Chapter Outline I. The Water-Soluble Vitamins: Eight Bs and a C. *The water-soluble vitamins include the 8 B vitamins and vitamin C.

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1 Chapter 11 Water-Soluble Vitamins Important Math Calculations Calculation of NE = excess protein in g 6 Chapter Outline I. The Water-Soluble Vitamins: Eight Bs and a C. *The water-soluble vitamins include the 8 B vitamins and vitamin C. II. The B Vitamins A. Thiamin. *Thiamin (vitamin B 1 ) functions as the coenzyme thiamin pyrophosphate (TPP) in energy metabolism. 1. Functions of thiamin (Figure 11.3) 2. Dietary recommendations for thiamin 3. Sources of thiamin (Figure 11.5) 4. Thiamin deficiency. *Thiamin deficiency results in the classic disease beriberi. In industrialized countries, thiamin deficiency most often is associated with alcoholism. There is no known danger of toxicity related to high intakes of thiamin. a. Beriberi b. Wernicke-Korsakoff syndrome 5. Thiamin toxicity B. Riboflavin. *Riboflavin (vitamin B 2 ) forms part of the coenzymes FAD and FMN, which function in energy metabolism as hydrogen and electron carriers. 1. Functions of riboflavin 2. Dietary recommendations for riboflavin 3. Sources of riboflavin (Figure 11.8) 4. Riboflavin deficiency. *Ariboflavinosis (riboflavin deficiency) is characterized by inflammation of the mouth and tongue. 5. Riboflavin toxicity C. Niacin. *Niacin (vitamin B 3 ) participates in energy metabolism as part of the coenzymes NAD and NADP. 1. Functions of niacin 2. Dietary recommendations for niacin 3. Sources of niacin (Figure 11.12) 4. Niacin deficiency. *Niacin deficiency results in pellagra, a disease characterized by diarrhea, dermatitis, dementia, and death. 5. Niacin toxicity and medicinal uses of niacin. Niacin supplements containing more than the RDA should be taken only under medical supervision. D. Pantothenic acid. *Pantothenic acid is a part of coenzyme A, a critical player in energy metabolism. 1. Functions of pantothenic acid 2. Dietary recommendations for pantothenic acid 3. Sources of pantothenic acid (Figure 11.16)

2 4. Pantothenic acid deficiency 5. Pantothenic acid toxicity E. Biotin. *The active coenzyme form of biotin is biocytin, which has an important role in many reactions involving energy-yielding nutrients. 1. Functions of biotin 2. Dietary recommendations for biotin 3. Sources of biotin 4. Biotin deficiency. *Biotin deficiency is rare, but may be induced by regularly consuming large quantities of raw egg whites. 5. Biotin toxicity F. Vitamin B 6. *The coenzyme form of vitamin B 6 (pyridoxine) is called pyridoxal phosphate (PLP); it participates in a variety of reactions, primarily involving amino acid metabolism. 1. Functions of vitamin B 6 a. Protein metabolism b. Blood cell synthesis c. Carbohydrate metabolism d. Neurotransmitter synthesis e. Vitamin B 6, Folate, and Heart Disease 2. Dietary recommendations for vitamin B 6 3. Sources of vitamin B 6 (Figure 11.20) 4. Vitamin B 6 deficiency 5. Vitamin B 6 toxicity and medicinal uses of vitamin B 6. *Megadoses of vitamin B 6 can cause permanent nerve damage. G. Folate. *Folate and vitamin B 12 work closely together in a number of metabolic pathways including reactions in cell division and DNA synthesis. 1. Functions of folate 2. Dietary recommendations for folate. *Poor folate status is associated with development of neural tube defects during pregnancy. Therefore, women of childbearing age are advised to take in 400 micrograms of folic acid each day from fortified foods or supplements in addition to other dietary folate. 3. Sources of folate (Figure 11.23) 4. Folate deficiency. *Deficiency of either folate or vitamin B 12 will result in megaloblastic anemia, but vitamin B 12 deficiency (pernicious anemia) also causes irreversible nerve damage. a. Folate and heart disease b. Megaloblastic anemia c. Neural tube defects d. Folate and cancer 5. Folate toxicity H. Vitamin B Functions of vitamin B Absorption of vitamin B 12 (Figure 11.28)

