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Vitamin E is a scientific puzzle because it is “a vitamin in search of a disease.” It was discovered in 1922 in the course of experiments on fertility in rats. It was named tocopherol, from the Greek “to bear young.” The results of other animal experiments have led vitamin E enthusiasts to claim benefits to humans ranging from increased sexual potency to prevention of heart disease and the cure of burns. But studies of vitamin E in humans have not substantiated these claims. Biochemically, vitamin E acts as an antioxidant, meaning that it prevents the oxidation of other substances where oxidation should not occur. It helps to maintain cell membranes and to protect vitamin A and polyunsaturated fatty acids as they are transported in the bloodstream. Vitamin E also helps keep red blood cells from being ruptured by oxidising agents, thereby leading to blood disorders. When vitamin E is added to oils, it prevents them from becoming rancid. Its role as a preservative and a protector of cell membranes has led to unsubstantiated claims that vitamin E can prevent the effects of ageing. Although vitamin E cosmetics and supplements are popular, there is no evidence that they prolong youth. The average Recommended Dietary Allowance for vitamin E as alpha-tocopherol equivalents is 10 milligrams for men and 8 for women. This amount is easily met by a balanced diet. If your diet contains considerable amounts of polyunsaturated fats, which accelerate the rate of oxidation of vitamin E, your vitamin E needs rise. However, since high polyunsaturated foods nearly always contain more vitamin E, supplemental vitamin E is unnecessary. Cases of vitamin E deficiency are almost nonexistent. They are difficult to create even in the laboratory. Premature infants on iron supplements sometimes need vitamin E medication to counteract the oxidant effect of the iron in their red blood cells. The use of vitamin E supplements is of highly questionable value. The toxic effects that have been reported tend to be mild and have included headache, fatigue, and nausea. As a fat-soluble vitamin, E is stored in the body. If people continue to use the great amounts of E that are popular today, some other harmful effects of excess doses may be further established. . There are many sources of vitamin E in the average diet. These include oils such as peanut, soy, and corn; margarine; whole-grain breads and cereals, especially wheat germ; leafy green vegetables; egg yolks; and liver. | 
