VITAMIN E

a fat-soluble compound (tocopherol) found principally in certain plant oils and the leaves of green vegetables. Wheat-germ oil is a particularly rich source. Vitamin E, first recognized in 1922, was first obtained in a pure form in 1936; it was identified chemically in 1938. A number of similar compounds having vitamin E activity and called tocopherols have been isolated. Vitamin E acts as an inhibitor of oxidation processes in body tissues. It protects unsaturated fats in the body from oxidation by peroxides and other free radicals. The possibility that vitamin E may help prolong an active life-span by slowing the rate of oxidative destruction of biological membranes is under study. The tocopherols are used commercially as antioxidants to retard the rancidification of fats, especially vegetable oils. For the effects of depriving animals of this vitamin, see vitamin E deficiency.