Abstract
Although hypocalcemia has been recognized for decades in patients with nephrotic syndrome (NS), it was initially simply related to the reduction in the protein-bound calcium fraction as a result of the heavy proteinuria (1, 2). Thus, true hypocalcemia (low ionized calcium) was assumed to be absent in NS and the observed low serum total calcium concentration was not considered as having clinical significance. However, with the advent of calcium specific electrodes, direct measurements of serum ionized calcium became available in patients with NS.