Calcium and calcitriol therapy in osteoporotic postmenopausal women with impaired calcium absorption

The effects of oral calcitriol (0.25 and 0.50 μg/d), together with calcium (1 g/d), on calcium absorption and bone resorption were measured in postmenopausal osteoporotic women with calcium malabsorption. Radiocalcium absorption was significantly improved and urinary hydroxyproline/creatinine excretion significantly reduced on both doses, but the higher dose caused an unacceptable incidence of hypercalcemia. In 49 patients treated for an average of 15 months with the lower dose, there was a nonsignificant gain in forearm bone mass of 0.4 ± 0.3 mg/cm/mo ( per annum) compared with a significant decrease in 17 untreated patients of 3.8 ± 1.3 mg/cm/mo (≈5% per annum).