Alfacalcidol versus plain vitamin D in the treatment of glucocorticoid/inflammation-induced osteoporosis.

Treatment with plain vitamin D is a nutritional substitute, while the application of alfacalcidol is an active hormonal therapy. Due to strong feedback regulation, plain vitamin D is not activated in the kidney in vitamin-replete patients, while alfacalcidol, having been hydroxylated at position 1, bypasses regulation and increases available amounts of active D-hormone in different target tissues. Nevertheless, a majority of physicians still prescribe plain vitamin D plus calcium as a first-step prevention or even as therapy for glucocorticoid (GC) induced osteoporosis.