Effect of calcium supplementation on bone mass in patients operated on for hyperparathyroidism

Photon absorptiometry was used to measure bone mass in the lumbar vertebrae, proximal femur, mid-radius and distal radius in eight pairs of closely matched female patients with primary hyperparathyroidism before, and 1, 3 and 6 months after operation. One of each pair was randomised to receive 3 g of oral calcium supplementation/day for three months postoperatively, and the other to serve as a control. After successful operations on the parathyroids, the bone mass in the lumbar vertebrae, proximal femur, and distal radius increased by roughly 7% during the first six months in both the treated and the control patients. This study shows that oral calcium supplementation after operation for hyperparathyroidism does not result in any additional increase in bone mass beyond the effect that is caused by the operation.