The Water-Soluble Vitamins: B Vitamins and Vitamin C

1. The Water-Soluble Vitamins: B Vitamins and Vitamin C Chapter 10

2. The Vitamins – An Overview • Vital to health, organic, and available in foods • Vitamins differ from macronutrients • Structure • Function • Food contents • Both deficiency and excess of vitamins can affect health

3. The Vitamins – An Overview • Bioavailability • Quantity provided by food • Amount absorbed and used by body • Factors influencing bioavailability

4. The Vitamins – An Overview • Precursors • AKA Provitamins • Organic nature • Can be destroyed during storage and in cooking

5. The Vitamins – An Overview • Solubility • Affects absorption, transport, and excretion • Water-soluble (B vit & vit C) VS Fat-soluble • Consumption frequency of vitamins

6. The Vitamins – An Overview • Toxicity • More is not necessarily better • Excessive intakes

7. The B Vitamins – As Individuals • Very active in the body, but do not provide the body with fuel for energy. • Several B vitsform part of the coenzymes • Others participate in metabolism and cell multiplication. • Recommendations for B vitscome from RDA, AI, and Tolerable Upper Intake Levels. • deficiencies, toxicities, and food sources are unique for each

8. The B Vitamins – As Individuals

9. The B Vitamins – Thiamin • Part of coenzyme thiamin pyrophosphate (TPP) • Energy metabolism • Nerve activity and muscle activity • Recommendations: • RDA Men: 1.2 mg/day. • RDA Women: 1.1 mg/day.

10. The B Vitamins – Thiamin • Deficiency • Malnourished and alcoholics • Deficiency symptoms: • Enlarged heart and possible cardiac failure. • Muscular weakness. • Apathy, poor short-term memory, confusion, and irritability. • Anorexia and weight loss. • Wernicke-Korsakoff syndrome is a severe deficiency that develops in those who abuse alcohol. • Deficiency results in the disease beriberi (dry & wet) • Toxicity • None reported

11. The B Vitamins – Thiamin • Food sources: • Whole-grain, fortified or enriched grain products • Moderate amounts in all foods • Pork • Other Information: • easily destroyed by heat) • Leaches into water • Steaming and microwaving

12. The B Vitamins – Thiamin

13. The B Vitamins – Riboflavin • Riboflavin (Vitamin B2): • Involved in energy metabolism. • Coenzyme forms: • Flavinmononucleotide (FMN)& flavinadenine dinucleotide (FAD) • Recommendations • RDA Men: 1.3 mg/day; Women: 1.1 mg/day • Deficiency • Inflammation of membranes • Deficiency symptoms • Deficiency disease is ariboflavinosis. • Toxicity • No reported toxicities

14. The B Vitamins – Riboflavin • Food sources • Milk and milk products, including yogurt and cheese • Whole-grain, fortified, and enriched grain products • Liver • Destruction of riboflavin • Destroyed • Not destroyed by cooking

15. The B Vitamins – Riboflavin

16. The B Vitamins – Niacin(Vitamin B3) • Two chemical structures • Nicotinic acid • Nicotinamide • Two coenzyme forms – metabolic reactions • Nicotinamide adenine dinucleotide (NAD) • NADP (the phosphate form)

17. The B Vitamins – Niacin • Recommendations • Body manufacturers from tryptophan • RDA is stated in niacin equivalents • RDA Men: 16 NE/day. • RDA Women: 14 NE/day. • Upper level of 35 mg/day for adults.

18. The B Vitamins – Niacin • Deficiency • Pellagra • Symptoms Deficiency symptoms: • Toxicity • Supplements or drugs • Niacin flush • Toxicity symptoms • Potential health benefits of large doses of nicotinic acid:

19. The B Vitamins – Niacin • Food sources • Milk, eggs, meat, poultry, and fish • Whole-grain and enriched breads and cereals • Nuts and all protein-containing foods • Other Information • Also called nicotinic acid, nicotinamide, and niacinamide. • The amino acid tryptophan is the precursor. • The vitamin can be lost from foods when it leaches into water.

20. The B Vitamins – Niacin

21. The B Vitamins – Biotin • As part of a coenzyme used in energy metabolism • Coenzyme that carries activated carbon dioxide • Critical in TCA cycle • Participates in gluconeogenesis and fatty acid synthesis • Participates in breakdown of fatty acids and amino acids

22. The B Vitamins – Biotin • Recommendations – AI Adults: 30 g/day. • Deficiency and Toxicity • Deficiencies are rare. • Deficiency symptoms: • No reported toxicities.

23. The B Vitamins – Biotin • Biotin can be bound with an egg-white protein called avidin. • Food Sources: • Widespread in foods. • Organ meats, egg yolks, and fish. • Soybeans. • Whole grains. • Biotin can also be synthesized by intestinal bacteria.

24. The B Vitamins – Pantothenic Acid • Part of chemical structure of coenzyme A, used in E metabolism • Recommendations • AI: Adults 5mg/day • Deficiency • Rare • Symptoms:

25. The B Vitamins – Pantothenic Acid • Toxicity • None reported • Food sources (Widespread in foods): • Chicken, beef, liver, and egg yolks. • Potatoes, tomatoes, and broccoli. • Whole grains and oats. • Can be destroyed by freezing, canning, and refining.

