immune function. Individuals with an inherited disease called homocysteinuria have extremely high levels of homocysteine in their blood and may have heart attacks and strokes by the age of 2. 250 Chapter 8 The Vitamins RDA Sunflower seeds (1/4 c) Walnuts (1/4 c) Peanuts (1/4 c) Lentils (1 c) Pork (3 oz) Beef (3 oz) Trout (3 oz) Chicken (3 oz) 2% Milk (1 c) Cheddar che ese (1. 5 oz) Orange juice (1 c) Kiwi (2 med) Apple (1 med) Corn (1/2 c) Asparagus (1/2 c) Spinach, raw (1 c) Oatmeal (1 c) Spaghetti (1 c) Brown rice (1 c) White bread (2 sl) Whole-wheat bread (2 sl) 0 0. 0. 8 Vitamin B6 (mg) 1. 2 FIGURE 8. 14 Vitamin B6 content of selections from each group of the Food Guide Pyramid. The dashed line represents the RDA for men and women up to 50 years of age. The best sources are meats, legumes, and whole grains. (David Bishop/Foodpix/PictureArts Corp. ) PMS causes mood swings, food cravings, bloating, tension, depression, headaches, acne, breast tenderness, anxiety, temper outbursts, and over 100 other symptoms. Because vitamin B6 is needed for the synthesis of the neurotransmitters serotonin and dopamine, insuf? ient vitamin B6 has been suggested to cause the anxiety, irritability, and depression associated with PMS by reducing levels of these neurotransmitters. Trials on the effect of vitamin B6 supplements on PMS have had con? icting resultsâ⠂¬â€ in some cases low-dose supplements appear to be effective in reducing symptoms. 9 Vitamin B6 supplements have been found to improve immune function in older adults, but the reason for the improvement is unclear. 10 Immune function can be impaired by a de? ciency of any nutrient that hinders cell growth and division. Therefore, one of the most common claims for vitamin supplements in general is that they improve immune function. Vitamin B6 is no exception. Since the elderly frequently have low intakes of vitamin B6, it is unclear whether the bene? cial effects of supplements are due to an improvement in vitamin B6 status or immune system stimulation. Folate and Vitamin B12 Are Needed for Cell Division Inside the nucleus of every cell is the DNA that holds the genetic code. Before a cell can divide it must make a copy of its DNA. The B vitamin folate is needed for the synthesis of DNA and vitamin B12 is needed to keep folate active. Therefore if either B12 or folate is missing, DNA cannot be copied and new cells cannot be made correctly. As a result of this interdependency, many of the same symptoms are seen when either vitamin B12 or folate are de? cient. Folate: important for rapidly dividing cells A number of different forms of folate are needed for the synthesis of DNA and the metabolism of some amino acids. Because folate is needed for cells to replicate, it is particularly important in tissues where cells are dividing rapidly such the bone marrow, where red blood cells are made, and the developing tissues of an unborn baby. Folate and Vitamin B12 Are Needed for Cell Division 251 folate adequate folate deficient Normal cell division Red blood cells Red blood cell precursor FIGURE 8. 15 Cells are unable to divide (megaloblast) Macrocyte Megaloblastic or macrocytic anemia occurs when developing blood cells are unable to divide, leaving large immature red blood cells (megaloblasts) and large mature red blood cells (macrocytes). Folate de? ciency results in anemia One of the most notable symptoms of folate de? ciency is anemia. Without folate, developing red blood cells cannot divide. Instead, they just grow bigger (Figure 8. 15). Fewer mature red cells are produced so the oxygen-carrying capacity of the blood is reduced. This condition is called megaloblastic or macrocytic anemia. Other symptoms of folate de? ciency include poor growth, problems in nerve development and function, diarrhea, and in? ammation of the tongue. Groups most at risk of a folate de? ciency include pregnant women and premature infants because of their rapid rate of cell division and growth; the elderly because of their limited intake of foods high in folate; alcoholics because alcohol inhibits folate absorption; and tobacco smokers because smoke inactivates folate in the cells lining the lungs. Folate intake is related to neural tube defects A low folate intake increases the risk of birth defects that affect the brain and spinal cord called neural tube defects (Figure 8. 16). The exact role of folate in neural tube development is not known, but it is necessary for a critical step called neural tube closure. Neural tube closure occurs ve ry early in pregnancy—only 28 days after conception—when most women may not yet even know they are pregnant. Therefore to reduce the risk of these defects, folate status must be adequate before a pregnancy begins and during the early critical days of pregnancy (see Chapter 12). However, folate is not the only factor contributing to neural tube defects. Not every pregnant woman with low folate levels gives birth to a child with a neural tube defect. Instead, these birth defects are probably due to a combination of factors that are aggravated by low folate levels. Folate status may affect heart disease and cancer risk Low folate intake may increase the risk of heart disease because of its relation to homocysteine levels (see Figure 8. 13). Low folate status may also increase the risk of developing cancer L Megaloblastic or macrocytic anemia * A condition in which there are abnormally large immature and mature red blood cells and a reduction in the total number of red blood cells and the oxygen-carrying capacity of the blood. L Neural tube defects Irregularities in * the formation of the portion of the embryo that develops into the brain and spinal cord. These occur early in development and result in brain and spinal cord abnormalities. Vertebrae Spinal cord Vertebrae Spinal cord FIGURE 8. 