Response of uremic osteoid to vitamin D.

Three patients with nutritional osteomalacia and three with the osteomalacia of chronic renal failure were treated with small doses of vitamin D for 4 to 10 months. The plasma concentration of 25-OH vitamin D rose to and remained within the normal range throughout the study. There was similar increase in the extent of calcification front in the osteoid lamellae lying immediately adjacent to calcified bone in the two groups of patients. The associated histologic appearances of hyperparathyroidism improved in the patients with nutritional osteomalacia but did not change or became worse in the patients with the osteomalacia of chronic renal failure.