Twelve patients on continuous ambulatory peritoneal dialysis (CAPD) were studied in order to evaluate the progression of renal osteodystrophy (ROD). All patients received doses of 0.01 ‐ 0.02 μg/kg of 1 alpha vitamin D3(1α ‐ D3) and 0.1 ‐ 0.15 g/kg of calcium carbonate for 12 ‐ 18 months. Serum total protein, total calcium (Ca), creatinine, inorganic phosphate alkaline phosphatase (ALP), and n‐terminal parathyroid hormone were measured regularly. The radiological bone appearance for ROD or rickets and the height standard deviation score were compared between the outset and the end of this study. An increase of Ca values and a decrease of ALP values correlated with a suppression of hyperparathyroidism, and the hyperphosphatemia was controlled in the majority of our patients throughout this study. Two patients had ROD and rickets at the outset of this study, and all patients but one had neither ROD nor rickets at the end of this study. Growth retardation improved or remained stable in 10 patients. Our results indicate that adequate doses of 1α ‐ D3and calcium carbonate are effective in the prevention of ROD and rickets in pa