Vitamin E - Benefits, Deficiency Symptoms And Food Sources
Alternative name :: Anti-aging vitamin and Anti-oxidant vitamin
In 1922, Evans and Bishop discovered another fat-soluble factor and named it vitamin E. This factor was found to be essential for reproduction in rats. Although the same functions have not been proven in humans, the vitamin was named tocopherol (vitamin E) from the Greek tokos meaning 'childbirth', pherein meaning 'to bear' and ol signifying an alcohol.
Vitamin E comprises a group of compounds known as tocopherols and tocotrienols. These are of different types - alpha, beta, gamma and delta. Of these, alpha-tocopherol is the most active and is also the form which is most abundant in foods.
Being fat-soluble in nature, vitamin E and other fat-soluble vitamins are absorbed along with fat in the presence of bile acids. Small amounts of vitamin E are present in all body tissues, but the bulk is stored in muscle, liver, and adipose tissue.
It is now recognized that vitamin E plays a, fundamental role in the normal metabolism of all cells. Its deficiency can affect several organ systems. Its functions are related to several other nutrients. Together with some other nutrients, it plays an important role in the defense mechanisms of the body.
Vitamin E is stable to high temperature and acids but it gets oxidized easily in the presence of oxygen. Thus, it acts as an antioxidant. Vitamin E is soluble in fats and organic solvents but insoluble in water. Normal cooking temperatures are not destructive but freezing, processing and frying result in vitamin E losses.
Functions of vitamin E
Vitamin E is a fat-soluble antioxidant and one of body's prime defenders against oxidation. It protects the lipids and other vulnerable components of the body cells and their membranes from oxidation.
Its function as an antioxidant is particularly important in tissues rich in polyunsaturated fatty acids (PUFA) and tissues which are in constant contact with oxygen, like lungs. Vitamin E is particularly effective in preventing the oxidation of PUFA, other lipids, as well as related compounds such as vitamin A. Thus, vitamin E protects the lipids of the membranes from oxidative damage duo to highly reactive oxygen species and other free radicals. Vitamin E reduces the harmful free radicals to harmless metabolites. This process is called 'free radical scavenging'.
Vitamin E protects the unsaturated lipids and vitamin A because it can accept oxygen and get oxidized itself, thereby acting as an antioxidant. It thus exerts a sparing action on vitamin A by preventing its oxidation. Vitamin E also protects fats and oils from oxidation and rancidity, thereby acting as a preservative.
Recent researches have shown that vitamin E may play a role in reducing the risk of heart disease by protecting LDL (low density lipoprotein) cholesterol against oxidation. Vitamin E exerts an especially important antioxidant effect in the lungs, where the exposure of the cells to oxygen is maximal. Vitamin E's antioxidant property protects not only the lung tissues but also the red blood cells and white blood cells that pass through the lungs. Vitamin E also protects the lungs against air pollutants.
In its antioxidant function, vitamin E acts synergistically with selenium (a trace element) to protect the cells from the damaging effects of oxygen species and free radicals. In fact, selenium and vitamin E both have a sparing effect on each other, and also reduce the body's requirement for each other.
The antioxidant function of vitamin E and other nutrients protects our body against conditions related to oxidative stress, such as aging, air pollution, arthritis, cancer, cardiovascular diseases, diabetes and infections. A lot of research is being conducted on the role of vitamin E in the above mentioned areas.
False hopes :- When vitamin E was discovered in 1922, it was termed as the 'antisterility factor' because of its role in fertility and preventing abortions in rats. However, any of these functions have not yet been proven in humans. It is, therefore, a misnomer to call vitamin E the 'reproduction vitamin'. Till date, it has not been proven that vitamin E can improve sexual potency, prevent baldness, improve athletic performance or increase life-span in humans. Nonetheless, vitamin E's role as an antioxidant in protecting the membranes in our bodies from damage, is extremely important.
Benefits of Vitamin E
Vitamin E is an antioxidant that is important in the prevention of cancer and cardiovascular disease. It improves circulation, is necessary for tissue repair, and is useful in treating premenstrual syndrome and fibrocystic disease of the breast. Specifically, vitamin E may help to:
Daily allowances of vitamin E
The minimum Recommended Dosage Allowance of Vitamin E are :-
Rich sources of vitamin E
Vitamin E is found in the following food sources: coldpressed vegetable oils, especially wheat germ, sunflower seeds, safflower, and soya bean oils. Eggs, butter, raw or sprouted seeds, and grains - especially whole wheat - are moderately good sources. Meats, fruits, and green leafy vegetables provide small quantities of this vitamin. Herbs that contain vitamin E include alfalfa, bladderwrack, dandelion, dong quai, flaxseed, nettle, oat straw, raspberry leaf, and rose hips.
Deficiency of vitamin E
In human beings, vitamin E deficiency is rare. Deficiency is usually seen in patients suffering from fat malabsorption since vitamin E, like other fat-soluble vitamins, is absorbed along with fats. Such patients have multiple vitamin deficiencies. Vitamin E deficiency is also seen in premature infants since they have poor vitamin E stores in their body.
Deficiency of Vitamin E is not common, and the symptoms not very clear cut, but may include fatigue, inflamed varicose veins, wounds healing slowly, premature aging and sub-fertility. When Vitamin E is in short supply symptoms may include acne, anemia, muscle disease, dementia, cancers, gallstones, shortened red blood cell life span, spontaneous abortion (miscarriage), and uterine degeneration.
Vitamin E toxicity
Vitamin E is one of the least toxic vitamins. Both humans and animals can safely consume relatively high doses without incurring any side effects. Human beings can tolerate doses, which are 100 times the nutritional requirement. At very high doses, vitamin E can interfere with the utilization of other fat-soluble vitamins, especially vitamin K. The fat-soluble vitamin K plays an important role in blood clotting. An imbalance in the ratio of vitamin E and vitamin K can interfere with blood clotting, eventually leading to haemorrhage.
The best recommendation is to use pulyunsaturated oils that are rich in vitamin E along with a well-balanced diet without use of mega doses or supplements. Vitamin E may have a role in preventing degenerative disorders such as cardiovascular disorders and cancer. These claims are not fully proven. Therapeutic supplements of vitamin E should be used for patients suffering from fat malabsorption.
(c) Health-care-clinic.org All rights reserved
Disclaimer: Health-care-clinic.org website is designed for educational purposes only. It is not intended to treat, diagnose, cure, or prevent any disease. Always take the advice of professional health care for specific medical advice, diagnoses, and treatment. We will not be liable for any complications, or other medical accidents arising from the use of any information on this web site. Please note that medical information is constantly changing. Therefore some information may be out of date.