VITAMIN E: Antisterility factor, antioxidant, and…?

Professor H. M. Evans, when making a study of the reproductive capacity of rats at the University of California in 1922, found that animals given a diet containing all the then known vitamins failed to produce normal litters. This observation indicated that another vitamin was required for fertility and subsequently led to the recognition of vitamin E. The vitamin was known to be present in lettuce and wheat germ, since when either of these were added to the rats' feed their fertility was restored. Subsequently, in 1936, by a lengthy procedure for concentrating the vitamin, Evans was successful in isolating the pure substance from wheat germ oil. It was identified as an alcohol with the chemical formula G29H50O2 and found to be fat soluble. At the suggestion of Professor G. Calhoun, Evans introduced the name “a‐toco‐pherol” for the pure compound (from the Greek tokos = childbirth, phero = to bear, and “‐ol” indicating that the substance is an alcohol).