Correlation between skeletal calcium mass and muscle mass in man.

The measurements of total body potassium (TBK) and calcium (TBCa) were made on 317 subjects by the techniques of whole-body counting and total-body neutron activation analysis (TBNAA), respectively. The TBK/TBCa ratios are constant for normals over the age range studied. The males have more cellular mass (TBK) per unit skeletal mass (TBCa) than the females, as indicated by their respective TBK/TBCa ratios, 0.122 +/- 0.008 (1 SD), and 0.100 +/- 0.007 (1 SD). In general, patients with various metabolic disorders tend to follow the physiological trend found in the normals. In a number of metabolic disorders, the loss of TBK was usually approximately 60% of that of the TBCa when expressed in terms of the predicted normal values. This suggests that the mechanism causing the loss of calcium in physiological and altered metabolic states simultaneously involves both the skeleton and its associated musculature.