The Vitamins

1. The Vitamins

2. Vitamins • Organic, essential nutrients required in minute amounts to perform specific functions that promote growth, reproduction, or the maintenance of health and life

3. Bioavailability The availability of vitamins from food depends on two factors: • The quantity provided from a food • The bioavailability of the vitamin from that food Bioavailability refers to the rate and extent to which a nutrient is absorbed.

4. Vitamins As Precursors Or Provitamins • Some vitamins occur in foods in inactive forms. • Once in the body they are changed chemically to an active form of the vitamin.

5. Solubility • Apparent in the different food sources of the vitamins • Affects their absorption, transport, and excretion by the body

6. Water Soluble Thiamin- B1 Riboflavin- B2 Niacin- B3 Biotin Pantothenic Acid Vitamin B6 Folate Vitamin B12 Vitamin C Fat Soluble Vitamin A Vitamin D Vitamin E Vitamin K Water Soluble Versus Fat Soluble Vitamins

7. Water Fat Soluble Soluble

8. Thiamin- B1 • Part of coenzyme thiamin pyrophosphate (TPP) which assists in energy metabolism • Recommended intake is 1.2 mg/day and 1.1mg/day for adult men and women, respectively. • Best sources of thiamine are pork, liver, sunflower seeds, legumes, whole grain and enriched breads and cereals.

9. Thiamine Deficiency • Prolonged deficiency is known as Beriberi. • First recognized in East Asia where rice comprises ~80% of their diet. They began “polishing” the rice which is removal of the hull. Rice hulls were the principal source of thiamine. • Characterized by edema (wet beriberi) or wasting (dry beriberi), enlarged heart, muscle weakness, loss of appetite, mental confusion, paralysis.

10. Thiamine Toxicity • None noted • Cannot occur from food sources • May occur with supplementation, however excess is readily excreted in the urine

11. Riboflavin- B2 • Part of coenzyme flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) used in energy metabolism • Supports normal vision and skin health • Recommended intake is 1.3 mg/day and 1.1 mg/day for adult men and women, respectively. • Best food sources are milk, yogurt, cottage cheese, meat, whole grain and enriched breads and cereals.

12. Riboflavin Deficiency • Deficiency of riboflavin is referred to as ariboflavinosis. • Characterized by angular cheilosis, glossitis, photophobia, and inflamed, scaly skin lesions

13. Riboflavin Toxicity • None noted • Cannot occur from food sources • May occur with supplementation, however excess is readily excreted in the urine

14. Niacin- B3 • Part of the coenzyme nicotinamide adenine dinucleotide (NAD) used in energy metabolism • Supports the health of skin, nervous system, and digestive system • Recommended intake is 16 mg NE/day and 14 mg NE/day for adult men and women, respectively. • Best food sources are milk, eggs, meat, poultry, fish, whole grain and enriched breads and cereals.

15. Niacin Deficiency • Deficiency of niacin is known as Pellegra. • Characterized by vomiting, diarrhea, glossitis, fatigue, memory loss, bilateral symmetrical dermatitis.

16. Niacin Toxicity • “Niacin flush”- a burning, tingling, itching sensation that occurs when a person takes large doses of nicotinic acid. • Can effectively lower blood cholesterol but such therapy needs close monitoring because of its adverse side effects. • Common toxicity symptoms include nausea, diarrhea, vomiting, peptic ulcers, headache, fatigue, low blood pressure, and liver damage.

17. Biotin • Functions as a coenzyme in the metabolism of carbohydrates and fats • Biotin is needed in very small amounts. Instead of an RDA, an Adequate Intake (AI) has been established at 30 μg/day for both adult men and women. • Biotin is widespread in foods, however, the best sources are organ meats, soybeans, fish, and whole grains.

18. Biotin Deficiency • Deficiency is uncommon. • Symptoms include loss of appetite, nausea, depression, lethargy, hallucinations, muscle pain, weakness, fatigue, dry scaly dermatitis, and hair loss.

19. Pantothenic Acid • Involved in more than 100 different steps in the synthesis of lipids, neurotransmitters, steroid hormones, and hemoglobin • The principal active form is part of coenzyme A called “CoA”. • CoA is involved in several metabolic pathways.

20. Pantothenic Acid {continued} • An AI for pantothenic acid has been set at 5mg/day to replace daily losses. • Pantothenic acid is widespread in foods, however the best sources are organ meats, mushrooms, broccoli, and whole grains.

21. Pantothenic Acid Deficiency • Deficiency is uncommon. • Characterized by nausea, vomiting, stomach cramps, insomnia, fatigue, and depression

22. Vitamin B6- Pyroxidine • Part of coenzymes important in amino acid and fatty acid metabolism • Helps convert tryptophan to niacin and serotonin • Helps make red blood cells

23. Vitamin B6- Pyroxidine {continued} • Recommended intake is 1.3 mg/day for both adult men and women. • Best food sources are green leafy vegetables, meats, fish, poultry, shellfish, and legumes.

24. Vitamin B6- Pyroxidine Deficiency • Deficiency is uncommon. • Characterized by small cell type anemia, glossitis, angular cheilosis, insomnia, irritability, muscle twitching, convulsions, scaly dermatitis, and kidney stones.

25. Vitamin B6- Pyroxidine Toxicity • Toxicity is uncommon. • First appeared in 1983 in people taking greater than two grams per day for two months or more

26. Folate • Functions as coenzyme used in DNA synthesis and therefore is important in cell formation • Folate prevents neural tube defects in the growing fetus. The brain and spinal cord develop from the neural tube in the early weeks of gestation. • Neural tube defect- malformations of the brain, spinal cord or both during embryonic development.

