What is the use and function of VITAMIN E ?
Vitamin E is an essential fat-soluble vitamin that includes eight naturally
occurring compounds in two classes designated as tocopherols and tocotrienols.
Each of these compounds exhibits different biological activities. d-a-Tocopherol has the highest biological activity and is
the most widely available form of vitamin E in food. The other isomers (b, g, d), some of which are more abundant in a typical
Western diet, are less biologically active than d-
a-tocopherol. The commercially available synthetic
forms of vitamin E are comprised of approximately an equal mixture of eight
stereoisomeric forms of a-tocopherol. For practical purposes, 1 international
unit (IU) of vitamin E is referred to as 1 mg of the synthetic form, racemic
a-tocopherol acetate, and the natural form of d-a-tocopherol has a biopotency
of vitamin E equal to 1.49 IU. The most widely accepted biological function
of vitamin E is related to its antioxidant properties. Vitamin E is the most
effective chain-breaking lipid-soluble antioxidant in the biological membrane,
where it contributes to membrane stability. It protects critical cellular structures
against damage from oxygen free radicals and reactive products of lipid peroxidation.
Vitamin E is an important anti-oxidant. It acts as a free radical scavenger
to prevent the byproducts of chemical-cell interaction to cause cell damage.
Free radicals are likely responsible for all or most of the degenerative diseases
e.g. arthritis, heart disease, cancer, senility etc. The absorption or scavenging
of free radicals would protect our cells from this type of injury. Other free
radical scavengers include zinc, vitamin C, and selenium. Studies have reported
vitamin E to protect against some of the toxicities of ionizing radiation. Vitamin
E may help to decrease the toxicity of certain chemotherapy drugs.
Adriamycin is an important anti-cancer drug with potential major toxicity
to the heart. The use of 1000 to 2,000 units of vitamin E per day may help to
decrease this toxicity.
Vitamin E may decrease some of the harmful effects of solar radiation on
the skin. As cited above it works well in conjunction with beta-carotene. Vitamin
E appears to have stabilizing effect on the vascular system and is useful in
decreasing menopausal and premenstrual symptoms. It is useful in decreasing
leg cramps occurring especially at night.
Vitamin E can be used in lotions or creams to protect the skin or to treat
for burns. It is also helpful to treat burns secondary to radiation therapy.
I have also used it with good results in-patients with dermatitis resulting
from poor blood circulation i.e. stasis dermatitis. It is commonly prescribed
for topical use in pregnant women to prevent stretch marks on the abdomen. More
recently it has been used to prevent or treat mucositis resulting from chemotherapy.
The main signs of deficiency are reproductive failure, nutritional "muscular
dystrophy", hemolytic anemia, and neurological and immunological abnormalities.
Vitamin E deficiency occurs rarely in humans, having been reported in only two
situations: premature infants with very low birth weight and patients who fail
to absorb fat.
The Recommended Dietary Allowance(RDA) for vitamin E is based primarily on customary
intakes from U.S. food sources. The current RDA for males is 10 mg and 8 mg
for females. However, the requirement for vitamin E increases with higher intakes
of polyunsaturated fatty acids (PUFA). The recommended ratio of E/PUFA is 0.4
mg d- a-tocopherol per gram of PUFA. In defining
the ideal intake, factors to consider are: intake of other antioxidants, age,
environmental pollutants, and physical activity.
Vegetables and seed oils including soybean, safflower, and corn; sunflower seeds,
nuts; whole grains; and wheat germ are the main sources of the tocopherols.
Leafy vegetables also supply an appreciable amount of this nutrient. However,
animal products and most fruits and vegetables are generally poor sources. Absorption
of vitamin E is dependent upon the digestion and absorption of fat. Free tocopherols
are absorbed by a non-saturable passive process into the lymphatic circulation
along with fat. About 45% of an ordinary dose is absorbed into the lymph.
Vitamin E is relatively safe compared to the fat-soluble vitamins. Few side
effects from high intakes of this vitamin have been reported, even at doses
as high as 3200 mg daily. However, high vitamin E supplementation may be contraindicated
when a coagulation defect is present due to vitamin K deficiency or in individuals
receiving anticoagulant drugs.
Vitamin E has been shown to influence signal transduction pathways. This effect,
however, may not be mediated through its antioxidant properties. Evidence from
in vitro studies shows that vitamin E influences expression of adhesion molecules
on endothelial cells and monocyte adhesion to endothelial cells. Vitamin E supplementation
significantly improved immune response in healthy elderly. High serum vitamin
E levels have been associated with reduced risk for coronary heart disease in
men and women.
For further information:
Meydani, M. (1995) Vitamin E. Lancet 345: 170-175
Meydani, S.N., Wu, D., Santos, M.S. & Hayek, M.G. (1995) Antioxidants and
immune response in aged persons: Overview of present evidence. Am. J. Clin.
Nutr.; 62: 1463S-1462S
Miller, R.D. & Hayes, K.C. (1982) Vitamin excess and toxicity. In: Nutritional
Toxicology (Hathcock, J.N., ed.) vol. 1, pp. 81-133. Academic Press, New York,
Minerals:VITAMIN C: This vitamin is important for tissue healing.
Minerals: Formula Plus
Minerals:Why Minerals before Vitamins ?
Read what the US Senate knew in 1936 read Senate Document #264-COLLOIDAL MINERALS
CAN MAKE A MINERAL Colloidal Minerals:
Minerals: What is the use and function of Beta-Carotene
Minerals: Total Toddy
important B COMPLEX ?
REQUEST YOUR FREE EAGLE PRODUCT INFORMATION PACK: INFOPACK@eagle-min.com