Serum 25-Hydroxyvitamin D Levels and Rate of Hip Bone Loss in Older Men

Context: Vitamin D deficiency is common among older adults, but the association between 25-hydroxyvitamin D [25(OH) D] levels and rates of bone loss is uncertain. Objective: Our aim was to test the hypothesis that lower 25(OH) D levels are associated with higher rates of hip bone loss in older men. Design and Setting: We conducted a prospective cohort study in six U. S. centers. Participants: A total of 1279 community-dwelling men aged 65 yr or older with 25(OH) D levels (liquid chromatography-tandem mass spectroscopy) and hip bone mineral density (BMD) (dual-energy x-ray absorptiometry) at baseline and repeat hip BMD an average of 4.4 yr later participated in the study. Main Outcome Measure(s): We measured the annualized percentage rate of change in hip BMD. Results: After adjustment for multiple potential confounders, the average rate of decline in total hip BMD was -0.59%/yr among men with 25(OH) D levels below 15.0 ng/ml, -0.54%/yr among men with 25(OH) D levels 15.0-19.9 ng/ml, -0.35%/yr among men with 25(OH) D levels 20.0-29.9 ng/ml, and -0.37%/ yr among men with 25(OH) D levels of at least 30 ng/ml (P trend = 0.008 for multivariable model). Evidence was strong to support an association among men aged 75 yr and older (P trend <0.001), but not among younger men (P trend = 0.55). Findings were similar when 25(OH) D level was expressed in quintiles and when BMD at hip subregions was substituted for total hip BMD. Conclusions: In this cohort of community-dwelling older men, men with 25(OH) D levels below 20 ng/ml had greater subsequent rates of hip bone loss, but rates of loss were similar among men with higher levels. These results lend support to the view that low 25(OH) D levels are detrimental to BMD in older men. (J Clin Endocrinol Metab 94: 2773-2780, 2009)