Tocopherol form affects vitamin E

VITAMIN E functions as abiological antioxidant,preventing the oxidation of unsaturated lipid materials within cellular and subcellular membranes by neutralizing production of free radicals. It is a critically important nutrient for all horses, but is especially important for exercise, reproduction and for horses at risk of certain neurological diseases. Mayhew et al. (1987) found that supplementing mares with 1,500 IU of vitamin E per day decreased the incidence of equine degenerative myeloencephalopathy (EDM) from 40 to 10 % in foals born to these mares. Blythe and Craig (1993) found that young foals showing signs of incoordination and ataxia appeared normal by two years of age when supplemented with 6,000 IU of vitamin E. Vitamin E can be obtained from natural or synthetic sources, but the chemical structure of each is different. Natural vitamin E is composed of one isomer (d-alpha-tocopherol [RRR alpha-tocopherol]), while synthetic vitamin E is a mixture of eight isomers (dl-alpha-tocopherol [all-rac-alpha-tocopherol]), only one (12.5%) of which is identical to the natural isomer. For vitamin E to be included in equine feeds without a loss of potency, esters are added to form stable acetates. In order for vitamin E acetates to be utilized in the body, two steps are necessary: The ester has to be removed, and the alpha-tocopherol has to be made water soluble by the action of bile salts in a process known as micellization. Kentucky Equine Research has conducted three studies to assess the effects of different forms of vitamin E on vitamin E status. Vitamin E aNAT> SYN (P < 0.05). Sample tim