Source
Division of Hospital Medicine, Department of Medicine, University of California, San Diego, La Jolla, San Diego, CA 92093-0659, USA. tldam@ucsd.edu
Abstract
In women, but not men, lower 25-hydroxyvitamin D [25(OH)D] levels were associated with impaired performance on two lower extremity function tests in both cross-sectional and prospective analyses.
INTRODUCTION:
Preserved physical function may explain how 25(OH)D supplementation reduces falls and fractures.
METHODS:
A total of 1,065 community-dwelling men and women (mean age 74.6 years) with 25(OH)D levels and performance on timed up and go (TUG) and timed chair stand (TCS) were seen in 1997-1999; 769 (72%) participants returned for follow-up. Associations were examined using generalized linear models.
RESULTS:
25(OH)D levels were higher in men than women, but the prevalence of vitamin D insufficiency defined as 25(OH)D <75 nmol/L was 14%. There were no baseline sex differences in TUG or TCS. However, after 2.5 years, decline in TCS and TUG was greater in women than men (11% vs. 3%; p < 0.001). Women in the lowest 25(OH)D quartile (<80 nmol/L) compared to the highest quartile had an accelerated rate of functional decline on the TUG and TCS independent of covariates. No significant associations were seen in men.
CONCLUSION:
In women, but not men, lower 25(OH)D levels were associated with impaired performance on two lower extremity function tests in both cross-sectional and prospective analyses. These results provide additional evidence that 25(OH)D is associated with physical function, which may explain how vitamin D supplementation reduces falls and fractures.