1. VITAMINS Chap 8 J Pistack MS/Ed

2. Vitamins Organic substances—derived from living matter and contain carbon Small amounts required for normal metabolism, growth, and maintenance Coenzymes (substances that activate enzymes) and regulators of metabolic processes Do not provide energy Do not become part of body structure Specific functions nontransferable— deficiency diseases

3. Vitamin Classifications Fat soluble (A, D, E, and K)—more stable to environmental influences; absorbed with fat; stored in body Water soluble (B vitamins and C)— less stable to environmental influences; only B 12 stored for any length of time

4. Vitamin A Chemical necessary for vision Health of epithelial tissue—skin, lining of gastrointestinal tract Normal bone growth Metabolism of adipose tissue

5. Vitamins A preformed vitamin is already in a complete state in ingested foods A provitamin requires conversion in the body to become complete. A provitamin is also called a precursor because it is a substance from which another substance is derived

6. Vitamin A Food Sources Preformed vitamin A—liver, egg yolk, fortified milk Provitamin A Carrots, sweet potatoes, squash Apricots, cantaloupe Spinach, collards, broccoli, cabbage

7. Vitamin A Deficiency Diseases Night blindness Xerophthalmia - Extreme dryness and thickening of the conjunctiva, often resulting from a deficiency of vitamin A In developed countries, disease or lack of treatments can cause deficiencies

8. Vitamin A Deficiency Vitamin A deficiency diseases in addition to vision: Vitamin A deficiency diseases in addition to vision: Anorexia Anorexia Growth retardation Growth retardation Increased susceptibility to infection Increased susceptibility to infection Disorders of the skin and hair follicles Disorders of the skin and hair follicles Taste impairment Taste impairment Balance disturbances Balance disturbances Bone changes that impinge on cranial nerves (increased osteoblastic activity) Bone changes that impinge on cranial nerves (increased osteoblastic activity) Increased intracranial pressure Increased intracranial pressure Fertility Fertility

9. Prevention and Treatment of Vitamin A Deficiency in Developing Countries Prevention Breastfeeding Supplementation Food fortification Diet diversification Treatment High-dose vitamin A Active corneal disease is a medical emergency

10. Vitamin A Toxicity Carotenemia - too many yellow vegetables; (squash and carrots) usually benign Hypervitaminosis A - can be fatal S/S similar to brain tumor Liver disease Additional information: www.sightandlife.org

11. Vitamin D Functions Increases intestinal absorption of calcium and phosphorus Stimulates bone cells to build tissue Signals kidney to return calcium to bloodstream, not excrete it in urine

12. Vitamin D Deficiency Rickets—in children: still a risk, especially to dark- skinned breastfed infants Osteomalacia—in adults: low D intake and/or little sun exposure can cause a bone disease in adults analogous to rickets in children, marked by bone demineralization caused by impaired metabolism or deficiency of vitamin D or phosphorus.

13. vitamin D excess Disorders due to vitamin D excess One of the most likely vitamins to cause toxicity Loss of appetite Nausea/vomiting Polyuria Muscle weakness Constipation More serious issues consist of calcium deposits in the heart, kidneys, and brain

14. Vitamin D Sources Sunlight on skin—daily sun exposure Arms, shoulders, and back without sunscreen Between 11 a.m. and 2 p.m. for 15 minutes in summer and 20 minutes in spring and fall Fortified foods—milk combines vitamin with calcium Supplements—cod liver oil vitamin/mineral supplement

15. Vitamin E Functions Antioxidant - take on oxygen preventing surrounding molecules from becoming unstable Protects cell membranes (plays a role in vitamin E, provitamin A, and unsaturated fatty acids stability In lungs, barrier against air pollution Protects red blood cells from oxidation in lungs

16. Vitamin E Deficiency Hemolytic anemia - Anemia resulting from the lysis of red blood cells Degenerative neurological problems Anemia in premature infants

17. Vitamin E Toxicity Excessive supplemental vitamin E can cause Gastrointestinal symptoms Muscle weakness Double vision Increased bleeding tendencies

18. Vitamin E Sources Vegetable oils—canola and olive oils highest in alpha-tocopherol (one of the components of vitamin E and is present in vegetable oils, nuts, and seeds or produced synthetically. It is the predominant form of vitamin E in the human body and in supplements.) Whole grains Especially fortified ready-to-eat cereals Wheat germ Nuts Leafy vegetables

