Vitamin E, known as the anti-sterility vitamin - from the Greek
tokos (child) and pherein (bear), is fat-soluble and is a mixture
of alpha-, beta-, gamma- and delta- tocopherols. Although eight
chemically similar substances have Vitamin E activity, alpha-
tocopherol is the most active of these (100%) with delta-tocopherol
being 1% Vitamin E activity.
Found in most foods, it is abundant in, amongst other things,
whole grain cereals, corn and cottonseed oils, egg yolks, meat
and milk. (See also E306, E307
It is essential to the life of red blood cells and helps the
supply of oxygen to the heart and muscles. Its requirement is
increased by high intakes of polyunsaturated fats but, as the
body stores about a year's supply, Vitamin E deficiency that
produces signs and symptoms is rare. It is possible that generous
intakes protect cell membranes from oxidation damage and consequent
E309 is an antioxidant for polyunsaturated fatty acids as well
as a vitamin. Reported to be the most effective antioxidant
of all the tocopherols in non-biological matter. It also protects
other nutrients, such as Vitamin A, from oxidation but is largely
destroyed by freezing.
Commercially it can be produced from cottonseed, maize, rice
germ, soya been oil, wheat germ, or green leaves and may, therefore,
come from Genetically Modified sources.