16 Early in pregnancy, the neural tube develops into the brain and spinal cord. If folate is inadequate during neural tube closure, neural tube defects such as spina bi? da, shown here, occur more frequently. In spina bi? da the bones that make up the back do not completely surround the spinal cord, allowing membranes, ? uid, and, in severe cases, the nerves of the spinal cord to bulge out where they are unprotected. Normal spine Spine with spina bifida 252 Chapter 8 The Vitamins For more information on folic acid and birth defects, go to the Spina Bifida Association of America at www. sbaa. org of the uterus, cervix, lungs, stomach, esophagus, and colon. Although folate de? iency does not cause cancer, it has been hypothesized that low folate intake enhances an underlying predisposition to cancer. The relation between folate and cancer is strongest for colon cancer. Alcohol consumption greatly increases the cancer risk associated with a low folate diet. 11 L Dietary folate equivalent (DFE) A unit * used to express the amount of folate available to the body that accounts for the higher bioavailability of folic acid in supplements and enriched foods compared to folate found naturally in foods. One DFE is equivalent to 1 g of folate naturally occurring in food, 0. 6 g of synthetic folic acid from forti? d food or supplements consumed with food, or 0. 5 g of synthetic folic acid consumed on an empty stomach. Vegetables, legumes, oranges, and grains are good sources of folate Asparagus, oranges, legumes, liver, and yeast are excellent food sources of folate. Fair sources include grains, corn, snap beans, mustard greens, and broccoli, as well as some nuts. Small amounts are found in meats, cheese, milk, fruits, and other vegetables (Figure 8. 17). Folic acid is added to enriched grain products, including enriched breads, ? ours, corn meal, pasta, grits, and rice. If you look at the label on a bag of enriched ? ur you will see that it is forti? ed with folic acid. Folic acid is a stable form of folate that rarely occurs naturally in food but is used in supplements and forti? ed foods; it is more easily absorbed than natural folate. In the 3-year period after the forti? cation of grain products with folic acid, the incidence of neural tube defects decreased by 25%. 12 Women of childbearing age need extra folate The RDA for folate is set at 400 g dietary folate equivalents (DFEs) per day for adult men and women. Expressing needs in DFEs allows one unit to be used for all the forms of folate; one DFE is equal to 1 g of food folate, 0. g of synthetic folic acid from forti? ed food or supplements consumed with food, or 0. 5 g of synthetic folic acid consumed on an empty stomach. Because supplementing folic acid early in pregnancy has been shown to reduce neural tube defects, a special recommendation is made for women capable of becoming pregnant; 400 g of synthetic folic acid from forti? ed foods and/or supplements is recommended in addition to the food folate consumed in RDA Sunflower seeds (1/4 c) Walnuts (1/4 c) Peanuts (1/4 c) Lentils (1 c) Pork (3 oz) Beef (3 oz) Trout (3 oz) Chicken (3 oz) 2% Milk (1 c) Cheddar cheese (1. oz) Orange juice (1 c) Kiwi (2 med) Apple (1 med) Corn (1/2 c) Asparagus (1/2 c) Spinach, raw (1 c) Oatmeal (1 c) Spaghetti (1 c) Brown rice (1 c) White bread (2 sl) Whole-wheat bread (2 sl) 0 100 200 Folate ( µg DFE) 300 400 FIGURE 8. 17 Folate content of selections from each group of the Food Guide Pyramid. The dashed line represents the RDA for adults. Legumes, forti? ed foods, and some fruits and vegetables are good sources. (George Semple) Folate and Vitamin B12 Are Needed for Cell Division 253 PIECE IT TOGETHER Is It Hard to Meet Folate Recommendations? Marcia would like to have a baby but before she tries to conceive, she wants to be sure she is in the best condition possible. She consults her physician who gives her a clean bill of health but suggests she make sure she is getting enough folate. women who are capable of becoming pregnant should consume 400 g of folic acid from forti? ed foods or supplements each day in addition to the folate found in a varied diet. Folic acid is added to enriched grains, so it can be found in any food that contains enriched grains; you can check the ingredient list to see if the food you have chosen contains added folic acid. The percent Daily Value includes both the natural folate and added folic acid. W HY IS FOLATE A CONCERN FOR WOMEN CAPABLE OF BECOMING PREGNANT ? M Research shows that consuming extra folic acid can reduce the risk of a type of birth defect called a neural tube defect that affects an unborn child’s brain or spinal cord. For the extra folic acid to be bene? cial, it must be consumed for at least a month before conception and continued for a month after. Since many pregnancies are not planned, it is recommended that all women of childbearing age consume 400 g of folic acid from forti? d foods or supplements. Marcia records her food intake for 1 day to determine her folate intake: Food Breakfast Oatmeal, regular Milk Banana Orange juice Coffee Lunch Hamburger Hamburger bun French fries Coke Apple Dinner Chicken Refried beans White rice Tortilla Salad Salad dressing Milk Cake Total Servings 1 cup 1 cup 1 medium 8 ounces 1 cup 1 1 20 pieces 12 ounces 1 medium 3 ounces 1/2 cup 