Vitamin D status and falls, frailty, and fractures among postmenopausal Japanese women living in Hawaii

Abstract

Vitamin D status and its relationship to physical performance, falls, and fractures in 495 postmenopausal women of Japanese ancestry in Hawaii were investigated. The mean 25-hydroxyvitamin D (25-OHD) was 31.94 ng/mL. No significant association of 25-OHD was demonstrated with most outcomes, possibly due to higher 25-OHD levels in this population. In this study, we investigated vitamin D status and its relationship to physical performance, muscle strength, falls, and fractures in postmenopausal Japanese females living in Hawaii. Of 510 community-dwelling women who participated in the eighth examination of the Hawaii Osteoporosis Study, 495 were included in these analyses. Multivariate regression models were used to evaluate the relationship of 25-OHD (D(3) and total) to eight performance-based measurements, 12 activities of daily living (ADLs), and muscle strength (grip, triceps, and quadriceps). Logistic regression analyses were performed to evaluate the relationship of 25-OHD to falls, vertebral fractures, and non-vertebral fractures. The mean total 25-OHD was 31.94 +/- 9.46 ng/mL; 44% of subjects had values <30 ng/mL, while none had values <10-12 ng/mL. There was little evidence of seasonal variation. Among performance-based measures, ADLs, and strength tests, only quadriceps strength was significantly associated with total 25-OHD (p = 0.0063) and 25-OHD(3) (p = 0.0001). No significant association of 25-OHD was found with vertebral or non-vertebral fractures, or incidence of one or more falls. Lack of serum 25-OHD relationship with falls and fractures or most physical performance measures in this study may be related to the low prevalence of very low 25-OHD levels in this population.