Treatment of renal bone disease with 1 alpha-hydroxylated derivatives of vitamin D3. Clinical, biochemical, radiographic and histological responses.

Forty patients with severe bone disease and chronic renal failure were treated with 1 alpha-hydroxycholecalciferol (1 alpha-OHD3) or 1,25-dihydroxycholecalciferol (1,25(OH)2D3) for 7--49 months (total = 738 patient months). There were symptomatic, biochemical and radiographic improvements in the majority of patients (greater than 70 per cent). Paired bone biopsies, taken before and during treatment in 26 patients, showed no change in bone matrix area, whereas matrix area decreased in a control group of 26 patients over the same period. There were small but consistent decreases in bone marrow fibrosis and in bone cell (osteoblast and osteoclast) counts in treated patients but not in controls. However, the proportion of patients who showed histological 'cure', in the sense of complete reversal of marrow fibrosis or excess osteoid was no greater in the treated than in the control group...