1 cup 1 1 cup 1 Tbsp 1 cup 1 piece Total Folate ( g) 2 12 22 75 0 11 32 24 0 4 4 106 80 60 64 1 12 32 541 g FOLATE INTAKE MEET THE W HICH FOODS IN M ARCIA’ S DIET ARE HIGHEST IN FOLATE ? O F THESE , WHICH DO YOU THINK HAVE BEEN FORTIFIED WITH FOLIC ACID ? M Food Rice Orange juice Your answers: Amount 80 g 75 g Natural Forti? ed W HY IS THE OATMEAL LOW IN FOLATE BUT THE OTHER GRAIN PRODUCTS ARE GOOD FOLATE SOURCES ? M Oatmeal is a whole grain, so it has not been forti? ed with folic acid. The other grain products in her diet, such as the white rice, tortilla, and hamburger bun, are re? ned so they contain added folic acid. Even though Marcia is trying to increase her intake of the folic acid form of this vitamin she should not pass up whole grains—they are good sources of most B vitamins, minerals, and ? er. L IST SOME MODIFICATIONS M ARCIA COULD MAKE IN HER DIET TO PROVIDE THE RECOMMENDED AMOUNTS AND FORMS OF FOLATE ? M Your answer: W OULD YOU RECOMMEND M ARCIA TAKE A FOLATE SUPPLEMENT ? D OES M ARCIA’ S RDA? Your answer: M Yes. Marica consumes 541 g of folate, which is greater than the RDA of 400 g DFE, but her doctor told her that M 254 Chapter 8 The Vitamins Not everyone needs a folate supplement. If you are male or a female who is too young or too old to have a baby, the amount of folate you get from a healthy diet will meet your needs. Even women of childbearing age can get enough folic acid without a supplement if they eat enough folic acid forti? ed foods. a varied diet. The folic acid form is recommended because it is the form that has been shown to reduce birth defects. This recommendation is made for all women of childbearing age because folate is needed very early in a pregnancy—before most women are aware that they are pregnant. To get 400 g of folic acid, you would need to eat 4 to 6 servings of forti? ed grain products each day or take a supplement containing folic acid. Excess folate can mask anemia caused by vitamin B12 de? ciency Although extra folate is recommended for pregnant women, too much is a concern for some groups. There is no known folate toxicity, but a high intake may mask the early symptoms of vitamin B12 de? ciency, allowing it to go untreated so irreversible nerve damage can occur. The UL for adults is set at 1000 g per day of folate from supplements and/or forti? ed foods. This value was determined based on the progression of neurological symptoms seen in patients who are de? cient in vitamin B12 and taking folate supplements. L Pernicious anemia An anemia * resulting from vitamin B de? ciency that 12 Vitamin B12: absorption requires intrinsic factor If you lived in the early 1900’s and developed a condition called pernicious anemia, it was a death sentence. There was no cure. In the 1920’s researchers George Minot and William Murphy pursued their belief that pernicious anemia could be cured by something in the diet. Their experiments were able to restore good health to patients by feeding them about 4 to 8 ounces of slightly cooked liver at every meal. Today we know that liver contains high levels of vitamin B12. We also know that pernicious anemia is not actually caused by a lack of the vitamin in the diet, but rather an inability to absorb the vitamin. Vitamin B12 absorption requires a protein called intrinsic factor that is produced by cells in the stomach lining. With the help of stomach acid, intrinsic factor binds to vitamin B12 and this vitamin B12-intrinsic factor complex is then absorbed in the small intestine. When very large amounts of the vitamin are consumed, some can be absorbed without intrinsic factor. This is why Minot and Murphy were able to cure pernicious anemia with extremely high dietary doses of the vitamin. Today, pernicious anemia is treated with injections of vitamin B12 rather than plates full of liver. occurs due to a lack of a protein called intrinsic factor needed to absorb dietary vitamin B12. L Intrinsic factor A protein produced * in the stomach that is needed for the absorption of adequate amounts of vitamin B12. L Cobalamin The chemical term for * vitamin B . 12 Vitamin B12 is needed for nerve function Vitamin B12, also known as cobalamin, is necessary for the maintenance of myelin, which is the coating that insulates nerves and is essential for nerve transmission. Vitamin B12 is also needed for the production of energy from certain fatty acids and to convert homocysteine to methionine (see Figure 8. 13). This reaction also converts folate from an inactive form to a form that functions in DNA synthesis. Because of the need for vitamin B12 in folate metabolism, a de? ciency can cause a secondary folate de? ciency and, consequently, macrocytic anemia. Symptoms of vitamin B12 de? ciency include an increase in blood homocysteine levels and anemia that is indistinguishable from that seen in folate de? ciency. Other symptoms include numbness and tingling, bnormalities in gait, memory loss, and disorientation due to degeneration of the myelin that coats the nerves, spinal cord, and brain. If not treated, this eventually causes paralysis and death. Consuming extra folate can mask a vitamin B12 de? ciency When the diet is de? cient in vitamin B12, consuming extra folate can mask the vitamin B12 de? ciency by preventing the appearance of anemia. If the d e? ciency is not treated, the other symptoms of B12 de? ciency, such as nerve damage, progress and can be irreversible. This connection between folate and vitamin B12 has raised concerns that our folate-forti? d food supply may allow B12 de? ciencies to go unnoticed. So far, this

