The effect of cadmium on vitamin A metabolism

It has been reported that a number of toxic agents impair normal vitamin A (VA) metabolism (A. D. Bruin, 1976, In Biochemical Toxicology of Environmental Agents, pp. 937–980. Elsevier, Amsterdam). A study was conducted to explore the effect of cadmium chloride (CdCl₂) on VA metabolism. Female rats of the Wistar strain were given drinking water containing 50 ppm of cadmium (Cd) for 237 days. Cadmium ingestion did not affect the food intake and body weight, but a significant decrease in serum VA was observed, concurrently with an increase in liver VA. In studying ingestion of tritiated VA alcohol (all trans-[15-³H]retinol), it was found that the absorption of VA alcohol from the intestine, the release of newly absorbed VA from the liver to serum, and the conversion of VA to water-soluble metabolites in the liver were not influenced by Cd. These findings suggest that Cd interfered with the release of VA, especially stored VA, to serum.