Okazaki R, et al. - In this post hoc analysis, the researchers examined factors associated with inadequate response (IR) to risedronate in Japanese patients with osteoporosis. Participants were one thousand, two hundred sixty-one Japanese osteoporosis patients who received risedronate for 1 year in phase III trials. According to the findings obtained, low serum 25(OH)D and bone turnover markers (BTM), as well as, high bone mineral density (BMD) at baseline were independent predictors of an IR to risedronate in Japan. The results obtained from the study emphasized the importance of the assessment of serum 25(OH)D and BTM in the management of osteoporosis with bisphosphonates.