Are Violent Video Games Bad for the Youth

In recent discussions of violent video games, a controversial issue has been whether violent video games are bad for youth or not. On one hand, some argue that video games do not affect the youth at all. On the other hand, however, others argue that violent video games affect the youth tremendously. According to media violence researcher Craig Anderson, Chair of Iowa State University’s Department of Psychology, â€Å"in a violent video game, you rehearse the entire aggression sequence from beginning to end† (Hoerrner & Hoerrner 2). According to [his] view, he is saying that â€Å"you have to be vigilant, looking for enemies, looking for potential threats; you have to decide how to deal with the threat, what weapon to use, and how to use it; and then you take physical action to behave aggressively within the game† (Hoerrner & Hoerrner 4). The issue is whether violent video games are bad for eight, nine, or even ten year olds. My own view is that violent video games are indeed bad for young children. Though I concede that whether a child’s parents choose to allow their children to play these violent games is up to them, I still maintain my view that violent games are bad. A perfect example reassuring a parent that their child is not participating in playing these violent games is to check the ratings on the video games to make sure there is no violence in them. Although it might be objected that parents do not have time to check the ratings on their kid’s games, I reply that it is, once again, an option guaranteeing their children are not being exposed to violence. All in all, the issue is important because these violent video games are affecting children’s behavior, making them more aggressive, as well as more violent. Allowing kids to play violent video games changes the way they act towards their peers by causing them to become more aggressive. They no longer seem to have compassion towards one another, but instead coldness towards each other. This was proven when the American Psychological Association concluded that â€Å"playing a lot of violent video games is related to having more aggressive thoughts, feelings, and behaviors. Furthermore, playing violent games is also related to children being less willing to be caring and helpful toward their peers† (Junior Scholastic 1). Therefore, when children experience more aggression, they are going to feel that their aggressive manner is fine. This age group is not going to take a second look at their negative actions since they see it as â€Å"just fun and games† (Junior Scholastic 1). In essence, by allowing kids to play what they want and not setting boundaries for the kids, parents are not doing any justice to their offspring; instead, parents are saying that it is alright to treat others in an aggressive manner as long as it is just in fun and games. Another perfect example of how violent video games cause children to become more aggressive towards their peers would be the afterschool program I work for — LA’s Best. There I see how these games affect the kids due to how they act towards each other. They are always play-fighting with each other and having fun in their eyes, that is, until someone comes to me or my other staff members crying. When we ask them why they were play-fighting to begin with, they all have the same similar respond-‘that’s how they fight in Mortal Kombat. ’ Mortal Kombat is a popular series of fighting games that contain high levels of blood and gore. So to see our kids reenact what they see on their video games is upsetting because it shows us, the staff, that our kids version of playing together is hitting and tumbling around with each other until someone gets hurt. The eight to ten year olds no longer see playing together as participating in a friendly game of soccer, but instead, a vicious way to kick those who they despise. Therefore, by allowing our kids to involve themselves in these vicious games, changes their definition of the meaning of ‘fun’. They now see fun as hitting and kicking each other until someone is down in pain since they see this type of act of violence in their video game. Lastly, not only do kids experience aggressive behavior through video games, but also criminal violent behavior. This is due to the high rating of violence in the kid’s games. These games make it seem okay to shoot and kill people because the young children can always restart the game and play again. However, in reality, the only thing that these games do for children is actively train them to kill. Take for instance, Retired Lt. Col. Dave Grossman who â€Å"argues that children learn to use weapons and become sharp shooters through simulated games the same way soldiers use simulations to improve their shooting precision. Just as children can improve their phonics with Learn to Read with Winnie the Pooh, they can learn to shoot with deadly accuracy, playing Doom, Splinter Cell, Hitman, and other first-person shooter games† (Hoerrner & Hoerrner 2). Although many would question what Grossman is saying, it actually was proven to be accurate â€Å"in [the] 1997's high school shootings [in] Paducah, Kentucky, [when] the 14-year-old who opened fire on a before school prayer group landed eight out of eight shots on eight different targets. Five of those were headshots† (Hoerrner & Hoerrner 2). Keep in mind the â€Å"teenage shooter had never held a real gun before his shooting rampage†¦ however, spent long hours playing first-person shooter games that simulated killing with the same weapon he used that morning† (Hoerrner & Hoerrner 2). To sum it up, the violence in video games does lead to violent behavior. Video game interaction leads kids to think that using violence is acceptable, causing them to choose their fist over rationality. In conclusion, violent games do indeed lead to aggressive and violent behavior. Not only do these games cause children to be aggressive towards one another, but they also lead to the physical pain of others due to the high content of violence. This is due to children having the entire aggression sequence from beginning to end imprinted in their mind. This therefore, leads them having to seek potential threats while having to figure out which physical action will have the best outcome. This is why every parent should watch the levels of violence in video games as well as set boundaries to what their children can and cannot play.

Do You Know a Child that Does Not Want to Ride a Bike? Essay

Do you know a child that does not want to ride a bike? Well I do not know anyone. This means I was a healthy young girl like others who were willing to learn how to ride the bicycle. I remember that process so I think I was around five years old. Therefore, to learn riding a bike on my own without the training wheels was an exciting experience. At that moment I did not think about bicycle accidents at all and consequences. Finally, when you learn how to ride the bike it lasts forever and that why is so important to do it at childhood age. I was very excited when my parents bought me a bike. This meant that it was about time for me to learn riding a bike on my own. I could not wait until my dad put all the bike pieces together. I remember how I sat on the bike and got so scared â€Å"how am I going to learn to ride my bike?†. My dad made me calm down when he told me that he is going to hold the bike and I will be fine. Although, I still was scared but I trusted my dad and started pressing the pedals. Everything was going well so I was getting more excited and fascinated. However, I forgot about my dad holding the bike all the time. After while my dad let go the bike and I fell of course I cry and got enough for one day. Finally, I realize that it is going to be difficult and challenging to lear rinding the bike. However, I still thought that riding a bike is so much fun but it will take a lot of practice. The next day in the morning I was ready to do it again of course with help of my dad. For this reason, I suffered my dad from the morning. Finally, he agreed to help me. This time I was riding the bike much more stable and faster so my dad was running and got tired quickly since he did not want me to fall again. Therefore, our lesson did not last long but I felt confident after and for the next day I was ready to try it all by myself. Hence, the next day my precious learning was going smoothly. Finally, by looking forward and pedaling I was riding the bike on my own for the first time. This day bring me so much happiness and new experience. Riding the bike it is so much fun but sometimes accidents happen and they hurt so much. I also, remember my accident and how all that happened. I thought that I am excellent bicycle rider already and I rode the bike so fast. Until my mom saw me, she shout right away â€Å"slow down† for this reason, I braked to hard. Thus, at this moment my body jumped out of the bikes steering wheel to the front. I landed on the ground additionally I did not move at all. My mom was speechless and in her mind thought flashed â€Å"is she is dead†. I know that because she told me later. She finally came over to get me and find out if I am fine. After the accident I had a couple bruises but nothing broken. This was my first big accident but I learn that I should not ride so fast and be careful more when I am on the bike. Riding the bicycle is very important because it is good exercise and so much for when the whole family is able to ride their own bike. However, we must remember that the easiest way is to learn at young age. While we are children we are forget all the bruises so quickly. Moreover, children are not so scared and do not give up so easily. Sometimes even if the children do not want to do it again it is so much easier to convince them with good a example or advice. Children will listen faster than adults and will try again. These are all the reason why I am thankful to my parents that I know how to ride the bike as a child. Since I learned how to ride the bike as a child I did transfer to my children. Me and my family draw benefits by riding a bike during the summer. That why is important to learn the bike specially when we are young. In conclusion, learning riding the bicycle is important specially at young age. Furthermore, it is a big and thrilling experience which one bring happiness for rest of the life. Bicycle accidents just teach as a lesson how to ride more safely. Therefore, all the parents should help their children learn riding a bike so afterwards they will be grateful to them for knowing how to ride the bike.

