[Frontiers in vitamin D; basic research and clinical application. Inhibitory effects of eldecalcitol, an active vitamin D derivative, on bone resorption in vivo].

Eldecalcitol is a new vitamin D(3) derivative recently approved for the treatment of osteoporosis in Japan. Previous studies showed that daily administration of eldecalcitol increased bone mineral density (BMD) by suppressing bone resorption in animals and in patients with osteoporosis. We examined how eldecalcitol suppresses bone resorption in vivo . Daily administration of eldecalcitol into mice did not affect properties of osteoclast precursors, but suppressed RANKL expression in bone. These results suggest that daily administration of eldecalcitol increase BMD by suppressing RANKL expression in bone.