Treatment of osteoporosis of ageing with 1alpha-hydroxycholecalciferol.

Seven patients with osteoporosis of ageing were treated with synthetic 1alpha-hydroxycholecalciferol (1alpha-H.C.C.) for 3-4 months. The compound was given at a daily oral dose of 2 mug together with an oral supplement of 1 g of calcium. Clinically there was a striking improvement in the patients' physical fitness. Increased bone formation and mineralisation were seen on iliac-crest bone biopsy, and this was supported by an increased osteoblastic activity demonstrated by histochemical measurement of alkaline-phosphatase activity. Bone histology furthermore showed a reduced bone resorption, which was supported by a reduced urinary excretion of total hydroxyproline. Photon absorptiometry of the forearm accorded with the histological findings, showing a significant increase in the bone mineral content. Serum-calcium rose in all patients, one developing a severe transitory hypercalcaemia. The urinary excretion of calcium and magnesium increased significantly. The serum concentrations of 25-hydroxycholecalciferol and parathyroid hormone were not significantly affected by the treatment. It is concluded that 1alpha-H.C.C. is an effective tool in the treatment of senile osteoporosis.