Postmenopausal osteoporosis: no effect of three years treatment with 1,25-dihydroxycholecalciferol.

The therapeutic effect of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) in postmenopausal osteoporosis was tested in a single blind, randomized prospective study. Thirty-nine women, 50-65 years of age, were treated for three years with 0.5 microgram 1,25(OH)2D3 daily. In a control group, 37 women were given 400 IU vitamin D3 daily. There was no significant difference in annual bone loss from the distal or proximal forearm between the groups. New vertebral fractures were evaluated, and in the treatment group, the annual increase in vertebral fractures was 0.18 +/- 0.387 and in the control group 0.13 +/- 0.330. New long bone fractures were 7 and 5, respectively. None of the observed differences were statistically significant. In the 1,25(OH)2D3 group, 28% had to reduce the dose because of slight hypercalcaemia. We conclude that 1,25(OH)2D3 as used in this study is not effective in the treatment of osteoporosis.