The available data with regard to the use of calciferol, dihydrotachysterol, and calcifediol in the management of renal insufficiency are reviewed. Very limited data are available with regard to calciferol therapy; with the advent of more active metabolites, the use of calciferol is not warranted. Dihydrotachysterol seems to be effective in the treatment of renal patients with osteitis fibrosa; its low cost makes therapy with this compound a reasonable alternative, although it should not be used in the treatment of patients with liver disease. Calcifediol seems to be effective in patients with osteitis fibrosa; however, limited data on histologic characteristics of bone are available. Detailed prospective studies are necessary to establish the therapeutic benefit of calcifediol.