Long-term 1,25(OH)2 vitamin D therapy increases bone mineral density in osteopenic women. Comparison with the effect of plain vitamin D.

Background And Aims: Although the bone protective effect of vitamin D has been studied intensively, the usefulness of 1,25(OH)2D3 in treating osteoporosis is still questionable. The aim of the present prospective study was to evaluate the effect of a standard pharmacological dose of 1,25(OH)2D3 in postmenopausal unsubstituted women.

Methods: Our study group comprised 52 post-menopausal women with low normal or osteopenic values of bone mineral density (BMD). Thirty-two of them were treated with 1,25(OH)2D3 for 3 years. In parallel, another group of women was treated with cholecalciferol (n=20). Vitamin D adequacy before administration of 1,25(OH)2D3 and compliance with treatment were checked by serum PTH levels, which were assessed at the start and three times in the course of treatment.

Results: Increase in BMD at the spine at the end of the 1st, 2nd and 3rd years of treatment with 1,25(OH)2D3 (expressed as a percentage of the value before treatment) was higher, but did not significantly differ from the effect of plain vitamin D. A significant increase in BMD at the hip at the end of the 3rd (but not the 1st and 2nd) year of treatment with 1,25(OH)2D3 was found (p<0.05, compared with the effect of plain vitamin D). The protective effect of cholecalciferol was found only on spine but not hip BMD.

Conclusion: The study supports the hypothesis that long-term administration of 1,25(OH)2D3 is effective in treating low bone mass in postmenopausal women.