Serum ionized calcium in nephrotic syndrome.

Serum ionized calcium was measured in 12 patients with nephrotic syndrome and 14 nephrotic patients during clinical remission. All subjects had normal creatinine clearance and were not receiving treatment at the time of study. The mean serum ionized calcium values of the two groups of patients, 1-08 +/- 0-10 (SD) mmol/l ultrafiltrate and 1-21 +/- 0-10 (SD) mmol/l ultrafiltrate respectively, are significantly lower than the normal mean (1-28 +/- 0-06 (SD) mmol/l ultrafiltrate). The mean values of the patients in remission is, however, significantly higher (P less than 0-005) than that of the patients with manifest nephrotic syndrome. Elevated serum complexed calcium, and high serum protein-bound calcium in relation to serum albumin, were encountered, being more apparent in patients with overt nephrotic syndrome.