VDR and rheumatoid arthritis: The VDR rs2228570 genotyping (FokI) could not predict RA disease from control (AUC 0.43, 95% CI 0.32–0.53; p = 0.15) or patients with and without osteoporosis (AUC 0.48, 95% CI 0.37–0.6; p = 0.8).