A simplified technique for the measurement of intestinal absorption of calcium in the dog: effects of PO4 depletion and 25(OH)D3 in uremia.

A simplified method is described for the measurement of calcium absorption in the dog. This method uses 45Ca and takes less than 8 h to perform. Calcium absorption was measured in normal and uremic dogs on different intakes of calcium and phosphorus and compared to the results obtained in the same animal maintained on the same diet by another method using 47Ca and a double dilution procedure. The correlation coefficient between the two methods was 0.99 (P < 0.001). The advantages of the simplified method are discussed.