CADMIUM ACCUMULATION, ZINC STATUS, AND MINERAL BIOAVAILABILITY OF GROWING RATS FED DIETS HIGH IN ZINC WITH INCREASING AMOUNTS OF PHYTIC ACID

Five groups of individually housed albino rats (it = 7, initial averag e weight = 48 g) were fed diets based on egg albumen and cornstarch (b asal diet 8.2 g Ca, 6.0 g P, 0.7 g Mg, 225 mg Zn, 150 mg Fe, 60 mg Mn, 8 mg Cu, and 5 mg Cd) over a 4-wk period. Group I (control) was fed t he basal diet free of phytic acid (PA). In groups II, III, IV, and V, cornstarch was replaced by 3.5, 7.0, 10.5, and 14.0 g sodium phytate/k g diet, respectively. Daily gain, feed efficiency, Zn status (Zn in pl asma, femur, testes, liver and kidneys, activity of the plasma alkalin e phosphatase) and apparent absorption of Zn, Fe, Cu, and Mn remained unchanged by the different dietary treatments. PA decreased apparent M g absorption significantly and apparent absorption of Ca in tendency. Increasing the amount of phytate caused a corresponding enhancement of amount of the digestible P. Cd accumulation in the liver was not sign ificantly altered, and kidney Cd accumulation slightly increased owing to PA. In conclusion, it was shown that under conditions of high diet ary Zn, PA had only little effect on the carryover of Cd in growing ra ts.