Vitamin E has a wide margin of safety in animals, and toxicity of this vitamin has not been demonstrated in ruminants. Compared with vitamin A and vitamn D, both acute and chronic studies in animals have shown that with vitamin E, the toxicity risk is relatively lower, but excessively high levels can result in undesirable effects. Hypervitaminosis E studies in rats, chicks and humans indicate maximum tolerable levels in the range of 1,000 to 2,000 IU per kg (455 to 910 IU per lb) of diet (NRC, 1987).
