Effect of low dose 1 alpha-hydroxycholecalciferol on glomerular filtration rate in moderate renal failure.

Serial measurements of 51Cr edetic acid clearance were made over a period of one year in two groups of 8 children, in a double blind trial of 1 alpha-hydroxycholecalciferol (10 ng/kg/day) and calciferol (670 ng/kg/day). Glomerular filtration rate (GFR) at the beginning of the trial was 20-50 ml/min/1.73 m2; it rose in the children given 1 alpha-hydroxycholecalciferol (group A) after 6 months but was not appreciably different from the pretreatment value after 12 months. The GFR in the children given calciferol (group B) showed no significant difference at 6 or 12 months. Parathyroid hormone values fell markedly in group A after 6 months but not in group B. Quantitative bone histology improved considerably in group A but not in group B at 12 months. Low dose 1 alpha-hydroxycholecalciferol may be used effectively for renal osteodystrophy in children with moderate but stable renal failure without jeopardising renal function.