Vitamin E, also known as tocopherol, is a fat-soluble antioxidant that protects cell membranes and fatty acids from oxidative damage. It is absorbed along with fat in the small intestine and transported throughout the body via lipoproteins. Vitamin E functions to prevent lipid peroxidation, protect cellular integrity, and support reproductive health. The recommended daily intake is 10-15 mg for adults, and deficiency can cause hemolytic anemia and neurological issues. Good dietary sources include vegetable oils, meat, eggs and dairy.

1. VITAMIN E
BY
Dr SAI PRIYANKA NERUSU

2. INTRODUCTION
• Vitamin E (tocopherol) is a naturally occurring antioxidant. It is essential for normal
reproduction hence known as anti-sterility vitamin.
• Evans and his associates (1936) isolated the compounds of vitamin E activity and named
them as tocopherols
• Evans and his associates (1936) isolated the compounds of vitamin E activity and named
them as tocopherols
• About eight
• Tocopherols (vitamin E vitamers) have been identified Alpha, Beta, Gamma, Delta, etc.
• Among these, Alpha-tocopherol is the most active.
• The antioxidant property is due to the hydroxyl group of chromane ring.

3. ABSORPTION, TRANSPORT AND
STORAGE
• Vitamin E is absorbed along with fat in the small
intestine.
• Bile salts are necessary for the absorption.
• In the liver, it is incorporated into lipoproteins (VLDL
and LDL) and transported.
• Vitamin E is stored in adipose tissue, liver and muscle.
• The normal plasma level of tocopherol is less than 1
mg/dl.

4. Biochemical functions
• Most of the functions of vitamin E are related to its antioxidant property.
• It prevents the nonenzymatic 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.
• 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.
• Vitamin E acts as a scavenger and gets itself oxidized (to quinone form)
by free radicals (R) and spares PUFA

5. BIOCHEMICAL FUNCTIONS OF VITAMIN E
• Vitamin E is essential for the membrane structure
and integrity of the cell, hence it is regarded as a
membrane antioxidant.
• 2. It prevents the peroxidation of polyunsaturated fatty
acids in various tissues and membranes. It protects
RBC from hemolysis by oxidizing agents (e.g.
H2O2).
• 3. It is closely associated with reproductive
functions and prevents sterility. Vitamin E preserves
and maintains germinal epithelium of gonads for
proper reproductive function.

6. BIOCHEMICAL FUNCTIONS OF VITAMIN E
4.It increases the synthesis of heme by enhancing the activity of enzymes Delta-
aminolevulinic acid (ALA) synthase and ALA dehydratase.
5. It is required for cellular respiration through electron transport chain (believed to
stabilize coenzyme Q).
6. Vitamin E prevents the oxidation of vitamin A and carotenes.
7. It is required for proper storage of creatine in skeletal muscle.
8. Vitamin E is needed for optimal absorption of amino acids from the intestine.
9. It is involved in proper synthesis of nucleic acids.
10. Vitamin E protects liver from being damaged by toxic compounds such as carbon
tetrachloride.
11. It works in association with vitamins A, C and Beta -carotene, to delay the onset of
cataract.

7. BIOCHEMICAL FUNCTIONS OF VITAMIN E
• Vitamin E has been recommended for the prevention of
chronic diseases such as cancer and heart diseases
• It is believed that vitamin E prevents the oxidation of LDL.
(Note : The oxidized LDL have been implicated to promote
heart diseases.)
Vitamin E and selenium
• The element selenium is found in the enzyme glutathione
peroxidase that destroys free radicals
• Thus, Se is also involved in antioxidant functions like vitamin
E, and both of them act synergistically.

8. RECOMMENDED DIETARY ALLOWANCE (RDA)
• Intake of vitamin E is directly related to the
consumption of polyunsaturated fatty acids (PUFA)
i.e., requirement increases with increased intake of
PUFA.
• A daily consumption of about 10 mg (15 IU) of alpha-
tocopherol for man and 8 mg (12 IU) for woman is
recommended.
• One mg of alpha-tocopherol is equal to 1.5 IU.
• Vitamin E supplemented diet is advised for pregnant
and lactating women.

9. 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, butter and
eggs.

10. 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 in central
nervous system.
• Severe symptoms of vitamin E deficiency are not
seen in humans except increased fragility of
erythrocytes and minor neurological symptoms.

11. TOXICITY OF VITAMIN E
•Among the fat soluble vitamins (A, D,
E, K), vitamin E is the least toxic.
• No toxic effect has been reported
even after ingestion of 300 mg/ day
for 23 years.

12. THANK YOU