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 gamma-tocopherol being
between 1 and 20% 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 and E309).
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
E308 is an antioxidant for polyunsaturated fatty acids as well
as a vitamin. Less effective than alpha-tocopherol (E306
and E307) in animals but not 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.