Retention of cadmium in organs of the rat after a single dose of labeled cadmium-3-phytate

Because of the low safety factor estimated for the normal content of Cd in human foods, it is important to establish the influence of food constituents such as phytate on the bioavailability of this toxic metal. We studied the retention of radioactive¹⁰⁹Cd administered to rats as a chloride or a phytate in a single dose by stomach tube. The animals were fed either a normal rat chow containing 0.29% of phytate or a low phytate diet containing less than 0.1% phytate. Highly elevated levels of¹⁰⁹Cd were found only in the animals that were supplied with¹⁰⁹Cd as a chloride and had been fed the low phytate diet. In the animals supplied with¹⁰⁹Cd as a phytate, which had also received the low phytate diet, the levels of¹⁰⁹Cd in the intestine were as high as those in the group mentioned before, but the retentions in all other tissues resembled those of the respective groups fed the normal chow. The findings indicate that phytate is responsible for a considerable decrease in the intestinal absorption of Cd. Furthermore, it appears to exert an influence on the kinetics of Cd retention in the intestine.