27. Folate {continued} • Recommended intake is 400 μg/day for both adult men and women. • Best food sources are green leafy vegetables, legumes, seeds, and liver. • There is growing evidence that folate plays a role in preventing heart disease by decreasing homo-cysteine levels. Elevated homocysteine is associated with increased risk of developing heart disease.

28. Folate Deficiency • Characterized by a large cell type of anemia, heartburn, diarrhea or constipation, immune system suppression, glossitis, mental confusion, weakness, fatigue, irritability, and insomnia.

29. Vitamin B12 • Characterized by the presence of cobalt • The active forms of coenzyme B12 are methylcobalamin and deoxyadenosyl-cobalamin. • Works closely with folate, thus also playing a role in the prevention of heart disease

30. Vitamin B12 {continued} • Recommended intake is 2.4 μg/day for both adult men and women. • Only found in animal products • Best food sources are meat, fish, poultry, shellfish, milk, cheese, and eggs.

31. Vitamin B12 Deficiency • B12 gets absorbed by attaching to a glygoprotein in the stomach known as the intrinsic factor (IF). • Pernicious anemia is due to lack of or ineffective IF. • It is characterized by a large cell type anemia and memory loss. • A deficiency can also occur from inadequate dietary intake.

32. Vitamin C • collagen synthesis • antioxidant properties • thyroxin synthesis • amino acid metabolism • immune system booster • aides in the absorption of iron

33. Vitamin C {continued} • Recommended intakes are 60 mg/day for both adult men and women, 100 mg/day for pregnant women and smokers. • Best food sources are citrus fruits, dark green vegetables, cantaloupe, strawberries, peppers, and tomatoes.

34. Vitamin C Deficiency • Referred to as Scurvy. • Characterized by small cell type anemia, pinpoint hemorrhages, immune system suppression, bleeding gums, loose teeth, muscle pain, joint pain, and poor wound healing.

35. Vitamin C Toxicity • Cannot occur from food sources • May occur with supplementation, however, excess is readily excreted in the urine • Characterized by nausea, diarrhea, abdominal cramps, headache, fatigue, and rashes

36. Vitamin A • Three active forms in the body: retinol, retinal, and retinoic acid, collectively known as the retinoids. • Promotes vision • Participates in protein synthesis and cell differentiation

37. Vitamin A {continued} • Supports reproduction and growth • Recommended intake is 1000 μg and 800 μg retinol equivalents (RE) per day for adult men and women, respectively. • Best food sources of preformed vitamin A are foods of animal origin such as liver, fish, milk and milk products, butter, and eggs.

38. Vitamin A Deficiency • Deficiency takes one to two years to develop after vitamin A intake has been stopped due to the body’s effective storage of fat soluble vitamins. • Characterized at first by night blindness, but if left untreated can cause xeropthalmia or keratomalacia • Xeropthalmia- progressive blindness caused by vitamin A deficiency.

39. Vitamin A Deficiency • Keratomalacia- softening of the cornea seen in severe vitamin A deficiency that leads to irreversible blindness. • Other symptoms include diarrhea, plugging of hair follicles with keratin forming white lumps, immune system suppression and kidney stones.

40. Vitamin A Toxicity • Toxicity can occur when taking greater than ten times the RDA. • Characterized by joint pain, headaches, dry, itchy, peeling skin, jaundice, nose bleeds, hair loss, loss of appetite, insomnia, fatigue, blurred vision, nausea, and vomiting. • Can cause birth defects in pregnant women .

41. Vitamin D • Synthesized in the body with the help of sunlight • Chief function is the mineralization of bones. • Recommended intake is 5 μg per day for both adult men and women, respectively. • Best food sources include milk, margarine, butter, cereals, veal, beef, and liver.

42. Vitamin D Deficiency • Deficiency disease known as rickets in children and osteomalacia in adults. • Rickets- vitamin D deficiency disease seen in children characterized by inadequate mineralization of bone manifested in bowed legs or knock knees.

43. Vitamin D Deficiency • Osteomalacia- a bone disease characterized by softening of the bones. Symptoms include bending of the spine and bowing of the legs, occuring most often in adult women.

44. Vitamin D Toxicity • Likely to be toxic when consumed in amounts above the recommendations • Characterized by nausea, vomiting, increased blood calcium and phosphorus, loss of appetite, headache, muscle weakness, joint pain, excessive thirst, and irreversible kidney damage

45. Vitamin E • One of the body’s primary antioxidants • Evidence suggests that vitamin E can reduce the risk of heart disease. • Recommended intake is 10 mg α TE and 8 mg α TE per day for adult men and women, respectively. • Best food sources are wheat germ oil, soybean oil, corn oil, and sunflower seeds.

46. Vitamin E Deficiency • Deficiency is rare but may be encountered in cases of fat malabsorption. • Characterized by a hemolytic anemia • Prolonged deficiency can cause neuromuscular dysfunction, impaired vision and speech

47. Vitamin E Toxicity • Toxicity is rare. • Can occur with supplementation • May interfere with the blood clotting action of vitamin K

48. Vitamin K • Primary function is the synthesis of blood clotting proteins • Participates in the synthesis of bone proteins • Can be obtained from non food sources such as the bacteria in the GI, however, that can only meet 1/2 of a person’s needs.

49. Vitamin K {continued} • Recommended intakes are 80 μg and 65 μg per day for adult men and women, respectively. • Best food sources are liver, leafy green vegetables, and cabbage like vegetables.

50. Vitamin K Deficiency • Deficiency is rare but it may be encountered in cases of fat malabsorption, which would diminsh vitamin K absorption. • Antibiotics kill the vitamin K producing bacteria in the intestine. • Deficiency would be characterized by hemorrhaging.