Serum 25-hydroxyvitamin D and the risk of knee and hip osteoarthritis leading to hospitalization: a cohort study of 5274 Finns

Objective. The aim of this study was to investigate whether low levels of serum 25-hydroxyvitamin D [25(OH)D] predicts the development of knee or hip OA. Methods. The cohort consisted of 5274 participants in a national health examination survey who had no knee or hip OA at baseline. Information about the incidence of OA was drawn from the National Health Care Register. During the follow-up of 10 years (50 134 person-years), 127 subjects developed incident, physician-diagnosed OA in the knee and 45 in the hip joint. The information on covariates, including age, sex, education, BMI, work load, leisure time physical activity, smoking history, knee or hip complaint during the past month and previous injuries, was gathered at baseline. Serum 25(OH)D concentrations were determined from baseline serum samples. Results. After adjustment for age and gender, serum 25(OH)D showed statistically significant associations with known risk factors for OA except injuries. In the fully adjusted model, low serum 25(OH)D concentration did not predict increased incidence of knee and hip OA. Conclusion. The results do not support the hypothesis that low levels of serum 25(OH)D contribute to the development of knee or hip OA.