This 7-page document discusses vitamin E. It begins by defining vitamins and describing vitamin E's structure and functions. Vitamin E is a fat-soluble antioxidant that protects cells from damage and may help prevent diseases. The document outlines the biosynthesis pathway of vitamin E and its mechanism of action as an antioxidant, for immunomodulation, and antiplatelet effects. Potential advantages are described, but high doses of vitamin E supplements are linked to increased health risks. Rare diseases can result from a vitamin E deficiency.

1. Page 1 of 7
December 18, 2013
ASSIGNMENT ON
VITAMIN E
SUBMITTED TO:
Dr. SUMAIRA RASUL
SUBMITTED BY:
HINA MUSHTAQ….. ROLL # 02
ZAHRA NAZ……….. ROLL # 04
TOOBA MAQBOOL.. ROLL # 20
FAIZA SHAUKAT...... ROLL # 23
STUDY COURSE:
BIOCHEMISTRY-I
STUDY PROGRAMME:
BS- BIOTECHNOLOGY-3rd SEMESTER
INSTITUTE OF MOLECULAR BIOLOGY AND
BIOTECHNOLOGY, B.Z.U., MULTAN.

2. “Vitamins are organic compounds which are needed in small quantities to sustain
life. We get vitamins from food, because the human body either does not produce
enough of them or none at all.”
Page 2 of 7
VITAMINS
A vitamin is one of a group of organic substances, present in minute amounts in natural
foodstuffs that are essential to normal metabolism; insufficient amounts in the diet may cause
deficiency diseases.
Put simply, a vitamin is both:
 An organic compound (contains carbon).
 An essential nutrient the body cannot produce enough of on its own, so it has to get it (tiny
amounts) from food.
13 different types of vitamins have been discovered till now.
Fat soluble and water soluble vitamins
Fat-soluble vitamins are stored in the fat tissues of our bodies, as well as the liver. Fat-soluble
vitamins are easier to store than water-soluble ones, and can stay in the body as
reserves for days, some of them for months.
Fat-soluble vitamins are absorbed through the intestinal tract with the help of fats (lipids).
Water-soluble vitamins do not get stored in the body for long - they soon get expelled
through urine.
Water-soluble vitamins need to be replaced more often than fat-soluble ones.
Vitamins A, D, E and K are fat-soluble.
Vitamins C and all the B vitamins are water-soluble.

3. Page 3 of 7
Vitamin E
INTRODUCTION
Vitamin E is a collection of eight different, but closely related, compounds. These are alpha-,
beta, gamma, and delta-tocopherol and alpha, beta, gamma, and delta-to cotrienol. Each of
these compounds has a different degree of activity in humans. Alpha-tocopherol is the most
active form. Vitamin E in dietary supplements is usually synthetic compound called alpha-tocopherol
acetate. Synthetic alpha-tocopherol is sometimes labeled dl-alpha-tocopherol.
Description
Vitamin E is a name for eight antioxidants, of which the only one active in the human body is
referred to as α-tocopherol. It is a potent antioxidant; numerous studies have pointed to a
protective effect against arterial plaque buildup and cancer. It is helpful in the relief of
intermittent calf pain and in preventing problems peculiar to premature infants. In large doses,
it has an anticoagulant effect. The recommended daily dietary allowance for adults is 10 mg
(tocopherol equivalents) for men and 8 mg for women, but nutritionists and physicians
sometimes recommend higher doses for disease prevention.
STRUCTURE OF VITAMIN E
Vitamin E is the generic term used for all of the compounds in this group. The vitamin can
exist as two types of structures: the tocopherol and tocotrienol structures. Both structures are
similar except the tocotrienol structure has double bonds on the isoprenoid units. There are
many derivatives of these structures due to the different substituent possible on the aromatic
ring at positions 5, 6, 7, and 8.

