2. Water Soluble Vitamins

3. Cobalamin
Vitamin B12

4. Introduction
Vitamin B12 includes a group of cobalt, containing compounds known as cobalamins.
The major forms found in plasma and tissue include
Methyl cobalamin
Adenolylcobalmin and
Hydroxycobalamin.
All of these forms are biologically active.

6. Food sources Vitamin B12 occurs only in animal sources.
The richest sources include
Lamb and beef kidney
Lamb and calf beef
Liver and brain.
Other good sources include
Heart, egg yolk and variety of sea foods

7. Stability and solubility
Stable to heat in aq.medium
Only slightly soluble in water
Little lost during cooking

8. Functions Vitamin B12 is required by all cells of the body, especially
Gastro-intestinal tract
Bone marrow and
Nervous system.
Within bone marrow, it is involved in conversion of ribose nucleotides into deoxyribose nucleotides

9. Functions (Contd.) An essential step in DNA synthesis.
If DNA is not synthesized in enough quantities, large RBC’s (macrocytes) are released into the blood.

10. Absorption and Metabolism
Vitamin B12 is absorbed through receptor sites in the ileum, mediated by intrinsic factor which is produced by glands in stomach.
Vitamin is then transported across the intestinal cell and then into blood stream.
Vitamin B12 is normally stored in liver for 3 to 5 years.

11. Recommended Dietary Allowances
The RDA of 3.0 g of Vitamin B12 for adults allows for maintenance of adequate nutrition and substantial reserve body pool.

12. Effects of Deficiency
Deficiency of Vitamin B12 is usually caused by defect in absorption rather than by dietary factors
When intrinsic factor is not produced, Vit B12 is not absorbed.

13. Effects of Deficiency (Contd.)
As a result, bone marrow cannot produced mature red blood cells and so releases the large, immature precursor (macrocytes) into blood stream instead.
The symptoms of megalotblastic anemia include pallor, weight loss, anorexia, glossitis, sprue and in advanced stages, degeneration of spinal cord.

14. Toxic Effect
No toxic effect in humans

15. Toxic Effects Generally considered to be nontoxic
gastro-intestinal symptoms may be experienced by some individuals

16. Folic Acid (Folacin)
Vitamin B10

17. Folacin is generic name for folic acid and related compounds.
The chemical term for folacin or folic acid is pteroylglutamic acid.

18. STRUTURE
Folic acid is a conjugated molecule consisting of a pteridine ring
structure linked to para-aminobenzoic acid (PABA) that forms
pteroic acid. Folic acid itself is then generated through the
conjugation of glutamic acid residues to pteroic acid

19. Folic Acid positions 7 & 8 carry hydrogens,in Dihydrofolate (DHF)
positions 5-8 carry hydrogens, in Tetrahydrofolate (THF)

20. All forms of folacin are equally utilized in the body
More folacin is excreted in urine and feces than is accounted for in the diet, which indicates that this vitamin is also synthesized by intestinal flora
Most of folacin is stored in liver
Folic acid is converted to its biologically active form folinic acid in the liver

21. Recommended dietary allowance
RDA for adults in 400 g of folacin daily

22. Deficiency Diseases
Folate deficiency results in complications nearly identical to those of vitamin B12 deficiency.
The most pronounced effect of folate deficiency on cellular processes is upon DNA synthesis.
The result is megaloblastic anemia as for vitamin B12 deficiency.

23. Megaloblastic anemia

24. Deficiency Diseases
The inability to synthesize DNA during erythrocyte maturation leads to abnormally large erythrocytes termed macrocytic anemia.
Folate deficiencies are rare due to the adequate presence of folate in food.
Poor dietary habits as those of chronic alcoholics can lead to folate deficiency.

25. Deficiency Diseases
The predominant causes of folate deficiency in non-alcoholics are impaired absorption or metabolism or an increased demand for the vitamin.
Certain drugs such as anticonvulsants and oral contraceptives can impair the absorption of folate.
Anticonvulsants also increase the rate of folate metabolism.

26. Deficiency Diseases Folic acid appears to reduce the risk of stroke
Low blood levels of folic acid are associated with increased risk of cancer. (Breast, pancreas and colon)
Damage to DNA caused by folate deficiency may be the reason.

27. Prevention of Neural Tube Defect leading to spina bifida at the very early stage of pregnancy

28. INCREASED REQUIREMENT
The predominant condition requiring an increase in the daily intake of folate is, pregnancy.
pregnancy and infancy are both characterized by increased number of rapidly proliferating cells present in the blood.
The need for folate will nearly double by the third trimester of pregnancy.

29. Possible Toxic Effect Risk from Folic acid Toxicity is very low.
Tolerable upper intake level for adult is 1 mg/day.
Upper intake level is 800 ug/day for pregnant and lactating women if less than 18 years of age.
Supplemental level should not increase than the upper level to prevent folic acid from masking symptoms of Vitamin B-12

30. VITAMIN - C

31. Ascorbic Acid Ascorbic acid is commonly known as vitamin C
Lactone Ring

32. Vitamin C exists in two forms,
Ascorbic acid Most vitamin C is present in this form
Dehydroascobic acid.
Both are equally well utilized by humans

33. Functions
This vitamin is essential for hydroxylation of amino acids Proline and Lysine to hydroxyproline and hydroxylysine respectively
Important components of collagen , found in cartilage, bone, dentin and vascular epithelium.
Vitamin C is important in wound healing

34. Functions 2. Other functions include:
Synthesis of epinephrine and antiinflamatory steroid by adrenal gland
White blood cell functions phagocytosis
Folic acid metabolism –Redues folic acid to THFA and helps in maturation of RBCs

35. Functions Tryptophan metabolism to serotonin by hydroxylation
Tyrosine metabolism to homogenestic acid by oxidation
Iron metabolism facilitates the conversion of ferric to ferrous state which is preferentially absorbed

36. Functions Reconversion of methaemoglobin to hemoglobin
Helps in the synthesis of bile acid from cholesterol
Antioxidant,may prevents cancer
Catract formation risk is reduced

37. Absorption and Metabolism
Vitamin C is quickly absorbed form gastro-intestinal tract and distributed in various tissues of body
Highest concentration are found in adrenal gland, with appreciable amounts in kidneys, spleen, liver, pancreas, thymus and pituitary
Once the tissues are saturated, is excreted by the kidneys

38. Recommended Dietary Allowances
60 mg/day is required by both males and females
Children have higher vitamin C requirement than do adults, on a weight basis

39. Food Sources Vitamin C is present in variety of fruits and vegetables
Fresh, frozen or raw fruits and vegetables are best sources. citrus fruits, cabbage, spinach etc.
Vitamin C is easily destroyed by prolonged cooking at high temperatures due to oxidation

40. Deficiency manifestations
Deficiency of vitamin C results in faulty/ defective formation of collagenous intracellular substances.

41. Clinical Manifestations
Joint pains
Poor growth
Anemia
Increased susceptibility to infections and
Poor wound healing

42. Advanced form of vitamin C deficiency results in scurvy
Manifested clinically as
Easy bruising,
Bleeding gums and
Hemorrhages

43. Toxic Effects Generally considered to be nontoxic
gastro-intestinal symptoms may be experienced by some individuals