In Reply We based our clinical trial on a thorough understanding of the published data on the subject, which is conflicting.1- 4 First, the purpose of our study was to evaluate the effects of vitamin D and exercise separately and combined, among community-dwelling older women with a recent history of falls. Both interventions are commonly recommended for this population without baseline testing of the vitamin D levels. We agree with Prince et al that the effect of vitamin D supplementation could be different among persons who are vitamin D deficient. On the other hand, as Prince and colleagues point out, only 17% of our Finnish fall-prone study sample was vitamin D deficient, so it is hardly justified to recommend universal vitamin D supplementation for fall prevention.
Uusi-Rasi K, Patil R, Tokola K. Study Design for Vitamin D Randomized Clinical Trials—Reply. JAMA Intern Med. 2015;175(10):1720-1721. doi:10.1001/jamainternmed.2015.3768