1. VITAMINS

2. Definition and Classification
Non-caloric organic nutrients
Needed in very small amounts
Facilitators – help body processes proceed; digestion, absorption, metabolism, growth etc.
Some appear in food as precursors or provitamins

3. Definition and Classification
2 classes
Fat soluble:
Water soluble:

4. Definition and Classification
Fat soluble vitamins
Found in the fats and oils of food.
Absorbed into the lymph and carried in blood with protein transporters = chylomicrons.
*Stored in liver and body fat and can become toxic if large amounts are consumed.

5. Definition and Classification
Water soluble vitamins
Found in vegetables, fruit and grains, meat.
Absorbed directly into the blood stream
Not stored in the body and toxicity is rare. Alcohol can increase elimination, smoking, etc. cause decreased absorption.

6. Fat Soluble Vitamins Vitamin A
3 forms: retinol (stored in liver), retinal, retinoic acid
Roles in body:
Regulation of gene expression
Part of the visual pigment rhodopsin, maintains clarity of cornea (yes eating carrots is good for your eyesight)
Required for cell growth and division - epithelial cells, bones and teeth
Promotes development of immune cells, especially “Natural Killer Cells”
Antioxidant

7. Fat Soluble Vitamins Vitamin A Deficiencies cause:
Night blindness, xerophthalmia (keratin deposits in cornea), muscular degeneration.
Skin and mucous membrane dryness and infection, keratin deposits.
Anemia
Developmental defects – bones, teeth, immune system, vision

8. Fat Soluble Vitamins Vitamin A
Toxicities (RetinA/Accutaine, single large doses of supplements, eating excessive amounts of liver) cause:
Fragile RBCs, hemorrhage
Bone pain, fractures
Abdominal pain and diarrhea
Blurred vision
Dry skin, hair loss
Liver enlargement

9. Fat Soluble Vitamins Vitamin A
DRI: 700(women)-900(men) micrograms/day, UL 3000 micrograms/day
DRI=DIETRY REFERENCE INTAKE
UL= Upper intake level

10. Snapshot 7-1, p, 219

11. Fat Soluble Vitamins
Vitamin D – precursor is cholesterol, converted by UV from sunlight exposure, therefore is a “non-essential” vitamin.
Roles:
Increases calcium absorption in bone, intestines, kidney. Promotes bone growth and maintenance.
Stimulates maturation of cells – heart, brain, immune system, etc.

12. Fat Soluble Vitamins Vitamin D
Deficiencies: rickets (children), osteomalacia (adults). What are some of the causes of deficiencies?
Toxicities (5X DRI)
Loss of calcium from bone and deposition in soft tissues.
Loss of appetite, nausea and vomiting, psychological depression.
Bowed legs – Characteristic of rickets

13. Beaded ribs – Characteristic of rickets
FIGURE 7-5: RICKETS. This child displays the beaded ribs common in rickets.
Fig. 7-5b, p. 222

14. Fat Soluble Vitamins Vitamin D
DRI – 5 micrograms/day for ages 19-50, 10 for ages 51-70, 15 for ages >70.
Sources, see snapshot 7.2

15. Snapshot 7-2, p, 223

16. Fat Soluble Vitamins
Vitamin E – tocopherol, *alpha-, beta -, gamma-, and delta-
Roles:
Antioxidant (protects polyunsaturated fats)
Prevention of damage to lungs, RBCs, WBCs (immunity), heart
Necessary for normal nerve development

17. Fat Soluble Vitamins Vitamin E
Deficiencies (decreased absorption of fats- liver disease, low fat diets)
Premature babies – fragile RBCs (hemolysis)
Loss of muscle coordination, vision, immune functions
Toxicities (more than 1000 milligrams/day)
Increases the effects of anticoagulants (Coumadin, Warfarin)

18. Fat Soluble Vitamins Vitamin E
DRI 15 milligrams/day (alpha-tocopherol)
Sources, see snapshot 7.3

19. Snapshot 7-3, p, 226

20. Fat Soluble Vitamins
Vitamin K – produced by bacteria in large intestine
Roles
Promotes synthesis of blood clotting proteins (**Interferes with Coumadin)
Bone formation
Deficiencies are rare but seen in infants, after prolonged antibiotic therapy, and in patients with decreased bile production.
Toxicities (>1000 mg/day): rupture of RBCs and jaundice

21. Fat Soluble Vitamins Vitamin K
DRI: 90(women) – 120(men) micrograms/day
Sources, see snapshot 7.4

22. Snapshot 7-4, p, 228

23. Water Soluble Vitamins
8 B vitamins – Tender Romance Never Fails with 6 to 12 Beautiful Pearls (Thiamin, Riboflavin, Niacin, Folate, B6, B12, Biotin, and Pantothenic acid)
Aid in metabolism of and energy release from carbohydrates, lipids, amino acids.
Mode of action – coenzymes or parts of coenzymes that are necessary for the proper activity of enzymes, fig 7.9

