Effect of Ascorbic Acid on Cadmium Toxicity in the Young Coturnix

Abstract

This study was designed to evaluate the effects of supplements of individual dietary components in altering the toxicity of dietary cadmium. Day-old coturnix (Japanese quail) were fed 75 mg Cd/kg of an adequate purified diet for 2- or 4-week periods. Cadmium produced moderate growth retardation, severe anemia, decreased ash content of the tibia, and deviations from the normal concentrations of zinc, iron, cadmium, copper, and calcium in one or more of the cells or tissues assayed (erythrocyte, liver, kidney, and tibia). Dietary supplements of zinc, iron(III), copper, and L-cysteine·HCl and injected ascorbic acid produced slight to moderate protection against cadmium-induced anemia, whereas iron(II), ascorbic acid, and D-isoascorbic acid had marked effects in preventing the anemia, growth retardation, poor bone mineralization, and perturbations in elemental concentrations of tissues. Chromium, cobalt, selenium, nickel, molybdenum, and pteroylglutamic acid had no effects. Cadmium did not affect the total ascorbate content of the liver. Removal of dietary ethoxyquin did not affect the toxicity of cadmium or the protective effects of ascorbic acid. Initiation of ascorbic acid feeding at 2 weeks was beneficial to birds fed cadmium throughout the 4-week experiment. Under the conditions of these experiments, cadmium produced a functional iron deficiency and less clear-cut effects on zinc function. It appears that a primary effect of cadmium was to prevent absorption of dietary iron(III).