4. Notice that there are three chiral centers, at positions 2', 4', and 8', in the phenyl tail. There is
thus the possibility of eight stereo isomers but have an unsaturated tail.
Page 4 of 7
FUNCTIONS OF VITAMIN E
Vitamin E has many therapeutic properties.
 It can be used topically and ingested. It is available in a capsule for easier ingestion or in oil.
Vitamin E oil can be swallowed or applied to the skin.
 Vitamin E is a powerful antioxidant that is essential for several basic bodily functions.
 Vitamin E is believed to help delay or prevent heart disease and some types of cancer.
 Vitamin E as an antioxidant helps protect the body against stroke, cataracts, cancer, heart
disease, and even the signs of aging.
 Vitamin E actually protects the walls of the arteries. It prevents bad cholesterol (LDL) from
being oxidized, preventing clogged arteries.
 Vitamin E can also prevent platelets from clumping together and forming blood clots. This can
help prevent a stroke or heart attack.
 Vitamin E can also help prevent or fight cancer. It protects the cell's DNA from damage that
can cause the cells to turn cancerous. It can actually reduce the rate of growth for tumors, at the
same time enhancing the immune system to fight cancer.
 Vitamin E capsules can even help enhance the action of insulin. This improves blood glucose
function in diabetes.
 It is also pivotal in the proper function of the brain. It protects the myelin sheaths that surround
neurons in the brain. This can help prevent degeneration during the normal aging process. It
may also help prevent Alzheimer's disease.
 Vitamin E can also help make the hair healthier and increase growth. It can also be used in
conditioners to improve the look of damaged hair.

5. Page 5 of 7
BIOSYNTHETIC PATHWAY OF VITAMIN E

6. Page 6 of 7
Action mechanism of VITAMIN E
Vitamin E appears to act through several mechanisms; it functions as an antioxidant, and it acts
through immunomodulation, as well as through an antiplatelet effect.
As anti oxidant
Vitamin E appears to act within membranes by preventing the propagated oxidation of
saturated fatty acids. Oxidized LDL particles are taken up more readily by macrophages than
by native LDLs, which lead to the formation of cholesterol-laden foam cells found in the fatty
streak of early atherosclerosis. It is hypothesized that vitamin E reduces atherosclerosis and
subsequent coronary heart disease by preventing oxidative changes to LDLs.
As Immunomodulation
Vitamin E appears to enhance lymphocyte proliferation, decrease the production of
immunosuppressive prostaglandin E2, and decrease levels of immunosuppressive serum lipid
peroxides.
Antiplatelet effect
Vitamin E has been demonstrated to inhibit platelet adhesion, as measured by a laminar flow
chamber when blood from patients who have taken vitamin E supplements is tested. This effect
appears to be related to a reduced development of pseudopodia, which normally occurs upon
platelet activation. It may be related to changes in fatty acylation of platelet structural proteins.
Although vitamin E inhibits platelet aggregation in vitro, its effect in vivo has not been
consistent.
ADVANTAGES OF VITAMIN E
 Vitamin E is a key for strong immunity and healthy skin and eyes.
 In recent years, vitamin E supplements have become popular as antioxidants. These are
substances that protect cells from damage.
 Many people use vitamin E supplements in the hopes that the vitamin's antioxidant properties
will prevent or treat disease. But studies of vitamin E for preventing cancer, heart disease,
diabetes, Alzheimer's disease, cataracts, and many other conditions have been inconclusive.

7. Page 7 of 7
DISADVANTAGES OF VITAMIN E
 The risks and benefits of taking vitamin E are still unclear. Long-term use (over 10 years) of
vitamin E has been linked to an increase in stroke.
 In addition, an analysis of clinical trials found patients who took either synthetic vitamin E or
natural vitamin E in doses of 400 IU per day -- or higher -- had an increased risk of dying from
all causes, which seems to increase even more at higher doses.
 Cardiovascular studies also suggest that patients with diabetes or cardiovascular disease who
take natural vitamin E at 400 IU per day have an increased risk of heart failure and heart
failure-related hospitalization.
DISEASES DUE TO DEFICIENCY OF VITAMIN E
Vitamin E deficiency rarely causes but these diseases are very much fatal.
 Cystic fibrosis
 Abetalipoproteinemia
 Chronic cholestatic hepatobiliary disease
 Short-bowel syndrome
 Isolated vitamin E deficiency syndrome
Intramuscular administration is necessary when the deficiency results from a low
concentration of bile salts in the lumen of the small intestine, because these patients are
unable to absorb oral preparations.
Treatment, which may include oral or parenteral vitamin supplementation, must be designed
to address the underlying cause of the deficiency.