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Vitamins

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Vitamins

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  1. Vitamins

  2. Dietary Supplement Use (USA) • $ 4,300,000,000 for vit/min in 1995 • $ 1,400,000,000 for herbs • $ 31,000,000,000 total for dietary supplements and functional foods in 1999 (GAO, 2000) • 42% adults regular users (27% 1989) • females > males • 66% multi-vit/min • 37% vitamin C • 19% vitamin E • 23% herbal supplements (13% 1995)

  3. Dietary Supplement Use: Pros • Supplements prevents dietary deficiencies • calcium • folic acid • Amounts used in some studies not attainable with dietary sources • antioxidants • Relatively low cost

  4. Dietary Supplement Use: Cons • False sense of security • folic acid and pregnancy • Does not contain all potentially useful chemicals in foods • plant phytochemicals • Toxicity almost only due to supplement use • Costs significant to low income

  5. Vitamin/Mineral Deficiency Worldwide • 1 in 5 adults malnourished • 1 in 4 children malnourished • 3 million children severe vitamin A deficiency • blindness • stunted growth • 275 million with mild deficiency

  6. Vitamins: Definition • Organic compound found in foods • Required in small amounts • Required in the diet (essential) • Proven to be required for health, growth, and reproduction • deficiency syndrome identified

  7. Water Soluble Vs. Fat Soluble • Water Soluble: • Vitamin C, and the B vitamins • Fat Soluble • Vitamins A,D,E,K

  8. Vitamins: Support Staff • What can’t they do? • They can’t be used as an energy source. • What can they do? • They are usually in supporting roles in the body. • e.g.: many of the B vitamins are co-enzymes that help breakdown glucose for energy

  9. The differences between water and fat soluble vitamins • Absorption from digestive system • fat soluble: into the lymph with chylomicrons • H20 soluble: into blood • Transport • fat sol: carried by lipoproteins • water sol: free in blood

  10. Water Vs Fat Soluble • Storage and Excretion • Fat Sol: stored with fat in cells and adipose tissue, excesses stored • Water sol: not held firmly by cells, excesses excreted • Potential for Fat soluble to build up and perhaps reach toxic levels • Potential for water soluble to excrete extra amounts, not as prone to toxicity

  11. Fat soluble Toxicity • Fat soluble vitamins may be toxic with too high of an intake • Water soluble vitamins are less likely to be toxic with high intake

  12. B Vitamins • Correct names and common names • Thiamin B1 • Riboflavin B2 • Niacin nicotinic acid • B6 pyridoxine • folacin folate, folic acid • B12 cobalamin

  13. B vitamins: Correct names • pantothenic acid no other • biotin no other • B vitamins act as coenzymes • Help to complete the correct shape of the molecule • Many help to metabolize glucose to release energy

  14. B Vitamins • Coenzyme function • Prosthetic Group: physically become part of an enzyme complex • Others are more loosely attached • May be part of the active site in the enzyme.

  15. Vitamins and Metabolism

  16. B Vitamins • Thiamin • Riboflavin • Vitamin B 6 (pyridoxine) • Folate

  17. B vitamin deficiencies • Thiamin: beriberi • symptoms: mental confusion, muscle weakness and wasting, edema, enlarged heart

  18. Riboflavin: • symptoms: personality changes, cracks at the corners of your mouth(cheilosis), tender tongue(glossitis)

  19. Folacin: • Symptoms: megaloblastic, macrocytic anemia,

  20. Niacin • Part of NAD+ • helps metabolize glucose • without Niacin, this breakdown of glucose stops • Slows energy release: 4 D’s of Niacin deficiency (called pellagra: • Dermatitis: skin inflammation • Diarrhea: poor absorption • Dementia: no energy to think • Death: if untreated

  21. Pellagra

  22. Vitamin B 12 • Blood formation • Homocysteine • Nerve damage • Deficiency • Atrophic gastritis • Pernicious anemia

  23. Megaloblastic anemia

  24. Vascular Disease • Folate and vitamin B12 are required for the breakdown of the amino acid homocysteine. • Low folate and vitamin B12 intake may cause an increased level of homocysteine. • High homocysteine levels are associated with greater risk of cardivascular and cerebrovascular disease.

  25. B vitamin Toxicities: Rare • B6 • Symptoms: with very high doses sensory nerve disorders; may interfere with nerve impulses and heart beat • Niacin • Symptoms: skin flushing, nausea, jaundice, liver dysfunction • Some individuals with high serum cholesterol are treated with pharmacological doses of niacin

  26. Oxidation • Oxidation: the loss of electrons from a molecule. • Reduction: the gain of electrons by a molecule. • Oxidation and reduction usually occur together as an exchange reaction.