ASSESSMENT 2 Assignment Example | Topics and Well Written Essays - 3500 words

ASSESSMENT 2 - Assignment Example Another important aspect that is worth mentioning in the paper is the fact that there was a limited period of time that the company gave when it comes to the claiming of the funds by the owners of the money used in the business operation. This was therefore the means that the company employed to enable it to realize exorbitant sales and so is the profit. It is quite normal that the aim of every business entity is to make profits and so all businesses will do all he possible actions just to enable them reach this aim. During the liquidation, the firm therefore found out it a bit challenging since there was the need for the payment of the moneys that were taken from the mother company, Fone4U to the new subsidiary company Telephony Limited. This is the case that the company is now facing. It therefore calls for the necessity of giving some pieces of advice to the various stakeholders who were involved on this kind of business transactions on he various measures that they can take to sa ve the situation (Alex, 2012). On giving advice to the customers, it is important to highlight that the customers need to take various actions to enable them to get the 60% of the finances that they are entitled to claim from the company. For any transaction that involves parties, it is always very clear to have a written document as proof that kind of show that there was an agreement that was made by the parties. This therefore binds the company with the other parties who are affected in one way or the other based on the actions that the company has taken. Considering this, it is important to note that the customers therefore were in some form of binding agreement with the company that they were to claim the money in limits of three days and because this was quite short for certain customers to make it there, some had to let the money stay and continue with the business operation (Matt, 2011). This was the core factor that made the business to make

David L. Miller Case Study Example | Topics and Well Written Essays - 250 words

David L. Miller - Case Study Example His characteristics made him difficult to detect because of hypocrisy and deceit in presenting himself. Miller is an innovate fraudster and extensive used various elements of opportunity triangle to steal funds. First, he committed fraud before concealing his record through falsification of records. Notably, he used to concealment techniques of rationalization, opportunity, and motive to commit fraud. Different pressures motivated Miller to embezzle such as the need to buy a car and pay for mortgages. He, therefore, rationalized his actions by starting a family and providing for them as a cover-up ploy.The framing of the T-shirt indicates Miller’s obsession with material possessions as a means of proving his integrity. This compels him to engage in fraud. One of the red flags that could have tipped off company includes Miller’s flashy lifestyle and expensive taste. Companies hesitate to prosecute white-collar criminals because it is expensive for the organization. Howev er, the consequence of not prosecuting such persons entails tainting of the company's image. Law enforcement officials, thus, should encourage more prosecution through in-depth investigating and put fraud deterrence mechanisms. Victimized companies had the opportunity to sue Miller and demand for compensation for their losses.

Is Theseus an example of a typical ancient Greek hero Essay

Is Theseus an example of a typical ancient Greek hero - Essay Example The story follows the same motifs that are followed by other hero stories. These motifs include the background of the hero, the heroic tasks accomplished by the hero, his love life and his downfall due to his own mistakes. Similar to several other Greek hero stories, the story of Theseus even focuses on the background of the heroes. Lord Raglan has provided events that occur in the lives of a Greek hero and some of these events relate to the background regarding the birth of the hero. Raglan states that a Greek hero is mostly born to a royal mother and his father is either mortal or an immortal person (Dowden 104). The father of a hero in most cases is either a God or a King. In Theseus case, he was actually born to a king named Aegeus but was brought up by a king named Pittheus who was also his grandfather (Grant 14). Raglan even states that just before or just right after the birth of a Greek hero, the child is tried to be killed by his own father or even by his own grandfather. In the story of Theseus, he was not tried to be killed by any of his relatives at birth. Raglan even noted that most of the Greek heroes are brought up by either one of the parents or by parents who are not related to him by blood. In case of Theseus, he was brought up by her mother, but he even had his grandfather as a father image and is not brought up by foster parents. Furthermore Raglan argues that when the Greek hero grows up or reaches the life stage of manhood, he is informed about his actual father and later sets out to claim the kingdom he is going to control in future (Dowden 104). In case of Theseus, his mother later informs him that his father is a King and guides him to perform a task that will prove to the king that Theseus is his son. He completes the task which is to lift a stone and obtain the sandal and sword of his father and sets out on a journey to meet his father and live under his father’s Kingdom. Another important element of a heroic story

Citizen Kane and Deat of a Salesman Essay Example | Topics and Well Written Essays - 500 words

