Serum 25-hydroxycholecalciferol in Greek uremics.

Using a simplified competitive protein-binding assay, we measured serum 25-hydroxycholecalciferol (25-OH-D3) in 52 patients with chronic renal failure and in 21 normal subjects. Of the patients with chronic renal failure, 21 were undergoing hemodialysis. Low serum levels of 25-OH-D3 were found in nondialysis patients and normal levels in the dialysis group.