Vitamins Deficiencies & Toxicities

1. VitaminsDeficiencies & Toxicities

2. Vitamins • Organic molecules needed in small quantities for normal metabolism and other biochemical functions, such as growth or repair of tissue • Attach to enzymes or coenzymes and help them activate anabolic (tissue-building) processes

3. Vitamins • Essential part of enzymatic reactions • Natural sources from both plants and animals • Insufficient amounts result in various deficiencies

4. Vitamins (cont'd) • Vitamin K and vitamin B complex vitamins obtained by synthesis in the small intestine • Vitamin D can be synthesized by the skin when exposed to sunlight

5. Water-Soluble Vitamins • B-complex group and vitamin C • Can be dissolved in water • Cannot be stored by the body in large amounts • Daily intake required to prevent deficiencies

6. Fat-Soluble Vitamins • Vitamins A, D, E, K • Present in both plant and animal foods • Stored in the liver and fatty tissues • Daily intake not required

7. Fat-Soluble Vitamins (cont'd) • Deficiency occurs only after prolonged deprivation • Can become toxic if excessive amounts are consumed

8. Vitamins: Other Issues • Nutrient mega dosing • Toxic hypervitaminosis

9. Vitamin A • Fat soluble • Vitamin A (retinol) derived from animal fats (butter and milk), eggs, meat, liver, fish liver oils • The vitamin A in animal tissues is derived from carotenes, which are found in plants (green and yellow vegetables and yellow fruits)

10. Vitamin A • Required for growth and development of bones and teeth • Necessary for other processes • Reproduction • Integrity of mucosal and epithelial surfaces • Cholesterol and steroid synthesis • Essential for night vision

11. Vitamin A: Deficiency states • Hyperkeratosis of the skin • Night blindness • Skin conditions • Acne, psoriasis, keratosis follicularis

12. Vitamin A: Toxicity • Ingestion of excessive amounts causes toxicity • Irritability, drowsiness, vertigo, delirium, other symptoms • Increased intracranial pressure in infants • Generalized peeling of the skin and erythema over several weeks

13. DIAGNOSIS • Abnormalities of dark adaptation are strongly suggestive of vitamin deficiency .Serum level below the normal range of 30-65mg/dl are commonly seen in advance deficiency.

14. TREATMENT • Orally: DOSE 30,000 iu of vit A daily for 1 week. • Advance deficiency with corneal damage -20,000 ius/kg orally for 5 days.

15. Vitamin D • Fat soluble • “Sunshine vitamin” • Responsible for proper utilization of calcium and phosphorus • Actually a group of analog steroid chemicals

16. Vitamin D (Fat Soluble) • Different chemicals, produce same effect • Vitamin D2 (ergocalciferol) • Plant vitamin D • Obtained through dietary sources • Vitamin D3 (cholecalciferol) • Produced in the skin by ultraviolet irradiation (sunshine)

17. Vitamin D (cont'd) • Vitamin D2-containing foods • Fish oils, salmon, sardines, herring • Fortified milk, breads, cereals • Animal livers, tuna fish, eggs, butter • Endogenous synthesis in the skin

18. Vitamin D: Function • Regulates absorption of and use of calcium and phosphorus • Necessary for normal calcification of bone and teeth

19. Vitamin D: Indications • Dietary supplement • Treatment of vitamin D deficiency • Treatment and correction of conditions related to long-term deficiency: rickets, tetany, osteomalacia • Prevention of osteoporosis

20. Vitamin D: Deficiency States • Vitamin D deficiency generally results from an inadequate dietary intake of vitamin D, or too little exposure to sunlight. • The vitamin D deficiency has also been found to occur in overcrowded urban areas. • The absence of sunlight or smog limitations inhibit the absorption of the D vitamin.

21. Vitamin D: Toxicity • Long-term ingestion of excessive amounts causes toxicity • Hypertension, weakness, fatigue, headache, many others • GI tract effects • CNS effects

22. Forms of Vitamin D • calcifediol • calcitriol • dihydrotachysterol • ergocalciferol

23. DIAGNOSIS • Serum 25(OH)D and PTH level. • Alkaline phosphatase level elevated. • Serum calcium and phosphate low. • Treatment • 250-1000microgram daily for 3-4 month, than decrease the dose 10-20 microgram or stop the therapy.

24. Vitamin E • Fat soluble • Tocopherols • Dietary plant sources • Fruits, grains, cereals, vegetables, oils, wheat germ • Animal sources • Eggs, chicken, meats, fish

25. Vitamin E: Function • Exact biologic function of vitamin E is unknown • Believed to act as an antioxidant

26. Vitamin E: Deficiencies • The Vitamin E deficiency is commonly found in infants and usually results from them having consumed formulas high in polyunsaturated fatty acids that are fortified with iron but not vitamin E. • Also, because vitamin E is a fat-soluble vitamin, a deficiency also develops in conditions associated with fat malabsorption, such as cystic fibrosis. 

