Serum 25-hydroxyvitamin D level and risk of falls in Japanese community-dwelling elderly women: a 1-year follow-up study

A Summary The present prospective follow-up study among 1,393 community-dwelling elderly women aged 75 years or older was conducted to clarify the association between serum 25-hydroxyvitamin D (25(OH)D) level and risk of falls. Lower serum 25(OH)D, particularly level < 20 ng/mL, was significantly associated with an increased risk of falls. Introduction Serum 25(OH)D level has been revealed to be important factor not only for skeletal health but also for fall prevention among the elderly. Our previous cross-sectional study indicated that low serum 25(OH)D level is associated with inferior physical performance and falls among elderly Japanese women. The present prospective study was designed to clarify the association between serum 25(OH)D level and risk of falls before and after 1 year of follow-up. Methods The community-dwelling elderly women aged 75 years or older (N = 1,393) who participated in a mass health examination were followed 1 year later by a mailed self-administered questionnaire. Results Responses were obtained from 1,285 subjects (response rate = 92.2 %). The incidence of falls at baseline and at 1-year follow-up was 18.8 and 24.4 %, respectively. The baseline prevalence of serum 25(OH)D < 20 ng/mL was 35.2 %. Odds ratios (95 % confidence intervals) in the lowest tertile of serum 25(OH)D (< 20 ng/mL) compared with those in the highest tertile (a parts per thousand yen25 ng/mL) were 1.40 (1.01-1.94) for any falls and 1.47 (0.93-2.32) for recurrent falls vs. no falls adjusted for potential risk factors. Conclusions Among elderly Japanese women, the lower serum 25(OH)D, particularly level < 20 ng/mL, was significantly associated with an increased risk of falls.