Stress, Disease, and Vitamin E Requirements

Abstract

Vitamin E supplementation of several animal species has increased their immunocompetence and mitigated their decreased production brought on by stress. The dietary level of vitamin E needed for increasing either disease or stress resistance appears to be greater than that required for growth and reproduction. These latter two responses are generally used as the criteria for determining the requirement of a nutrient. In stress and disease there is an increase in production of glucocorticoids, epinephrine, eicosanoids, and phagocytic activity. Eicosanoid and corticoid synthesis and phagocytic respiratory burst are prominent producers of free radicals which challenge the animal's antioxidant systems. Due to a number of factors, the antioxidant vitamin E status of an animal may be marginal or deficient prior to and/or after stress and disease. Since vitamin E status is integral to an animal's health and productivity, then it is imperative to be able to determine this status. Current research with cattle suggests that serum vitamin E levels may not be useful in defining its adequacy, but the red blood cell vitamin E content may be.