3 3. Dietary recommendations for vitamin B Sources of vitamin B 12 (Figure 11.29) 5. Vitamin B 12 deficiency a. Symptoms of vitamin B 12 deficiency b. Pernicious anemia 6. Vitamin B 12 toxicity Key terms: beriberi, thiamin pyrophosphate (TPP), decarboxylation, glutathione peroxidase, ariboflavinosis, glossitis, stomatitis, cheilosis, seborrheic dermatitis, tryptophan, niacin equivalents (NE), biocytin, carboxylation, biotinidase, avidin, microcytic hypochromic anemia, anemia, dietary folate equivalents (DEF), megaloblasts, megaloblastic anemia, macrocytes, neural tube defect (NTD), spina bifida, anencephaly, myelin sheath, R-protein, atrophic gastritis, pernicious anemia III. Vitamin C. *Vitamin C (ascorbic acid) functions in the synthesis of collagen and other vital compounds, and also works as an antioxidant. A. Functions of vitamin C 1. Collagen synthesis 2. Antioxidant activity 3. Iron absorption 4. Synthesis of vital cell compounds 5. Immune function B. Dietary recommendations for vitamin C C. Sources of vitamin C (Figure 11.31) D. Vitamin C deficiency. *Vitamin C deficiency can cause scurvy, which is characterized by bleeding gums and small hemorrhages on the skin. E. Vitamin C toxicity Key terms: reducing agent, connective tissues, hemochromatosis IV. Choline: Vitamin-Like Compounds. You can synthesize most, but probably not all of the choline you need. V. Conditional Nutrients A. Carnitine B. Inositol C. Taurine D. Lipoic acid E. Bogus vitamins What About Bobbie? Bobbie s intake of five water-soluble vitamins (thiamin, riboflavin, niacin, vitamin B 12, and C) is examined. 1. Would Bobbie benefit from a vitamin/mineral supplement? If so, which one would you recommend and why?

4 2. Which other B vitamin should be examined in Bobbie s diet? Why? Is a vitamin supplement of this B vitamin necessary? Classroom Activities ACTIVITY 1: IDENTIFY THE VITAMIN THAT MATCHES THE DEFICIENCY OR THE TOXICITY The following can be used as a worksheet or as a pre-quiz for the discussion of watersoluble vitamins. Students should match the deficiency or toxicity with the proper vitamin that is responsible for the disease. Answers may be used more than once or not at all. Some questions may have two answers. a. riboflavin e. thiamin i. vitamin B 12 b. niacin f. pantothenic acid c. vitamin C g. biotin d. folate h. vitamin B 6 1. Beriberi is a disease marked by peripheral neurologic, cerebral, and cardiovascular abnormalities. Early deficiency produces fatigue, poor memory, irritation, and sleep disturbances. 2. Ariboflavinosis is characterized by inflammation of the mouth and tongue. 3. Pellagra, is a disease characterized by diarrhea, dermatitis, dementia, and death. 4. Scurvy is characterized by bleeding gums and small hemorrhages on the skin. 5. Deficiency of this vitamin can result in megaloblastic anemia, which is characterized by excess amounts of megaloblasts, large immature red blood cells produced when precursor cells fail to divide normally due to impaired DNA synthesis, in the blood. 6. Excess amounts of this vitamin can cause diarrhea, abdominal cramps, nosebleeds, and nausea. 7. Toxicity of this vitamin can cause flushing of the face, arms, and chest; itching; headaches; rash; nausea; glucose intolerance; and blurred vision. 8. A deficiency of this vitamin can cause irreversible nerve damage. 9. This vitamin does not cure the common cold, but has been speculated to decrease the intensity and duration of the cold. 10. Low intake of this vitamin can result in high homocysteine levels increasing the risk for heart disease. Answers: e; a; b; c; d and o; c; b; o; c; d, i, and h

5 ACTIVITY 2: WHAT DOES TREVOR NEED TO KNOW ABOUT VITAMIN SUPPLEMENTS? This case study can be presented during the lesson on water-soluble vitamins. Students should try to identify the misconceptions Trevor has about vitamin supplements and any other fallacies presented. Case Study As a college student, Trevor is extremely stressed preparing for finals. He s feeling tired and run down, and so decides to buy a vitamin supplement to give him an energy boost. He saw a commercial on television for Vibrant Vitamin that was advertised to boost energy and decrease stress. Trevor goes to a health food store because he knows that is the only place to buy a reliable vitamin supplement. A salesman approaches Trevor and introduces himself as a nutritionist. Trevor now feels much more assured that he will buy a high-quality supplement because a professional is guiding him. Trevor mentions to the nutritionist that he saw an advertisement on the television for Vibrant Vitamin. The nutritionist seems very pleased with Trevor s comments and takes him to the aisle where he sells Vibrant Vitamin. As Trevor goes down the aisle, he notices that most of the vitamins are in the price range from $8 to $35. Trevor hopes that his vitamin choice is in the lower price range as he is on a college student s budget. They come to the vitamin of his choice and he sees that it is $28. The nutritionist states that this is one of the best vitamins because it is all natural and a brand name supplement. He states that if Trevor buys the generic vitamins, he will receive a lower quality product. Trevor looks on the label and notices that the % Daily Value is over 500 percent for vitamin A, vitamin D, folic acid, riboflavin, niacin, and many others. He is now assured that he is getting adequate nutrients for his money. Trevor does ask the nutritionist if the %Daily Value is too high. He states that there is no need to worry about the %Daily Value being too high because any excess vitamins that Trevor consumes will be excreted in his urine. He also emphasizes that it is better to take more vitamins than not enough. Trevor feels confident about the product now that he has evaluated it. He decides to purchase Vibrant Vitamin. Misconceptions 1. Vitamins provide no direct energy (kcalories), but facilitate the metabolism of carbohydrates, fats, and proteins. 2. Emotional stress does not increase the need for vitamins. 3. Health food stores are not the only place to buy vitamin supplements. 4. Just because the salesman introduced himself as a nutritionist, it does not mean that he is an expert or a professional. A nutritionist does not necessarily have an education in nutrition. Registered dietitians complete extensive schooling with a focus in nutrition, an internship, and take a national exam. 5. Cost and brand name does not necessarily indicate the quality of a vitamin supplement.