  27. Oxidation • Stable atoms contain an even number of paired electrons. • Free radical:an atom that has lost an electron and is left with an unpaired electron. • Free radicals are highly reactive and can cause damage to molecules in the cell.

  28. Free Radicals and Diseases

  29. Antioxidants • Substances that are able to neutralize reactive molecules and reduce oxidative damage • Result of metabolic processes and environmental sources • Vitamin C, Vitamin E, beta-carotene, Vitamin A, selenium, iron, zinc, copper and manganese

  30. Vitamin C Functions • Collagen Formation • antioxidant • reduce cancer risk • helps absorb iron from food • Reduces risk of colds????? • probably not • Linus Pauling’s study • NutraIngredients

  31. Vitamin C • Deficiency: called scurvy • poor formation of collagen in blood vessels • weak vessels result in hemorrhages • can be severe and result in lots of blood loss and death • Toxicity: may result in • kidney stones • rebound scurvy • Destruction of B12 • Problems with acid/base balance

  32. Vitamin C: RDA 90/75 mg/day • Foods rich in vitamin C: • 1 cup fresh squeezed orange juice: 124 mg • 1 cup canned o.j.: 84 mg • Smoker’s RDA = +35 mg/day • Some of vitamin C is sacrificed in reducing the oxidants of cigarette smoke • Vitamin C intake offers protection against stomach cancer

  33. Vitamin C • Deficiency: called scurvy • poor formation of collagen in blood vessels • weak vessels result in hemorrhages • can be severe and result in lots of blood loss and death • Toxicity: may result in • kidney stones • rebound scurvy • Destruction of B12 • Problems with acid/base balance

  34. Vitamin C: RDA 60 mg/day • Foods rich in vitamin C: • 1 cup fresh squeezed orange juice: 124 mg • 1 cup canned o.j.: 84 mg • Smoker’s RDA = 100 mg/day • Some of vitamin C is sacrificed in reducing the oxidants of cigarette smoke

  35. Vitamin A Functions • Vision: helps with conversion of light energy to electrical energy in eye • Cell differentiation-maintenance of linings: • helps produce the CHO normally found in mucous • Bone growth: • helps with remodeling growing bones

  36. Vitamin A Deficiency • One year supply in fat and liver of most people: So deficiencies are rare • Bone growth and remodeling problems • shape changes • Linings deteriorate • GI tract: diarrhea • Respiratory tract: infections • urogenital tract: infections, kidney stones • Impaired night vision and day vision

  37. Vitamin A Toxicities • Bones: • decalcification, joint pain • Nervous system • loss of appetite, irritability, muscle weakness • Liver enlargement • jaundice • Blood: RBCs loose hemoglobin • Bleeding induced easily

  38. Beta-Carotene-provitamin • Functions • Weak antioxidant • Enhance immune system • Protect skin and eyes • Deficiency/toxicity

  39. Beta-Carotene-provitamin • No RDA • Sources

  40. Beta carotene and Vitamin A

  41. Vitamin A RDA= 700 RE for females; 900 RE for males. • RE= Retinol Equivalent • Retinol is the active form of vitamin A • Other molecules can be metabolized to make Retinol, thus retinol equivalents • e.g.: beta carotene can be modified to make retinol • beta carotene is found in carrots and other deep orange and green vegetables • 1 RE= 1 microgram of retinol • 1 RE= 3.3 IU retinol • 1 RE = 12 micrograms of beta carotene

  42. Vitamin A and Beta Carotene Rich Foods • 1 medium carrot = 2025 REs; about 2.5 times the RDA • 1 cup butternut squash = 1400 REs • 1 sweet potato = 2000 REs • 1/2 cup cooked spinach = 700 REs • 1 cup cooked broccoli = 250 REs • 1 cup milk = 140 REs

  43. Vitamin D Functions: Helps bone grow • Works in three ways: • 1. Increases Calcium Absorption from the G.I. tract • 2. Helps to withdraw calcium from bone • 3. Increases calcium retention in the kidney.

  44. Sources of Vitamin D • Body makes it own: • Dehydrocholesterol in the skin exposed to sunlight • Energy transforms it into a pre-vitamin D molecule • Body heat provides energy to change pre-vitamin D into inactive Vitamin D • Inactive Vitamin D activated in two steps • First, in the Liver • Second in the Kidney Netrition Home Page

  45. Vitamin D

  46. Sources of Vitamin D RDA = 5 ug-15 ug • In foods: • Fortified milk: 2.5 mcg/cup • 1 egg = 0.7 mcg • 3 oz shrimp = 3 mcg • 1 tsp margarine = 0.5 mcg • USATODAY.com - How to get vitamin D?