Effect of 1alpha-hydroxycholecalciferol in senile osteoporosis and in bone loss following prednisone treatment.

Synthetic 1alpha-hydroxycholecalciferol, a potent vitamin D analogue, was given daily together with calcium to seven patients with senile osteoporosis and to three patients with prednisone-induced bone loss. Quantitative bone histology indicated increased formation and mineralization after three months of treatment. The bone resorption was reduced, a finding supported by a decrease in the urinary hydroxyproline excretion. Photon absorptiometry of the forearm showed a significant rise in the bone mineral content, in accordance with the histological findings. Serum calcium rose in all patients and severe hypercalcemia developed in one case. Urinary excretion of calcium and magnesium increased significantly. The findings indicate that treatment with 1alpha-hydroxycholecalciferol may be useful in osteoporosis due to aging or following corticosteroid administration. The patients must be carefully followed up because of the risk of hypercalcemia.