Vitamin E. Polarised light micrograph of crystals of vitamin E (tocopherol). This is an essential vitamin for fertility and reproduction. Its structure is that of the tocopherols, methylated derivatives of tocol. The alpha form of tocopherol is properly known as 5,7,8-trimethyltocol; this alpha form has the strongest vitamin E activity. Vitamin E is widely distributed in vegetable lipids and the body fat in animals; the richest sources are seed embryos and their oils, and green leaves. The vitamin protects unsaturated fats from oxidation. As tocopherol is widely distributed in the diet, vitamin E deficiency is rare. Magnification: x26 at 6x7cm size. x45 at 4x5"~PORTRAIT"