Vitamin e

Chemistry of Vitamin E, Biochemical role of Vitamin E, Recommended dietary Allowances, Dietary sources of Vitamin E, Deficiency symptoms of vitamin E, Hypervitaminosis of vitamin E, Toxicity of Vitamin E,

1. Chemistry, Biochemical Role, RDA, Deficiency diseases of Vitamin E Jasmine Juliet .R Biotechnology Department Agricultural college and Research & Institute Madurai .

2. Vitamin E - Introduction Vitamin E is a fat soluble Vitamin. It was recognized in 1922. Fat soluble dietary constituent was found to be essential for the prevention of foetal death and sterility in rats. Vitamin E was called tocopherol from the Greek word tokes and pherein , meaning to bring forth children.

3. Vitamin E - Chemistry Vitamin E ( tocopherol ) is a naturally occurring antioxidant . It is essential for normal reproduction in many animals, hence known as anti-sterility vitamin. Vitamin E is the name given to a group of tocopherols and tocotrienols . About eight tocopherols have been identified - α, β, γ, δ etc. Among these α- tocopherol is the most active .

4. Vitamin D - Biochemical functions I. Most of the functions of vitamin E are related to its antioxidant property . It prevents the non-enzymatic oxidations of various cell components (e.g. unsaturated fatty acids) by molecular oxygen and free radicals such as superoxide (O2-) and Hydrogen peroxide (H2O2). The element selenium helps in these functions.

5. Vitamin D - Biochemical functions II. Vitamin E is lipophilic in character and is found in association with lipoproteins, fat deposits and cellular membranes. It protects the polyunsaturated fatty acids (PUFA ) from peroxidation reactions. III. Vitamin E acts as a scavenger and gets itself oxidized (to quinone form) by free radicals (R ) and spares PUFA.

6. Vitamin D - Biochemical functions The biochemical functions of vitamin E, related either directly or indirectly to its antioxidant property , are given: IV. Vitamin E is essential for the membrane structure and integrity of the cell, hence it is regarded as a membrane antioxidant. It prevents the peroxidation of polyunsaturated fatty acids in various tissues and membranes. V. It protects RBC from hemolysis by oxidizing agents (e.g.H2O2).

7. Vitamin D - Biochemical functions VI. It is closely associated with reproductive functions and prevents sterility. Vitamin E preserves and maintains germinal epithelium of gonads for proper reproductive function. VII. Vitamin E protects liver from being damaged by toxic compounds such as carbon tetrachloride. VIII. It works in association with vitamins A, C, and β-carotene, to delay the onset of cataract.

8. Other roles of Vitamin E Vitamin E may also play important roles in other biological processes. They include: Structural role in the maintenance of cell membrane integrity. Anti-inflammatory function. DNA synthesis . Stimulation of immune response . Protecting Vitamin A, C and unsaturated fatty acids.

9. Recommended dietary allowance (RDA) A daily consumption of about 10mg (15 IU) of α- tocopherol for man and 8mg (12 IU) for woman is recommended. One mg of α- tocopherol is equal to 1.5 IU. Vitamin E supplemented diet is advised for pregnant and lactating women.

10. Dietary sources Many vegetable oils are rich sources of vitamin E. Wheat germ oil, Cotton seed oil, peanut oil, corn oil, and sunflower oil are the good sources of this vitamin. It is also present in meat, milk, and eggs .

11. Deficiency symptoms The symptoms of vitamin E deficiency vary from one animal species to another. In many animals, the deficiency is: associated with sterility, degenerative changes in muscle , megaloblastic anaemia and changes central nervous system.

12. Toxicity of vitamin E Among the fat soluble vitamins (A, D, E, K), Vitamin E is the least toxic. Acute and chronic toxicities are very rare. Relatively few side effects are seen in humans even at intakes as high as 3200IU/day. Some cases have shown that it may cause: B reast soreness, E motional disorders, M uscular weakness and G astrointestinal disorders.

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