24. Without the coenzyme, compounds A and B don’t respond to the enzyme.
Active site
Enzyme
With the coenzyme in place, compounds A and B are attracted to the active site on the enzyme, and they react. B
Vitamin A
Coenzyme
Enzyme
The reaction is completed with the formation of a new product. In this case, the product is AB. A B
FIGURE 7-9: COENZYME ACTION.
Enzyme
The product AB is released. A B
New product
Enzyme
Fig. 7-9a, p. 233

25. Brain and other tissues metabolize carbohydrates.
Muscles and other tissues metabolize protein.
Bone tissues make new blood cells.
FIGURE 7-10: SOME ROLES OF THE B VITAMINS IN METABOLISM: EXAMPLES.
This figure does not attempt to teach intricate biochemical pathways or names of B vitamin–containing enzymes. Its sole purpose is to show a few of the many tissue functions that depend on B vitamin–containing enzymes. The B vitamins work in every cell, and this figure displays less than a thousandth of what they actually do.
Every B vitamin is part of one or more coenzymes that make possible the body’s chemical work. For example, the niacin, thiamin, and riboflavin coenzymes are important in the energy pathways. The folate and vitamin B12 coenzymes are necessary for making RNA and DNA and thus new cells. The vitamin B6 coenzyme is necessary for processing amino acids and, therefore, protein. Many other relationships are also critical to metabolism.
Liver and other tissues metabolize fat.
Digestive tract lining replaces its cells.
Fig. 7-10, p. 234

26. Water Soluble Vitamins
Thiamin and Riboflavin
Roles – energy metabolism in cells, part of nerve cell membranes.
Deficiencies
Beri beri, edema &/or muscle weakness
Alcohol abuse – Wernicke-Korsakoff syndrome
DRI thiamin:1.1(women) – 1.2(men) mg/day; riboflavin 1.1(women) – 1.3(men) mg/day
Sources: All food groups except fats and oils

27. Snapshot 7-6, p, 236

28. Snapshot 7-7, p, 237

29. Water Soluble Vitamins
Niacin – can be produced from the amino acid tryptophan.
Roles: energy metabolism
Deficiencies: Pellagra – dermatitis, diarrhea, dementia, death
Toxicities: prevents blood clotting, causes liver damage, enhances action of Coumadin

30. Water Soluble Vitamins
Niacin
DRI 14(women) -16(men) mg/day
Meats
Some vegetables and grains

31. Snapshot 7-8, p, 238

32. Water Soluble Vitamins
Folate
Role: required for synthesis of DNA
Deficiencies (drug interactions, smoking)
Anemia
Decreased immunity
Decreased digestive and cardiovascular function
Colon and cervical cancers
*Neural tube defects, & other birth defects

33. Water Soluble Vitamins
Folate
Toxicities (>1000 mg/day): rare, interferes with anticancer drugs.
DRI 400 milligrams/day
Sources, snapshot 7.8

34. Snapshot 7-9, p, 240

35. Water Soluble Vitamins
Vitamin B12 (requires intrinsic factor for absorption)
Roles: works with folate, part of insulating sheath around nerves.
Deficiencies:
Pernicious anemia
Paralysis
Nerve damage in fetus

36. Water Soluble Vitamins
Vitamin B12
DRI 2.3 micrograms/day
Sources, see snapshot 7.9
Meat and dairy

37. Snapshot 7-10, p, 242

38. Water Soluble Vitamins
Vitamin B6
Roles:
Conversion of amino acids to other amino acids
Ex.: Tryptophan to niacin
Synthesis of hemoglobin and neurotransmitters
Release of glucose from glycogen
Immune function
Promotes steroid hormone activity
Development of nervous system

39. Water Soluble Vitamins
Vitamin B6
Deficiencies
Anemia
Dermatitis
Muscle weakness
Behavioral problems
Heart disease
Toxicities (>100 mg/day) – muscle weakness, nerve damage

40. Water Soluble Vitamins
Vitamin B6
DRI 1.3 milligrams/day
Sources, see snapshot 7.10
Meat and dairy
Vegetables and fruits

41. Snapshot 7-11, p, 243

42. Water Soluble Vitamins
Biotin and Pantothenic acid
Roles:
Metabolism of carbohydrates, fats and proteins
Synthesis of lipids, neurotransmitters, steroid hormones, hemoglobin.

43. Water Soluble Vitamins
Vitamin C, ascorbic acid – history of controversy
Roles:
Connective tissue development, collagen
Antioxidant
Promotes iron absorption, immunity
Protects vitamin E

44. Water Soluble Vitamins
Vitamin C
Deficiency – Scurvy (skin and mucous membrane damage), anemia.
Toxicity (> 2grams/day) – pro-oxidant, activates oxidizing agents.
DRI – 75(w) – (90(m) milligrams/day. Increased for smokers.
Sources, see snapshot 7.11
Notes: can interfere with diagnostic tests for diabetes, and blood clotting
Prevents colds

45. Snapshot 7-5, p, 232