To study the association between vitamin D levels and RA.
Seventy-two postmenopausal female patients with RA (group RA) and fifty-eight healthy volunteers (group control) were included in this study. 25-hydroxyvitamin D3 (25-(OH) D3) levels were determined by ELISA method and disease activity of RA was assessed according to the Disease Activity Score in 28 joints (DAS28). The difference of 25-(OH) D3 levels between two groups and the relationship between 25-(OH) D3 levels and DAS28 were assessed.
25-(OH) D3 levels in peripheral blood in group RA were significantly lower than that in group control (P < 0.05), and 25-(OH)D3 levels were negatively correlated with DAS28.
Vitamin D may have double actions of prevention, treatment and evaluation during the diagnosis and treatment process with RA disease.