Studies on the metabolism of calcium and phosphorus and on the availability of these elements from milk and from an inorganic source

SOME time ago experiments were reported from this laboratory [Henry & Kon, 1937, 1] on the availability to rats of Ca and P in raw and pasteurized milks. While no difference was found in this respect between the two milks two rather puzzling observations were made. In the first place, though the rats received only 60 to 70 % of the Ca and P normally retained by rats of their age on an adequate diet, they utilized only some 80 % of their intake of these minerals. Secondly, 90 % of the excreted Ca was found in the urine, a result hardly to be expected as it is usually believed that Ca is largely excreted in the faeces.