A fat-soluble vitamin: vitamin E

A third fat-soluble vitamin or group of vitamins is vitamin E, or perhaps one should say the vitamins E. There are very many substances with vitamin E activity, but the term vitamin E is restricted to the tocopherols. (The word tocopherol is derived from Greek words signifying child birth.) There are 4 tocopherols now known: alpha, beta, gamma and delta tocopherol. The formula for alpha tocopherol is:

Beta and gamma tocopherol have 1 less methyl group than alpha tocopherol and delta tocopherol has 2 less methyl groups.

Vitamin E is necessary for the reproduction of the rat and other mammals and birds. If the male rat is fed a diet lacking in vitamin E, the germ cells in the testis degenerate. In the absence of vitamin E, the female rat cannot give birth to its young; these degenerate and are resorbed. In some cases, muscular atrophy follows lack of vitamin E in the diet.

The mechanism whereby vitamin E functions in the body is still unknown." In the first place it may act as part of an enzyme system, and to this action its effect in preventing degeneration of muscle may be due. Secondly, the tocopherols exert another, less specific function in that they tend to prevent excessive oxidation. Thus, for example, they tend to preserve vitamin A and they may also prevent the necessary unsaturated fats from being oxidized.