Vitamins

1. Vitamins

2. Vitamins • Definition: vital dietary substances • Not CHO, Protein, or Fat • Necessary in very small quantities to do special metabolic jobs • Help regulate body processes • Especially B vitamins

3. Vitamins • Cannot be made by body in sufficient amounts Exception: Vitamin D • Supplied by food • Most work by combining with protein to form co-enzymes • Natural vs. Synthetic • Rates of absorption different

4. Vitamins • Provitamins • precursors to active vitamin • Antivitamins • antagonists • Avitaminosis • deficiency • Hypervitaminosis • too much

5. Vitamins • Grouped by solubility. • Fat soluble I • A D E K • H20 soluble • B complexC • B12 folate • pantothenic acid • biotin

6. Fat Soluble • Absorbed in lymphatic system • Deficiencies occur with fat malabsorption • Attached to protein carriers • Not excreted, stored if not needed • Can be toxic

7. Water Soluble Vitamins • Absorbed directly through intestinal wall • Filtered by kidneys and excreted if excess • Tissues able to hold limited amounts • May be able to become toxic • Function as coenzymes for production of energy

8. Vitamins • Megadose • more than 10 X RDA • Up to 35% of Americans take vitamin supplements • Food best source • Supplements needed when diet inadequate or during times of stress

9. Vitamin A • Generic term for several compounds • retinal • retinol • retinaldehyde • retinoic acid

10. Vitamin A • Preformed vitamin A = retinol • found only in animal sources or fortified foods • 6-12 months supply in body • stores deplete in infectious disease • major transport and storage form • retinol binding protein picks up retinol from liver, carries it in blood

11. Vitamin A • Provitamin A • Beta carotene • Plant source • Supplies 2/3 Vitamin A necessary • Converted retinal retinol • Extremely effective antioxidant

12. Maintains cornea Helps with light detection at retina Maintains integrity of epithelial cells Fights infection Supports normal bone and body growth Reproduction Cell development Vitamin A

13. Vitamin A Deficiencies • Epithelial cells flatten and harden from production of keratin • Drying & hardening of cornea • xerosis • Xerophthalmia- • night blindness • hardening of cornea • complete blindness

14. Vitamin A Deficiencies • Mucous linings harden • increased tendency for infection • Skin • Dry, rough, scaly “toad’s skin” • Follicular hyperkeratosis • Delayed sexual maturation/sterility

15. Vitamin A Toxicity • Acne medication • can cause birth defects • Overdosing • can cause birth defects • joint pains • loss of hair • jaundice • death

16. Vitamin A Sources • Liver • Fish Liver Oils • Whole and Fortified milk and dairy products • Dark green and yellow-orange vegetables

17. Vitamin D • Made in body with help of ultraviolet rays • prohormone = calcitriol • Works in harmony with parathyroid hormone • withdraws Ca++ from bone to maintain Ca++ • calcitonin decreases bone withdrawal

18. Vitamin D • Liver manufactures precursor • Migrates to skin-converted to #2 precursor with ultraviolet rays • Liver and kidney convert #2 to active vitamin • Absorption in small intestine • Requires presence of bile salts

19. Vitamin D • Associated with Ca++ and Po4-3 metabolism • Promotes normal bone mineralization • Basic cell processes in brain & kidney, liver, skin, reproduction • Immune system

20. Vitamin D Deficiencies • Bones fail to calcify • Rickets or osteomalacia can develop • Muscle spasms and pain • Repeated pregnancies and periods of lactation • Little sun exposure

21. Vitamin D Toxicity • Stored in adipose tissue • Released slowly • Bone pain & weakness • Calcium deposits in heart or lungs • Increased serum calcium • Kidney stones • Most toxic of all vitamins

22. Vitamin D Sources • Fortified milk • Fortified margarine • Fortified breakfast cereals • Small amounts in egg yolk, salmon, tuna fish

23. Vitamin E • Generic name for 8 naturally occurring fat soluble nutrients called tocopherols • Absorbed with aid of pancreatic secretions and bile salts • Stored in adipose tissue

24. Vitamin E • Great antioxidant • Neutralizes free radicals • Works with selenium to destroy cell peroxides • Protects lung from air pollutants • Protects RBC • Research on Vitamin E role in decreasing heart disease