Citizen Kane and Deat of a Salesman - Essay Example bears his greatest source of frustration since, despite his looking forward to his elder brother’s prosperity, he ends up a poor man, demoted and stopped from working. His entire life has little depictions of achieving what he ever wanted. On the contrast, Charles seem very prosperous in his life. He is a prominent icon in the journalism department as he makes the deeming decisions at yellow journalism. His prosperity is well defined in his prominent relationship with the president where he ends up vying for the New York state governor seat along with his marriage to the president’s daughter, Emily. When compared to Willy, Charles seems to have anything he needs at his possession. He has a great family; a wife and a son with immense prosperity depicted in the kind of career he lead. We learn that Willy had always wanted to be like his prosperous diamond oriented brother only for him to work for long years with an ultimate termination on his work life. He ends up living on the basis of childhood fantasies of which he never came into a consensus with ideas of his maturity. Apparently, both icons in the two films end up as failures especially in the mannerisms through which they handled relationships. Charles ends up a lonely man, with two divorced wives; Emily and Susan. He does very little to maintain a good relationship both to his family and to himself. It gets to a point that he shuns people from entering his mansion where he only interacted with his workers. It is clear that Charles fails in maintaining healthy relationships though on the other hand Willy succeeds a bit in maintaining his family but dies an unsatisfied man. Unlike Willy, Charles may have experienced a dead end in the kind of relationships he had, but it seems like he has always wanted a life for himself. He is unhappy on losing everything with reference to his nature where he has always wanted everything for himself. Life looses meaning to him to the point that he dies a happy man. He

Discuss the impact on British Society of the cultural revolution of Essay

Discuss the impact on British Society of the cultural revolution of the 1960s - Essay Example When social historians refer to "The Sixties", it is rare that they are talking about the decade in its entirety or that decade exclusively. For example, some claim that the sixties began, as a cultural phenomenon, in 1963. A convincing case can be made in support of this. Events such as the assassination of President Kennedy, Martin Luther Kings "Dream Speech", the debut albums of both The Beatles and Bob Dylan immediately appear as cultural turning points. 1963 appears to be the point at which civil rights, counter/youth culture and a new, somewhat alien mentality began to emerge into the mainstream consciousness. In spite of this, Marwick has argued that it is impossible to view the phenomenon in a "hermetically sealed" time frame, and that it truly began in the late fifties, and came to its conclusion in the early seventies. This is compatible with the idea that 1963 was important, indeed Marwick suggests it marks the beginning of the "High Sixties", but we must also acknowledge the gathering momentum of change in the years leading up to this point. Thus, the period of the Long Sixties I will be discussing here refers to 1958-1974. A far more difficult definition comes with the terms "cultural" and "revolution". To further complicate matters, when the two are used together, we can turn them into a proper noun, as with Mao Zedongs Cultural Revolution. Thus, it is important for us to differentiate between that Cultural Revolution, and Cultural Revolution in the far broader terms we are describing here. Was this a collective movement towards a universalistic revolution, or were individuals campaigning for their own singular interests? So what is a revolution, and, perhaps more pertinently, what is a culture? Revolution is a term which appears with startling regularity in world history, and has been applied to many different things. In this case, revolution refers to a paradigm shift

Assignment 1 Essay Example | Topics and Well Written Essays - 500 words - 3

Assignment 1 - Essay Example Once the exercise commences, nurses or practitioners will utilize electronic feedback tool to monitor the patients’ condition at prescribed intervals. Mainly, monitoring and comparison will be against the already known and earlier data regarding VAP prevalence. This is after 48 hours of intubation among the ICU patients (Fineout-Overholt & Johnston, 2007). Comparing VAPB’s effectiveness with the already attained and recent data is due to the method’s risk. Since, both the caretakers and even nurses will be reluctant in allowing certain patient to experience VAP’s adverse effects while claiming it is an experimentation exercise. Besides, the participants while in this condition entail quick medical intervention to regain their stability, hence they cannot afford to act as a control group (Fineout-Overholt & Johnston, 2007). Variables will encompass varied intervals intentionally ascertained by the nurses or practitioners meant to record the patients’ progress. The intervals’ recording inception will be after intubation; earlier than the anticipated time, which numerous studies normally contend ICU patients start to experience VAP (O’Keefe-McCarthy, Santiago & Lau, 2008). Since, the core purpose in this exercise will encompass comparing nurses’ recordings and the recent data whose collection was in the absence of VAPB (O’Keefe-McCarthy, Santiago & Lau, 2008). This is to ascertain its effectiveness, which both the nurses and practitioners ought to advocate in their practice to shun VAP adverse effects. These encompass augmenting mortality rates, severe pain experienced by the ICU patients and high costs involved in alleviating VAP (O’Keefe-McCarthy, Santiago & Lau, 2008). Since the exercise’s participants involve ICU patients who may be unable to make informed verdicts by themselves, the nurses will have to seek consent from their relatives or their caregivers (O’Keefe-McCarthy, Santiago & Lau, 2008). This is especially when it is

