Long-term effectiveness of dietary iron and ascorbic acid in the prevention and cure of cadmium toxicity in rats.

The protective and curative effects of dietary iron and ascorbic acid on chronic (180 days) cadmium toxicity in rats were examined. Growth retardation and anemia were observed in rats fed a diet containing 50 ppm of cadmium for 180 days; during this period the contents of iron in the liver, kidney, spleen, testis, intestine, and tibia decreased and the zinc contents of the liver and kidney increased, but the calcium content of bone did not change. Addition of 400 ppm of iron and 1% of ascorbic acid to the cadmium-containing diet overcame the growth retardation and anemia due to cadmium toxicity and reduced the tissue levels of cadmium; however, it did not restore the zinc contents in the liver, kidney, and bone to normal. Similar effects were observed when these compounds were added to cadmium containing diet for 90 days after feeding the cadmium diet alone for 90 days. The glutamic-pyruvic transminase and glutamic-oxaloacetic transminase activities in the plasma of rats fed the cadmium diet increased significantly and these increases were prevented by supplementing the diet with iron and ascorbic acid. Glucose, urea, and alkaline phosphatase in the plasma and glycogen in the liver were not changed by feeding the cadmium diet for 180 days. These results indicate the long-term effectiveness of supplementing the diet with iron and ascorbic-acid for preventing and curing dietary cadmium toxicity in rats.