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. 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.

4. 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.

9. 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.

10. 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.

11. 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).

12. 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.

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

14. 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.

15. 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.

17. 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.

19. 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:
 Breast soreness,
Emotional disorders,
Muscular weakness and
Gastrointestinal disorders.