African Americans and the Prison System Essay Example for Free

African Americans and the Prison System Essay I. Introduction In the book the Mugging of Black America, Earl Ofari Hutchinson relays an interesting experience by a reporter. The reporter, who spent two and a half hours watching suspects march before Washington, D. C. Superior Court Judge Morton Berg, noted that all but one of these subjects was Black. He stated, ? Â §There is an odd air about the swift afternoon? Xan atmosphere like that of British Africa in colonial times? Xas the procession of tattered, troubled, scowling, poor blacks plead guilty or not guilty to charges of drug possession, drug distribution, assault, armed robbery, theft, breaking in, fraud and arson. According to Hutchinson, the reporter witnessed more than a courtroom scene; he witnessed the legacy of slavery. This paper will attempt expand on Hutchinson? Â ¦s theory. It will do so by first describing slavery and its lasting impact then it will attempt to show how the current criminal justice system mirrors slavery. PART 1: Slavery I. The History of Oppression and African Americans The history of the oppression as it relates to African Americans began in 1619. It was this year in which a Dutch ship brought the first slaves from Africa to North America. Following this arrival of twenty Africans in Virginia, white European-Americans created the institution of slavery. Slavery spread so quickly that by 1860 the original twenty slaves turned into nearly four million. In the beginning the legal status of these Africans was undefined. This absent definition created a lack of certainty which allowed for some slaves to become free after years of service. This only lasted briefly. In the 1660s, however, the colonies began enacting laws that defined and regulated slaves and the institution of slavery. One of the most important of these was the provision that black slaves, and the children of slave women, would serve for life. These ? Â §breeding laws were just the beginning. Soon, slavery in the United States was governed by a body of laws developed from the 1660s to the 1860s. Even though every slave state had its own slave code and case law, it became universal that slavery was a permanent condition. In addition to slavery being a permanent condition, slaves were also, under these laws, considered property. Slaves, being property, could not own property or be a party to a contract. Since marriage is a form of a contract, slave marriages had no legal standing. Most codes also had sections regulating free blacks. Under these codes blacks who were not slaves were still subject to controls on their movements and employment. These laws served not only as a physical limitation, but an ideological one also. In addition to granting slave owners and white people power over slaves and in some cases free blacks, the laws also granted slaveholders and white-Europeans an intangible source of power. Socially, the institution of slavery allowed white slave owners to believe they had not only physical control, but physical and mental superiority over the slaves. With only a few exceptions, all slaves were Africans. This fact placed the label of inferiority on black skin. The actual institution of slavery as it relates to master and slave lasted up in till the Civil war. The American Civil War was fought, in part, over slavery. During the war, President Abraham Lincoln issued the Emancipation Proclamation, which ? Â §freed all slaves. This seemingly, brought the end of slavery throughout the United States, but unfortunately left a lasting impression. From this point on slavery took on a new form as former slaves being associated with the label of inferiority. II. The lasting effects of slavery: continuous oppression Slavery is defined by Webster? Â ¦s dictionary as ? Â §The state of being under the control of another person . Aalthough the actual physical control and violence supposedly ended after the emancipation proclamation, The intangible theory of supremacy derived from the institution of slavery resulted in many lasting effects. These effects in and of themselves are a form of force, a form slavery. a. The lost sense of culture and cultural pride: Feeling of inferiority Slave drivers made great efforts to eliminate African culture. For instance Africans were beaten if they were caught speaking their native languages or carrying out native rituals . Therefore, they were not able to effectively pass the languages, stories and traditions on to their children. This forced suppression resulted in the loss of verbal records and a rich legacy of history. It is no secret that there is pride in culture. Taking away the culture takes away the pride and the motivation and results in feelings of worthlessness. b. no economic foundation Slave drivers not only attempted to deprive the Africans of there culture and pride, but they successfully robbed them economically. Slaves were forced to work without pay for years while padding the pockets of the slave owners. This deficit of economics resulted in an inability to establish an economic foundation in the United States. c. Unleveled playing field Along with the deprivation of financial resources, another significant factor concerning the state of African Americans is arrested development. Slaves were deprived of opportunities to learn and become more competitive in many areas of society. Black people were not allowed to read or learn to read, so they could not take advantage of written text. All these lasting effects placed blacks in a severely disadvantaged state when slavery was abolished, led a socioeconomic structure in which white people generally held the highest ranks and Black people generally held the lowest ranks. III. Maintaining oppression In order to maintain this socioeconomic structure, there always seems to be a new form of oppression set in place to maintain ? Â §slavery. As if the above detrimental effects of slavery were not enough, the White southerners were anxious to maintain more direct power and control over people with black skin, despite there classification as ? Â §free. The White southerners decided to, again, use the law in order crystallize there theory of inferiority and keep black people at the lowest ranks. In 1865, southerners created Black Codes, which served as a way to control and inhibit the freedom of ex-slaves. These historic Codes controlled almost all aspects of life, and prohibited African Americans from almost all the freedoms that had been won during the Civil War. The codes, which were blatantly racist and oppressive, were eventually suspended in June 1866, during the ? Â §reconstruction era. During this time period in America and despite resistance, African-Americans were slowly becoming part of this nations inclusion. By 1868, the 14th Amendment to the Constitution confirmed the long awaited citizenship for Blacks in America. By 1870, the 15th Amendment was added to the Constitution which made it illegal to deny the right to vote based on race. The Reconstruction era, although short-lived, showed the first real attempts of inclusive freedom for African-Americans since the abolition of slavery. Gains were taking place: Citizenship, Voting, Education, and Politics. But, the underlying desire to have power over those in black skin never subsided. Just like the black Codes, this desire to dominate again manifested itself in another form, Jim Crow Laws. These laws promoted discrimination and the denial of equal protection by law. Just like the codes, they too were eventually abolished. Just like the Codes, Jim Crow laws, the desire of our society to suppress those in black skin will soon take another form. Today that form is the Criminal Justice System. PART 2 The New Age Slavery: The Prison System I. The Prison Institution Prisons are big in the United States. During the past 20 years, the United States experienced a massive increase in incarceration. The prison population increased fourfold, from 330,000 in 1980 to nearly 1. 