[en] One of the major drawbacks of glucocorticoids long-term therapy is the occurrence of a severe osteoporosis characterized by fractures occurring at different sites, mainly at the level of trabecular bone. One of the major determinants of glucocorticoid-induced osteoporosis is a decrease in the intestinal absorption of calcium (Ca) leading to a secondary hyperparathyroidism. D-hormones have been shown to significantly improve Ca absorption in the gut and subsequently to decrease parathyroid hormone circulating levels, hence normalizing bone turnover. In a recent study evaluating 145 patients suffering from diseases requiring long-term treatment with high doses of corticosteroids, we have demonstrated a significant benefit of alphacalcidol (1 microg/day) over placebo in terms of changes in bone mineral density of the lumbar spine. These results are in accordance with studies showing better prevention of bone loss and vertebral fractures in cardiac transplant patients treated with alphacalcidol than those treated with etidronate. There is now a convergent body of evidence to suggest that alphacalcidol is a reasonable, safe, and effective option for the prevention of glucocorticoid-induced osteoporosis, provided that serum Ca is monitored on a regular basis.