Alfacalcidol is an analogue of Vitamin D and a potent inhibitor of bone resorption [1].
Alfacalcidol has been revealed to play a part in bone and mineral homeostasis via binding to the VDR (vitamin D receptor) in calcium-related target organs, such as intestine, bone, kidney and parathyroid gland. In addition, in a high bone-turnover state after OVX, Alfacalcidol has been reported to inhibit osteoclastic bone resorption at pharmacological doses that do not cause hypercalcemia. Apart from these, Alfacalcidol has shown the stimulative effect to the bone formation. Furthermore, Alfacalcidol has been found to enhance bone mass and bone strength at given serum and urinary calcium levels in the OVX model.
References:
[1] Shiraishi A1, Takeda S, Masaki T, Higuchi Y, Uchiyama Y, Kubodera N, Sato K, Ikeda K, Nakamura T, Matsumoto T, Ogata E. Alfacalcidol inhibits bone resorption and stimulates formation in an ovariectomized rat model of osteoporosis: distinct actions from estrogen. J Bone Miner Res. 2000 Apr;15(4):770-9.
