The incidence of constipation and exanthem was lower in eldecalcitol than in alfacalcidol group (Table 2). There was no significant difference in the incidence of any other adverse events between the eldecalcitol and alfacalcidol groups. Analyses of the seven pre-specified subgroups revealed that there were no significant interactions between treatment effect and any this website baseline clinical findings. Among patients with two or more prevalent vertebral fractures, the hazard ratio for incident vertebral

fractures was 0.61 (95% CI, 0.40–0.93) in favor of eldecalcitol over alfacalcidol. The hazard ratio for incident vertebral fractures among patients with a total hip BMD T-score of less than − 2.5 was 0.56 (95% CI, 0.34–0.90), indicating the superior effect of eldecalcitol among patients with low total hip BMD (Fig. 6). This 3-year trial demonstrated that eldecalcitol buy 17-AAG decreased the risk of vertebral fractures more than

did alfacalcidol. Subgroup analyses suggested that the effect of eldecalcitol on reducing risk of vertebral fractures is greater in patients with more severe osteoporosis, indicated by total hip BMD T-scores of less than − 2.5 or multiple fractures. The effect of alfacalcidol on vertebral fracture incidence has been examined. Some studies reported positive results [8] and [9], while others did not show a significant reduction in vertebral fractures with alfacalcidol [10] and [11]. A previous meta-analysis reported that active and native vitamin D3 reduced the risk of vertebral fracture [17]. However, that analysis did not have the power to distinguish the effect of alfacalcidol and 1,25(OH)2D3 from that of native vitamin D3, and the effect of active vitamin D3 was

influenced by one large study using 1,25(OH)2D3[18]. Thus, controversy remained as to the anti-fracture effect of active vitamin D3. In the present study, patients with serum 25(OH)D below 50 nmol/L were supplemented with 400 IU vitamin D3 daily, and serum 25(OH)D was over 50 nmol/L in more than 92% of the patients. Because the anti-fracture effect of eldecalcitol was observed among vitamin D-sufficient osteoporotic patients, the effects of eldecalcitol on fractures, as well as on BMD [6], were unlikely to be the effect of supplementing for vitamin D insufficiency. Eldecalcitol reduced vertebral fracture incidence Dimethyl sulfoxide with a suppression of urinary NTX as a bone resorption marker. As to the mechanism of the suppression of bone resorption, eldecalcitol was shown to reduce the number of preosteoblastic cells which interact with osteoclast precursors, resulting in a reduction in the number and activity of osteoclasts on the bone surface [19]. In agreement with these observations, in vivo administration of eldecalcitol to mice reduced perimeter of receptor activator of NF-kB ligand-positive cell surface around the trabecular bone (Saito H, et al. personal communication).