ORIGINAL ARTICLE Vitamin D status and falls, frailty, and fractures among postmenopausal Japanese women living in Hawaii P. Pramyothin & S. Techasurungkul & J. Lin & H. Wang & A. Shah & P. D. Ross & R. Puapong & R. D. Wasnich Received: 7 October 2008 / Accepted: 9 February 2009 / Published online: 24 March 2009 # International Osteoporosis Foundation and National Osteoporosis Foundation 2009 Abstract Summary 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. Introduction 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. Methods Of 510 community-dwelling women who partic- ipated 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 measure- ments, 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. Results 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. Conclusions 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. Keywords Fall . Fracture . Frailty . Hawaii . Postmenopausal . Vitamin D Introduction Although there is no consensus on optimal serum levels of 25-hydroxyvitamin D (25-OHD), vitamin D deficiency is defined by many as 25-OHD <10 ng/mL (25 nmol/L) or <12 ng/mL (30 nmol/L). Some consider a 25-OHD level of Osteoporos Int (2009) 20:1955–1962 DOI 10.1007/s00198-009-0910-5 The authors (P. Pramyothin, S. Techasurungkul, J. Lin, H. Wang, A. Shah, P.D. Ross, R. Puapong, and R.D. Wasnich) are responsible for the work described in this paper. PP and RDW are the primary authors of the manuscript. PDR provided input on revising the manuscript and analyses based upon his prior knowledge of this study database. JL, HW, and AS performed data analyses and participated in interpreting the results and commenting on the manuscript. All authors provided substantial input in critically reviewing the manuscript and approved the final version. P. Pramyothin University of Hawaii Internal Medicine Residency Program, Honolulu, HI, USA S. Techasurungkul Tokyo Medical and Dental University, Tokyo, Japan P. Pramyothin : S. Techasurungkul : R. Puapong : R. D. Wasnich (*) Hawaii Osteoporosis Center, 401 Kamakee Street, Suite 314, Honolulu, HI 96814, USA e-mail: rwasnich@gmail.com J. Lin : H. Wang : A. Shah : P. D. Ross Merck Research Laboratories, Rahway, NJ, USA