Effect of Dietary Calcium and Phosphorus on 54 Mn Metabolism Following Single Tracer Intraperitoneal and Oral Doses in Rats 1

Summary

The effects of dietary calcium [0.1% (low) or 0.6% (normal)] and phosphorus [0.4% (normal) or 0.9% (high)] on ⁵⁴Mn metabolism were determined following single ip or oral dosing in weanling rats. Rats receiving the low calcium diet excreted much more ⁵⁴Mn from both ip and oral doses via feces and urine, and their tissues retained much less. Within each dietary calcium level, urinary excretion of ip administered ⁵⁴Mn was far less on the high phosphorus diet. With orally administered ⁵⁴Mn, high dietary phosphorus increased ⁵⁴Mn tissue concentrations. These results show that low dietary calcium has a major effect on manganese metabolism at the tissue level as well as within the gut.