title: Dietary vitamin E requirement for optimum immune responses in the rat.
abstract: Supplementation of diets with vitamin E has been shown to enhance immune responses in numerous animal models. However, these experiments have not investigated the dietary requirement of vitamin E for optimal T- and B-lymphocyte mitogen responses and compared this directly with the requirement for growth, maintenance of spleen-body weight ratios, platelet count as well as prevention of myopathy and red blood cell lysis. We have found that male weanling rats maintain normal rate of growth and spleen-body weight ratio when fed purified diets containing 7.5 mg/kg vitamin E. A level of 15 mg/kg was adequate to prevent myopathy, and 50 mg/kg was necessary for the prevention of red blood cell hemolysis. The dietary requirement for optimum T- and B-lymphocyte responses to mitogens was greater than 50 mg/kg and was significantly correlated with plasma vitamin E levels over a range of 0.04-18 micrograms/ml. Thus, the requirement for this index of immune system activity was higher than for the other functional parameters of vitamin E adequacy measured. Therefore, the immune system responds to changes in dietary vitamin E well before there are signs of frank vitamin deficiency.
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D004032:Diet; D006461:Hemolysis; D007109:Immunity; D008213:Lymphocyte Activation; D008297:Male; D008934:Mitogens / Q000494:pharmacology; D009751:Nutritional Requirements; D010976:Platelet Count; D011770:Pyruvate Kinase / Q000097:blood; D051381:Rats; D011918:Rats, Inbred SHR; D013601:T-Lymphocytes / Q000276:immunology; D014810:Vitamin E / Q000008:administration & dosage*; D014811:Vitamin E Deficiency / Q000276:immunology
chemical_list: D008934:Mitogens; D014810:Vitamin E; D011770:Pyruvate Kinase