Rate of Urinary Calcium Excretion Following Its Intravenous Administration as an Indicator of Bone Metabolism.

Abstract

In order to study the mechanism of Ca homeostasis serum levels and urinary excretions of Ca and P were measured in short intervals during and following admn. These data were also compared with metabolic data obtained in prolonged expts. Significant differences in the 24-hr.-Ca excretion rates were found between "normals" and groups of patients with increased tendancy to bone destruction and new bone formation,respectively. Spontaneous or therapeutically induced remissions could be detected promptly and early by decreased rates of urinary Ca excretions; progression of bone dissolution could be recognized by increased Ca excretion. A good correlation between these data and metabolic balance studies was found. The usefulness of this "tolerance test" in the study of bone diseases was discussed.