19. Vitamin K Functions Blood clotting—Necessary for the liver to make prothrombin and other clotting factors Bone metabolism—Facilitates synthesis of a calcium-binding protein (Osteocalcin)

20. Vitamin K Note - Vitamin K can be given to serve as an antidote for warfarin overdose

21. Vitamin K Deficiency Bleeding problems can occur in Newborns Long-term antibiotic therapy users People with malabsorption syndromes

22. Vitamin K Sources Intestinal synthesis Varies from person to person Not sufficient as sole source Food sources—green leafy vegetables Broccoli, Brussels sprouts Cabbage, collards Salad greens, spinach

23. Vitamin K Toxicity Not from naturally occurring forms Vitamin K1 (plants) Vitamin K2 (intestinal synthesis) Pharmaceutical K1 (phytonadione) not recommended intravenously except in emergency due to life- threatening reactions

24. Vitamin C Functions Collagen synthesis—strong, fibrous protein in connective tissue Antioxidant—more sensitive to oxidation than vitamins A and E Iron absorption—acts with HCl to keep iron in more absorbable form Aids in the synthesis of norepinephrine and serotonin

25. Vitamin C Deficiency Signs and symptoms of scurvy Early—bleeding gums, petechiae (small hemorrhage) Late—delayed or reversed wound healing, bone pain and fractures, tooth loss, hemorrhage Treatment—vitamin C Current cases of scurvy Due to restricted eating patterns Delayed diagnosis due to low suspicion

26. Vitamin C Sources Fruits—citrus, cantaloupe, kiwi fruit, papayas, strawberries Vegetables—broccoli, Brussels sprouts, green and red peppers Boiling, cooking, and canning fruits and vegetables lowers vitamin C content by 33%

27. Vitamin C Toxicity S/S—nausea, abdominal cramps, diarrhea Megadoses contraindicated if at risk for Iron overload Kidney stones

28. Thiamin Functions Coenzyme in metabolism of : Carbohydrates Glucose Branched chain amino acids

29. Thiamin Deficiencies At risk Alcoholics People subsisting on milled rice Lack of glucose for central nervous system Wernicke encephalopathy—motor and sensory deficits involving eye muscles, balance, and memory Korsakoff psychosis—amnesia and impaired conceptual functions

30. Thiamin Deficiencies Beriberi – broad classification of thiamin deficiency Dry beriberi – muscle weakness Wet beriberi – cardiovascular system culminating in right-sided heart failure Infantile beriberi – loud cry and convulsions

31. Thiamin Sources Meat/legumes—pork, black beans, black- eyed peas Other plant sources—wheat germ, enriched grain products Fortified foods—cereals

32. Riboflavin Function Coenzyme in metabolism of protein and other vitamins Deficiency Usually combined with other vitamin deficiencies like thiamin and niacin If alone it’s called Ariboflavinosis

33. Niacin Function—coenzyme in energy metabolism Deficiency—pellagra 3 Ds—dermatitis (glove), diarrhea, dementia 4th D—death Sources of niacin—meat; fish; poultry; whole, enriched, or fortified grains; coffee; tea

34. Vitamin B6 Function—coenzyme in the metabolism of amino acids Deficiency—rare except for drug interactions and food-processing errors

35. Vitamin B6 Sources and Toxicity Sources of vitamin B6—widely distributed in foods, especially fortified beverages and cereals Toxicity None reported from foods

36. Folate/Folic Acid Functions—necessary for the formation of DNA, thus participates in the reproduction of every cell Deficiency Link to neural tube defects (NTDs) - A group of birth defects that affect the backbone and sometimes the spinal chord. Discovery of this led to recent change in enrichment of grains Megaloblastic anemia

37. Folate/Folic Acid Sources and Toxicity Sources of folate Liver, dried peas, beans, lentils Green leafy vegetables Fortified grains Toxicity of folic acid None reported from food or supplement s

38. Vitamin B12 Function and Deficiencies Functions—Required for Synthesis of DNA, RNA Metabolism of amino acids and fatty acids Synthesis and maintenance of myelin Deficiency Other pathology—gastric resection, gastric atrophy, Crohn’s disease Dietary causes—elimination of animal products

39. Wise Use of Supplements Select a multivitamin/multimineral preparation Take recommended dosages, not to exceed 150% (one and one-half times) the RDA Mention when asked medication history