6 6. Trevor could try a children s vitamin and pay less for the supplement. 7. As a rule of thumb, individuals should buy a supplement that has 150 percent or less of the % Daily Value. 8. Water-soluble vitamins are excreted in the urine, however fat-soluble vitamins are not. 9. More is not necessarily better. Certain vitamins taken in excess can cause toxicity. 10. The body uses synthetic vitamins in the same way it uses natural vitamins. ACTIVITY 3: NAME THAT VITAMIN This activity works well with smaller classes and can make note taking on vitamins more interesting. This game is implemented within the lesson. Students will divide into teams (teams of 5 7 work best). When students hear the word Name within the lesson, they know that the question being asked is worth 10 points. It is a good idea for the instructor to ask a student to keep score. Students can raise their hand to answer the question and the person can discuss the answer with their team for 5 seconds. If the team answers the question right, they get 10 points and if they answer it wrong, they get 10 points. If the first group gets the answer wrong, the question is in play until two more groups answer it. After that, the question is dead. The teams with the most points win. At the discretion of the instructor, a reward for winning can be bonus points, free questions on tests or quizzes, or just simply that the team has won. Instructors should inform students prior to the lesson that the game will be played so that it is an incentive to read the book and understand the material on vitamins. Students should not be allowed to use their book during the game. After each Name question, the instructor can give the notes on that particular question and elaborate on the specific vitamin. This game can be a continuation of Chapter 9, Activity 3. Instructors may want to make more questions multiple choice depending on the difficulty of the class. Questions that can be used in the Name game are the following: NAME: What organ in the body readily removes and excretes excess water-soluble vitamins? ANSWER: kidneys NAME: Name two of the best cooking methods for preserving water-soluble vitamins. ANSWER: steaming, stir-frying, microwaving NAME: What is the name of the thiamin deficiency that was discovered through changing the diets of sailors to include more thiamin rich foods? ANSWER: beriberi NAME: Name one of the richest sources of thiamin in the American diet. ANSWER: pork, wheat germ, enriched breakfast cereals NAME: What vitamin is part of the coenzymes FAD and FMN?

7 ANSWER: riboflavin NAME: Which of the following does thiamin play a role in? a. citric acid cycle b. beta-oxidation pathway c. all of the above ANSWER: c NAME: True or False? Riboflavin is more stable than thiamin and resistant to heat. ANSWER: True NAME: This vitamin plays a key role in oxidation-reduction reactions and can be produced by oxidizing nicotine from tobacco. ANSWER: niacin NAME: Name two of the most common food sources of preformed niacin in the United States. ANSWER: meat, poultry, fish, enriched and whole-grain breads and bread products, and ready-to-eat cereals NAME: What is another name for the niacin deficiency mal de la rosa? ANSWER: pellagra NAME: Name two out of the four Ds related to pellagra. ANSWER: dementia, diarrhea, dermatitis, death NAME: What microorganism was used in identifying that pantothenic acid is needed in the human body? ANSWER: yeast NAME: Pantothenic acid is a precursor to: a. ketone bodies b. vitamin A c. homocysteine ANSWER: a NAME: When proteins are digested a complex is released that contains lysine and which vitamin? ANSWER: biotin NAME: If eaten raw over a long period of time, this food can cause a biotin deficiency. ANSWER: raw eggs NAME: Without an adequate supply of this vitamin, all amino acids become essential. ANSWER: vitamin B 6 NAME: Vitamin B 6, vitamin B 12, and influence homocysteine blood levels. ANSWER: folate NAME: True or False? Megadoses of vitamin B 6 can cause irreversible nerve damage.

8 ANSWER: True NAME: Adequate consumption of this vitamin can help decrease the risk of neural tube defects if taken before and during the early stages of pregnancy. ANSWER: folate NAME: Folate works with what vitamin to perform a number of biochemical functions? A deficiency of either one produces the same abnormalities in red blood cells. ANSWER: vitamin B 12 NAME: Where does most of the folate in the U.S. diet come from? ANSWER: fortified, ready-to-eat cereals and various vegetables NAME: Recent research suggests that folate has an important role in preventing what disease in adults? ANSWER: heart disease NAME: What is the name of the disease that is characterized by excess amounts of megaloblasts in the blood caused by deficiency of folate or vitamin B 12? ANSWER: megaloblastic anemia NAME: For vitamin B 12 to be absorbed in the small intestine, it must bind with what substance produced by the parietal cells of the stomach? ANSWER: intrinsic factor NAME: Vitamin C enhances the absorption of what mineral? ANSWER: iron (nonheme iron) NAME: What is the name of the well-known vitamin C deficiency that is characterized by gum and joint bleeding? ANSWER: scurvy