Eldecalcitol improves muscle strength and dynamic balance in postmenopausal women with osteoporosis: an open-label randomized controlled study

The antifracture efficacy of vitamin D in osteoporosis is due to its direct action on bones and indirect extraskeletal effects to prevent falls. Eldecalcitol is an analog of active vitamin D₃ that improves bone mineral density and reduces the risk of osteoporotic fractures. However, the effects of eldecalcitol on muscle strength and static and dynamic postural balance are unclear. In this open-label randomized controlled study, we assessed the effects of eldecalcitol on muscle strength and static and dynamic postural balance in 50 postmenopausal women (mean age 74 years) with osteoporosis treated with bisphosphonate. Participants were randomly divided into a bisphosphonate group (alendronate at 35 mg/week; n = 25) or an eldecalcitol group (eldecalcitol at 0.75 μg/day and alendronate at 35 mg/week; n = 25) and were followed up for 6 months. Trunk muscle strength, including back extensor strength and iliopsoas muscle strength, was measured. Static standing balance was evaluated and the one leg standing test was performed to assess static postural balance. Dynamic sitting balance was evaluated and the 10-m walk test, functional reach test, and timed up and go test were performed to assess dynamic postural balance. At 6 months, there were no significant changes in any measure of muscle strength or balance in the bisphosphonate group, whereas eldecalcitol significantly increased back extensor strength (p = 0.012) and iliopsoas muscle strength (p = 0.035). Eldecalcitol also significantly improved findings on the timed up and go test (p = 0.001) and dynamic sitting balance (p = 0.015) at 6 months. These results with eldecalcitol may have an impact on prevention of falls.