27. Vitamin E: Indications • Dietary supplement • Antioxidant • Treatment of deficiency • Highest risk of deficiency in premature infants

28. Diagnosis • Plasma vitamin E levels can be measured; normal levels are 0.5–0.7 mg/dL or higher. Since vitamin E is normally transported in lipoproteins, the serum level should be interpreted in relation to circulating lipids.

29. Treatment • The potential antioxidant benefits of vitamin E can be achieved with supplements of 100–400 IU/d.

30. Vitamin K • Fat soluble • Three types: K1, K2, K3 • Dietary sources of K1 • Green leafy vegetables (cabbage, spinach), meats, milk • Vitamin K2 synthesized by intestinal flora

31. Vitamin K: Functions • Essential for synthesis of blood coagulation factors in the liver • Vitamin K–dependent clotting factors • II • VII • IX • X

32. Vitamin K: Indications • Dietary supplementation • Treatment of deficiency states (rare) • Antibiotic therapy • Newborn infants • Malabsorption • Reverse the effects of certain anticoagulants (warfarin)

33. Vitamin K: Deficiencies • The Vitamin K deficiency is commonly found among newborns within the first few days postpartum. Poor placental transfer of vitamin K to the infant and also inadequate production of vitamin K-producing intestinal flora is the main culprit. • The deficiency can also be caused by a prolonged use of drugs, such as antibiotics that destroy normal intestinal bacteria.  • Additionally, other causes are a decreased bile flow to the small intestine from bile duct obstruction, a malabsorption of vitamin K due to bowel resection, ulcerative colitis, or chronic hepatic disease. • The vitamin K deficiency seldom results from an insufficient dietary intake of it.

34. Laboratory Findings • The prothrombin time (PT) is prolonged to a greater extent than the PTT, and with mild vitamin K deficiency only the PT is defective. Fibrinogen level, thrombin time, and platelet count are not affected.

35. Treatment • Vitamin K deficiency responds rapidly to subcutaneous vitamin K, and a single dose of 15 mg will completely correct laboratory abnormalities in 12–24 hours.

36. Water-Soluble Vitamins • Vitamin B complex • thiamine (B1) – pyridoxine (B6) • riboflavin (B2) – folic acid (B9) • niacin (B3) – cyanocobalamin (B12) • pantothenic acid (B5) • Vitamin C • ascorbic acid

37. Water-Soluble Vitamins (cont'd) • Can dissolve in water • Excessive amounts excreted in the urine, not stored in the body • Toxic reactions are very rare

38. Vitamin B1 (Thiamine) • Water soluble • Food sources • Whole grains, liver, beans • Deficiencies • Beriberi • Wernicke’s encephalopathy

39. Vitamin B1 (Thiamine) Deficiencies • Beriberi • Brain lesions, polyneuropathy of peripheral nerves, serous effusions, cardiac anatomic changes • Wernicke’s encephalopathy • Cerebral beriberi

40. Vitamin B1 (Thiamine):Causes of Deficiencies • Poor diet • Extended fever • Hyperthyroidism • Liver disease • Alcoholism • Malabsorption • Pregnancy and breast-feeding

41. Vitamin B1 (Thiamine)Functions • Essential for: • Carbohydrate metabolism • Many metabolic pathways, including Krebs’ cycle • Maintains integrity of: • Peripheral nervous system • Cardiovascular system • GI tract

42. Diagnosis • Erythrocyte transketolase activity. Coefficient greater than 15-20% suggest thiamine deficiency. • Urinary thiamine excretion.

43. Vitamin B1 (Thiamine):Indications • Treatment of thiamine deficiency • Beriberi • Wernicke’s encephalopathy • Peripheral neuritis associated with pellagra • Metabolic disorders

44. Vitamin B1 (Thiamine):Indications (cont'd) • Dietary supplement • Malabsorption induced by alcoholism, cirrhosis, GI disease • Thiamine deficiency is treated with large parental doses of thiamine .50-100mg/d .All patients should simultaneously receive therapeutic doses of other water soluble vitamins Other uses

45. Vitamin B2 (Riboflavin) • Water soluble • Food sources • Leafy green vegetables • Eggs • Nuts • Meats • Yeast

46. Vitamin B2 (Riboflavin)Causes of Deficiency • Alcoholism is a major cause • Deficiency also caused by: • Intestinal malabsorption • Long-term infections • Liver disease • Malignancy • Probenecid therapy

47. Vitamin B2 (Riboflavin)Functions • Converted into enzymes essential for tissue respiration • Required to activate vitamin B6 (pyridoxine) • Converts tryptophan into niacin • Maintains erythrocyte integrity

48. Vitamin B2 (Riboflavin)Deficiency • Deficiency results in: • Cutaneous, oral, and corneal changes • Cheilosis • Seborrheic dermatitis • Keratitis

49. Vitamin B2 (Riboflavin):Indications • Dietary supplement • Treatment of deficiency • Microcytic anemia • Acne • Migraine headaches • Many other uses

50. Vitamin B2 (Riboflavin):Side Effects • No side effects or toxic effects • Large doses will discolor urine to a yellow-orange