The role of vitamins in modulating disease resistance

Many of the metabolic incursions resulting from stress and oxidative damage are detrimental to disease resistance. Vitamins A, E, and C and carotenoids are able to protect cells from free radical oxidation, reduce the detrimental effects of certain eicosanoids, and enhance humoral and cellular immune responses in disease. The regulation of cell differentiation by vitamin A in maintaining an epithelial barrier to pathogen entry and the differentiation of precursor cells to functional lymphocytes by 1,25-dihydroxycholecalciferol are essential to disease resistance. Nutritionists must redefine the levels of vitamins necessary to maximize health-supportive systems. The animal's metabolism must constantly be adjusting to its environmental stress or disease and may require increased vitamins.