26. The B Vitamins – B6 • Three forms: Pyridoxal, pyridoxine, and pyridoxamine • Recent research claiming influence on cognitive performance, immune funx, steroid hormone activity. • Stored exclusively in muscle tissue

27. The B Vitamins – B6 • Recommendations • Adults (19-50yrs): 1.3mg/day • Deficiency • Symptoms: • Alcohol destroys the vitamin. • Isoniazid (INH) drug used for tuberculosis acts as an antagonist.

28. The B Vitamins – B6 • Toxicity • Upper level for adults: 100 mg/day. • Food sources • Meats, fish, poultry, and liver • Legumes and soy products • Non-citrus fruits • Fortified cereals, potatoes and other starchy vegetables.

29. The B Vitamins – B6

30. The B Vitamins – Folate • Known as folacin or folic acid • Primary coenzyme form – THF (tetrahydrofolate) • Transfers single-carbon compounds during metabolism

31. The B Vitamins – Folate • Recommendations • RDA Adults: 400 g/day. Dietary Folate Equivalents (DFE) • Higher recommendations for pregnant women. • Folate and Neural Tube Defects • Pregnant women should take folate supplements.

32. The B Vitamins – Folate • Folate and Heart Disease • High levels of homocysteine and low levels of folate increase risk of heart disease. • Folate breaks down homocysteine. • Folate may help to prevent cancer, but may also promote cancer growth once cancer has developed.

33. The B Vitamins – Folate • Deficiency • Elevated homocysteine levels. • Most vulnerable of all the vitamins to interactions with medications. • Toxicity • Masks vitamin B12 deficiency symptoms.

34. The B Vitamins – Folate • Toxicity: • Upper level for adults: 1000 g/day. • Food Sources • Fortified grains • Leafy green vegetables • Legumes and seeds • Liver • Easily destroyed by heat and oxygen.

35. The B Vitamins – Folate

36. The B Vitamins – Vitamin B12 • Cobalamin – • Methylcobalamine and deoxyadenosylcobalamin are the coenzyme forms. • Recommendations • RDA Adults: 2.4 g/day.

37. The B Vitamins – Vitamin B12 • Deficiency symptoms • Anemia • Fatigue and degeneration of peripheral nerves progressing to paralysis. • Sore tongue, loss of appetite, and constipation. • Deficiency disease is called pernicious anemia.

38. The B Vitamins – Vitamin B12 • No known toxicities • Food Sources. • Meat, fish, poultry, and shellfish. • Milk, cheese, and eggs. • Fortified cereals. • Other Information • Binds with intrinsic factor • Easily destroyed by microwave cooking.

39. The B Vitamins – In Concert • Each B vitamin coenzyme is involved in energy metabolism • Directly • Indirectly • Deficiencies • Single B-vitamin deficiencies seldom show up in isolation

40. The B Vitamins – In Concert • The B Vitamins are interdependent • Presence of one may affect the absorption, metabolism, and excretion of another. • A deficiency of one may affect the functioning or deficiency of another. • A variety of foods from each food group will provide an adequate supply of all the B vitamins.

41. The B Vitamins – In Concert • B Vitamin Roles • Coenzymes involved directly or indirectly with energy metabolism. • Facilitate energy-releasing reactions. • Build new cells to deliver oxygen and nutrients for energy reactions. • B Vitamin Deficiencies • Deficiencies rarely occur singly except for beriberi and pellagra. • Can be primary or secondary causes. • Glossitis and cheilosis are two symptoms common to B vitamin deficiencies. • Symptoms that individuals experience are not necessarily related to a vitamin deficiency.

42. The B Vitamins – In Concert • B vitamin toxicities can occur with supplements. • B Vitamin Food Sources • Grains group provides thiamin, riboflavin, niacin and folate. • Fruits and vegetables provide folate. • Meat group provides thiamin, niacin, vitamin B6, and vitamin B12. • Milk group provides riboflavin and vitamin B12.

44. The B Vitamins – In Concert

45. Vitamin C – Roles • Antiscorbutic factor is the original name • Roles • Serves as a cofactor to facilitate the action of an enzyme • Antioxidant • As a Cofactor in Collagen Formation

46. Vitamin C • As a Cofactor in Other Reactions • Hydroxylation of carnitine • Converts tryptophan to neurotransmitters • Makes hormones • Needs increase during body stress, • i.e. infections, burns, extremely high or low temperatures, heavy metal intakes, certain medications, and smoking

47. Vitamin C • In the Prevention and Treatment of the Common Cold • Role in disease prevention is still being researched • Vitamin C Recommendations • RDA Men: 90 mg/day; Women: 75 mg/day • Smokers: +35 mg/day • Deficiency • Disease is called scurvy • Deficiency symptoms

48. Vitamin C – Deficiency

49. Vitamin C • Toxicity • Upper level for adults: 2000 mg/day • Food Sources • Citrus fruits, cantaloupe, strawberries, papayas, and mangoes • Cabbage-type vegetables, dark green vegetables like red peppers and broccoli, lettuce, tomatoes, and potatoes • Other information • Also called ascorbic acid • Easily destroyed by heat and oxygen

50. Vitamin C – Food Sources