Probably the best known of all antioxidants is vitamin E (Tocopherol). The main compound, alpha-tocopherol, is an important antioxidant for cell membranes and fats. Vitamin E is an antioxidant derived from plants. It is actually a family of nutrients that includes tocopherol and tocotrienols, each with their own subfamilies of alpha, beta, gamma and delta substances. Unless your brand contains the full spectrum of these nutrients, you are not getting the full benefits of vitamin E.
IU stands for "International Units" and is usually used in the measurement of vitamin potency. There is no fixed definition for IU, as there is for grams or milligrams. The actual definition of IU depends upon the specific substance that you are measuring. For example, 1000 IU of Vitamin A has a different mass (weight) than 1000 IU of Vitamin E.
Vitamin E supplementation above 400 mg per day does not appear to lead to raised levels in the blood, so a daily supplementation of 300 milligrams is probably cost effective. The liver controls blood plasma vitamin E concentrations.
Most commercial vitamin E supplements do not contain the gamma form of the vitamin, depriving you of the full range of its antioxidant effects. The vitamin E you buy at the local pharmacy is mostly alpha tocopherol. The Academy of Sciences (NAS) has increased the RDA for vitamin E to 22 IU daily. There are different types of vitamin E. A number of studies comparing the effects of natural source E (labeled as d-alpha-tocopherol) with synthetic E (dl-alpha-tocopherol) show that the natural plant derived version is as much as two times as effective as the petroleum-based synthetic. Some benefits from vitamin E begin at about 400 IU daily, while some experts recommend twice that amount and the upper limit for daily intake of vitamin E, set by the National Academy of Sciences, is 1,000 mg. Amounts are usually stated in IU - international units.Some labels record amounts in milligrams. The equivalent of the 1,000 mg upper limit is 1,500 IU of natural vitamin E or 1,100 IU of the synthetic version.
Vitamin E aids in the prevention of cardiovascular disease and cancers of the lung, stomach, colon, breast and cervix. It also helps prevent sterility, improves circulation, prevents blood clots, prolongs life of red blood cells and strengthens capillary walls. Vit. E helps the body use vitamin A and maintains integrity of cell membranes. It contributes to healthy skin and hair. Vitamin E is an essential antioxidant, protecting healthy cells from destruction by free oxidising radicals.Vitamin E may prevent cataract formation.
Gamma E Tocopherol/ Tocotrienols
For full protection you need the full complement of tocopherol and tocotrienols, including alpha, beta, delta and gamma versions. TOCOTRIENOLS such as ALPHA-TOCOTRIENOL are 40-60 times more potent than ALPHA-TOCOPHEROL. Tocotrienols display anti-cancer activity. Tocotrienols directly inhibit growth of human breast cancer cells, with gamma- and delta being most inhibitory. They have been shown to inhibit proliferation of human breast cancer cells by 50%. This feature of tocotrienols goes on beyond Vitamin E (alpha-tocopherol), which did not demonstrate a similar effect (Timon, 2003).
Vitamin E serves the body in protecting membranes from toxic oxygen damage (oxidation). In contrast, vitamin C serves to protect the aqueous - or watery - regions of the cells from oxidation. The membranes that are most sensitive are the membranes of nerves and therefore the main symptom of vitamin E deficiency is damage to the nervous system. Vitamin E status is measured by assessment of the content of alpha-tocopherol in the blood plasma, using a method called high-pressure liquid chromatography. Blood plasma levels of alpha-tocopherol that are 5.0 mg/l or above indicate normal vitamin E status; levels below 5.0 mg/l indicate vitamin E deficiency.
Ageing and Vitamin E as an antioxidant
Vitamin E intake, from foods or supplements, is associated with less cognitive decline with age (Morris et al, 2002). There was little evidence of a similar association with vitamin C or carotene intake, showing the differing effects of antioxidants.
Lack of vitamin E causes reproductive problems - infertility, increased risk of miscarriage, etc. It also causes degeneration of the kidneys and general wasting symptoms. Vitamin E deficiency is a very rare problem that results in damage to nerves. Vitamin E deficiency in humans results in ataxia (poor muscle co-ordination with shaky movements), decreased sensation to vibration, lack of reflexes, and paralysis of eye muscles. One particularly severe symptom of vitamin E deficiency is the inability to walk. Fat-soluble vitamins, vitamins A, D, E and K, are stored in the fat tissues of the body for a few days to up to six months. If you get too much of a fat-soluble vitamin, it can be stored in your liver.
It is almost impossible to overdose on vitamin E. Large scale studies have shown that people can take up to 10 grams a day for extended periods without adverse effects, though some individuals find that doses in excess of 1 gram a day can cause stomach problems. After eaten and absorbed, vitamins are distributed to the target tissues and enter the cells. Any surplus is used to maintain the optimum level in the blood and the rest is either stored (fat soluble) or excreted (most water soluble)
Excess Vitamin A is stored in the liver to a max reserve of 500,000 IU
Excess Vitamin D is stored in the liver
Excess Vitamin E is stored in the fatty tissues with a normal pool of 5,000 IU (roughly 3000 mg)
Excess Vitamin K is stored in the liver
Vitamin E is known to be essential for muscle development and for preventing the red blood cells from breaking down. It also believed to be important in maintaining reproductive health, though it is not yet clear by what mechanism. It protects against miscarriage by promoting the healthy development of the foetus. It also has a vital role as an antioxidant, protecting cells from attack by free radicals and peroxides. The more research is carried out, the more beneficial results seem to be attributable to vitamin E. It can help to prevent cancers developing, when taken in combination with selenium, and seems to reduce the unwanted side effects of radiotherapy and chemotherapy. At high doses (800mg a day) it acts as an anticoagulant, preventing the formation of clots and thromboses, and has been found to be beneficial in correcting some cardiovascular disorders. It helps strengthen the immune system so increasing resistance to viral and bacterial infection at in doses of between 5 - 20 mg per kilo of body weight (350 - 1400 mg for someone weighing 70kg). For cataract prevention, daily doses between 300 - 400 mg are effective, particularly combined with vitamin C and beta-carotene. Recent studies suggest that, in common with other anti-oxidants, it may have a contribution to make in preventing the onset of Parkinson's disease, or slowing the deterioration it causes: doses of 400 - 3200 mg combined with 300 mg of vitamin C seem beneficial. Scandinavian research indicates that a 400 mg supplement of vitamin E with selenium can give a significant boost to the physical and psychological health of elderly people.
Antioxidants, such as vitamin E and vitamin C, help fight against cell damage and slow ageing in the body. High intake of vitamin E and C may also reduce the risk of Alzheimer's disease, a degenerative disease that leads to loss of physical and mental function
Good sources of vitamin E include wheatgerm, soya, corn and peanut oils, margarine, raw nuts and seeds, eggs, butter, yams, liver and some green leafy vegetables. It is, however, quite easy to destroy vitamin E by freezing, processing, preserving and simple contact with the air.
Vitamin E Content of Selected Foods
as Alpha-Tocopherol Equivalents (mg) (1 mg = 1 alpha TE)
Wheat germ oil
Sweet Potato (Raw)
Hellman's Sandwich spread
Mazola Corn Oil
Macaroni (enriched & cooked)
Green Cabbage (raw)
Mustard Greens (raw)
Always consult your doctor. This site is for information purposes and does not prescribe products. Confirm all details with a specialist (see disclaimer).