4 million in 1999, and the incarceration rate increased from about 140 to about 476 per 100,000 resident populations. Today there are more than two million Americans behind bars. But even more startling is the fact that more than one-half of these incarcerated Americans have black skin. Although black Americans only make up about 12% of the US population, they account for more then 30% of all arrests, 44% of all prisoners and 40% of prisoners on death row. II. Race and the Prison System These obvious disparities in the criminal justice system can be attributed to many different things ranging from racial profiling to the lack of opportunity and poor education, but most criminal justice observers believe that these disparities have emerged from the underlying assumptions rooted in slavery. The assumption that slaves were inferior has carried over to today. Currently this theory of inferiority and desire to maintain oppression influences one of the major policies in place attacking African Americans today, the ? Â §war on drugs. Most of the shocking disparities in the criminal Justice System as it relates to African Americans in prison can be attributed to the ? Â §war on drugs. According to a study by Human Rights Watch, African-Americans comprise 62 percent of the drug offenders admitted to state prisons. In seven states, blacks constitute between 80 and 90 percent of all people sent to prison on drug charges. According to studies of the U. S. Commission on Civil Rights, African-Americans constitute 15 percent of the national drug users, but comprise an amazing one-third of all those arrested on drug charges and 57 percent of those convicted on drug charges. The criminal justice system generally, and contemporary crime and drug policies in particular, serve as a means for White America to control the African Americans like they did in the 1600 . III. The lasting oppression Similarly to the black codes and segregation implemented after the abolition of slavery; restrictions are placed on prisoners after they are released. Once a prisoner is released from prison, parole and the bans on public assistance, public housing restrictions, etc. create barriers and a seemingly doomed cycle of dominance. Since half of the prisoners in prison are African American, these barriers, like the lasting effects of slavery, have a disproportionate effect on our black communities. III. The effects of oppression According to the Department of Justice? Â ¦s Bureau of Justice statistics, the number of adults in prison, jail, or on probation or parole reached almost 7 million during 2004. Since Blacks comprise 30 percent of probationers and 41 percent of prisoners. That means around 4,500,000 African Americans are affected directly by the criminal justice system. Unfortunately those African Americans sent to prison or under parole are not the only people affected. The impact on the black community does not stop at the prison door, conversely it goes far beyond. Even after a prisoner is released there are lasting effects to the prisoner, his or her family and the community as a whole. a. Demise of the Black family One effect of the high rate of incarceration of African American males in particular has been the decreasing number of marriageable men in the African American community. Along with high rates of homicide, AIDS-related deaths and other factors, this has created a substantial imbalance in the male-female ratio among adult African Americans. Whereas gender ratios for African Americans at birth are about 102-103 males for every 100 females, by the age range 40-44, this declines to 86 males per 100 females, whereas white rates are 100:100 for this group. b. Lost political voice The impact of the criminal justice system on the black community goes beyond the declining family structure to issues of political influence as well. As a result of laws that disenfranchise felons and ex-felons in various states, an estimated 1. 4 million African American males, or 13% of the black male adult population, is either currently or permanently disenfranchised as a result of a felony conviction. In fourteen states, a felony conviction can result in lifetime disenfranchisement, and in seven of these states, an estimated one in four black males is permanently disenfranchised. Thus, not only are criminal justice policies contributing to the disproportionate incarceration of African Americans, but imprisonment itself then reduces the collective political ability of African Americans to influence these policies. V. Solutions The constant demise in the structure of the black family, lost political influence and seemingly arrested development are all very familiar results of a history of oppression. Since these effects of slavery and disparities in the criminal justice system seemingly steam from hundreds of years ago there is no quick fix. Ideally the answer would lie in the destruction of all prejudice. But, it is impossible to erase the deep seated legacy and resurfacing effects of slavery. Therefore this problem must be attacked from a variety of different angles. Recommendations for change can be considered in the areas of awareness, legislative change, criminal justice officials? Â ¦ initiatives, and criminal justice/community partnerships. The following are some suggested that will allow for a beginning to a seemingly circular and endless problem. 1. Legislative Actions Legislation should be pushed to Reconsider Mandatory Sentencing Policies and Equalize Penalties for Crack and Powder Cocaine . 2. Criminal Justice Officials? Â ¦ Initiatives ?n Criminal Justice Officials should Expand Drug Policy Options And Expand the Use of Alternative Sentencing 3. Criminal Justice/Community Partnerships. The criminal Justice system and the community should attempt to Increase Community-based Diversion from the Criminal Justice System And Strengthen the Link between Communities and the Justice System VI. Closing Oppression in the form of institutionalization is nothing new to those dressed in black skin; it has been present since 1619. In this year Africans were brought to the United States and forced into the institution of slavery. Even after the abolition of slavery, a series of codes and segregation laws were set in place to maintain the suppression of black people because black skin was stigmatized as inferior. Even though the prejudice and biased codes and laws were eventually abolished themselves, this stigma remains. Because this theory of black inferiority was embedded in the American culture due to slavery, various means of oppression are able to continually resurface in different forms. Today that form is Criminal Justice System, more specifically the drug policies. Practically mirroring the institution of slavery, African Americans are being controlled and dominated by this system. Control by the USCJS includes the probation, parole, imprisonment, lost economic power, struggling communities and lost political voice. In order to end this vicious cycle of oppression, action must be taken. First people must be made aware of the disparities. Next those who are made aware must press for legislative change, criminal justice officials? Â ¦ initiatives, and criminal justice/community partnerships. The challenge for the community at large is to engage in broad discussion of the mix of family, community, and government initiatives that can begin to reverse the cycle that has been set in motion in recent years. Let? Â ¦s do what Abraham attempted o do in 1877, let? Â ¦s end this legacy of slavery.