An evaluation of 1 alpha-hydroxy-and 1,25-dihydroxyvitamin D3 in the treatment of renal bone disease.

40 patients with bone disease due to chronic renal failure have been treated with 1 alpha-hydroxyvitamin D3 or 1,25-dihydroxyvitamin D3 for a total of 750 patient-months. Both compounds were very effective in relieving bone pain and muscle weakness, and in reversing the radiographic and biochemical indices of disturbed skeletal metabolism. Their effects as judged from bone biopsies were, however, less complete, and histological improvement occurred only in a few patients. Patients with the combination of osteitis fibrosa and osteomalacia responded better than patients with either abnormality alone. Factors of importance in adversely influencing the outcome of treatment included a high pre-treatment level of calcium or immunoreactive parathyroid hormone, and a failure to augment secretion of calcitonin during treatment. It is concluded that a major therapeutic advantage of 1 alpha-OHD3 and 1,25(OH)2D3 over previously available forms of vitamin D is their rapid onset and reversal of action. These drugs do not invariably reverse bone disease and may give rise to unwanted effects. They should therefore only be used with adequate clinical, biochemical and radiographic supervision. They should not be used indiscriminately in all renal patients.