Vitamin E Deficiency in Chicks I. The Effects of Dietary Supplements on Plasma Tocopherol Levels and Vitamin E Deficiency Symptoms

Abstract

The present investigation was undertaken to determine the effects of a water-miscible multiple vitamin preparation, iron, and other substances on the occurrence of vitamin E deficiency symptoms and the plasma tocopherol levels of experimental animals, and to see whether vitamin E-deficient animals developed ocular abnormalities similar to retrolental fibroplasia. The chief symptom of vitamin E deficiency observed in these experiments was encephalomalacia; cases of exudative diathesis and of gizzard necrosis were also observed. No ocular abnormalities were found. Deficiency symptoms occurred only when cod liver oil was a constituent of the diet. The plasma tocopherol levels of chicks fed the α-tocopherol-supplemented diets were lowered by the administration of a water-miscible multiple vitamin preparation, cod liver oil, or crystalline vitamin A. Iron supplements, in either the ferric or ferrous form, had no effect. Chicks showing plasma tocopherol levels of approximately 1.0 mg% or more never developed symptoms. Chicks having plasma tocopherol levels of approximately 0.5 mg% or less developed symptoms only when fed certain diets. Chicks did not develop symptoms when fed the vitamin E-deficient basal diet supplemented with the multi-vitamin preparation, or when fed the natural diet supplemented with 5% cod liver oil. In both these groups, cod liver oil was present in the diet and the plasma tocopherol levels were as low as those of chicks receiving the vitamin E-deficient basal diet. The absence of symptoms in these two groups indicates that there are substances other than vitamin E, present in the natural diet and in the multi-vitamin preparation, which protect chicks from vitamin E deficiency symptoms. The protective factor in the multi-vitamin preparation was found to be ascorbic acid.