25. Vitamin E • Decreased # of sickle cells • Helps in cystic fibrosis • Benefit in boosting immune function and fighting Alzheimer’s

26. Vitamin E Deficiencies • RBC break open • Erythrocyte hemolysis in premature infants (hemolytic anemia) • Affects vision • Neurology problems

27. Vitamin E Toxicity • Interferes with blood clotting action of Vitamin K • leads to hemorrhage with anticoagulant drugs • MYTHS: • improves athletic skill • enhances sexual performance • prevents wrinkling or gray hair

28. Vitamin E Sources • Vegetable oils • Milk • Eggs • Fish • Cereal grains

29. Vitamin K • Phylloquinone • Essential for synthesis of 5 proteins involved in blood clotting • Involved with CA++ in bone development

30. Vitamin K • Absorbed in small intestine • Needs bile salts for absorption • Stored in liver • Small amount-10 days supply • Can be synthesized in intestinal tract from dietary sources

31. Vitamin K Deficiencies • Needed daily • Extended use of antibiotics • Malabsorption -defects in fat absorption • In sterile digestive tract in newborns • Hemorrhage Disease of newborns

32. Vitamin K Toxicity • Red cell hemolysis • Jaundice • Brain damage

33. Vitamin K Sources • Green leafy vegetables • Liver • Milk • Meats • Egg yolk

34. Vitamin C • Absorbed from small intestine • ~ 3 months for deficiencies to appear • Antioxidant • Collagen, connective tissue • Removes Fe++ from ferritin, activates folate

35. Vitamin C • Important in wound healing • Antihistamine effect • Depleted in • Infectious processes • Smokers • Burns • Surgery • How much to supplement unknown

36. Vitamin C • Megadosing can cause hyperosmolar diarrhea • Rebound scurvy or rash when large doses stopped quickly • Fe++ overload

37. Vitamin C • Supplemented in patients with • skin ulcers • along with vitamin C, vitamin A, zinc • spinal cord injuries • increase acid in urine

38. Vitamin C Deficiencies • Scurvy- bleeding gums • Pinpoint hemorrhages under skin • Rough, brown scaly skin • Massive bleeding into joints,body cavities

39. Vitamin C Sources • Citrus fruits • Potatoes • Broccoli • Tomatoes • Green peppers

40. Vitamin B1 Thiamin • Combined with PO4 in jejunal mucosa • forms TPP • acts in process that converts • pyruvate to acetyl CoA energy

41. Vitamin B1 Deficiencies • Anorexia • Severe constipation • Lower HCL acid secretion • General apathy & fatigue • Severe: beriberi • paralysis and cardiac failure • lower extremity edema • muscle pain

42. Vitamin B1 • Give thiamin to ETOH abusers • Supplement in: • chronic illness • gestation • lactation • strange diets

43. Vitamin B1 Sources • Lean meats • Liver • Whole or enriched grains

44. Vitamin B2 Riboflavin • Facilitates energy production • 2 enzymes operate at vital reaction points of citric acid cycle • De-amination of A2 • Light sensitive, destroyed ultraviolet rays and fluorescent light

45. Vitamin B2 Deficiencies • Tissue inflammation/breakdown • Delayed wound healing • Characteristic cracks at corners of mouth-cleilosis • Tongue becomes red swollen -glossitis • Eyes burn, itch, tear

46. Vitamin B2 Deficiencies • Scaly, greasy skin-seborrheic dermatitis in skin folds • Supplement in GI diseases, pregnancy, and lactation

47. Vitamin B2 Sources • Milk • Meat • Whole grain/enriched breads • Dark green leafy vegetables

48. Niacin • Participates in energy metabolism • Small amount made from tryptophan • Active in citric acid cycle • Used in CVD to lower CHOL • Acts as vasodilator-causes skin flushing • Can injure liver

49. Niacin Deficiencies • Weakness and anorexia • Skin eruptions • Dark scaly dermatitis • Severe-confusion, pellagra • 4 D’s = dermatitis, diarrhea, dementia, death

50. Niacin Sources • Peanuts • Beans • Peas • Enriched grains