Risk of Osteoarthritis is Positively Associated with Vitamin D Status, but Not Bone Mineral Density, in Older Adults in the United States

Objective We examined the risk of osteoarthritis (OA) according to vitamin D status and bone mineral density (BMD) using a cross-sectional nationally representative database. Methods National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2010 were used to assess the relationship between OA and vitamin D status in adults aged >= 40 years (n = 2934). NHANES data from 2005 to 2010 and 2013 to 2014 were analyzed to investigate the association between OA and BMD (n = 5949). Vitamin D status was categorized as serum 25-hydroxyvitamin D (25OHD) <20 ng/mL or >= 20 ng/mL. Bone health was classified according to T-score (normal, osteopenia, or osteoporosis) and BMD tertile. Risk of OA was assessed using logistic regression and adjusted for covariates. Results Participants with serum 25OHD <20 ng/mL had a 37% lower risk of OA (95% confidence interval (CI) [0.39-0.99], P = 0.046). When stratified by sex, the odds ratio for OA in men with lower vitamin D status was 0.35 (95% CI [0.15-0.81], P = 0.02). No association was found in women. The risk for OA did not differ according to BMD tertile or T-score classification. Conclusions The risk of OA is lower in older men with 25OHD less than 20 ng/mL but not in older women. Bone mineral density is not associated with OA risk in older adults in the United States.