Goshayeshi L et al. – This study suggested that 25(OH)D plays a protective role against metabolic syndrome (MetS) in Rheumatoid arthritis (RA) patients. However, this cross–sectional study did not permit a power calculation on the causal relationship between Vitamin D (Vit D) and metabolic syndrome. On the other hand, Vit D has a negative correlation with body mass index (BMI) in these patients.

• This cross–sectional study was designed to evaluate the impact of serum Vit D on MetS and body mass index (BMI).
• One hundred twenty RA patients were enrolled.
• MetS was assessed according to Adult Treatment Panel III criteria.
• All patients with known confounders influencing Vit D serum levels were excluded.
• Serum value of 25–hydroxyvitamin D (25(OH)D) was measured using a commercial ELISA kit.
• Data were analyzed by SPSS software.

• A logistic regression analysis stated that prednisolone dosage [p = 0.028, β = 0.177, odds ratio (OR) = 1.194, confidence interval (CI, 1.09–1.32)], age [p = 0.002, β = 0.146, OR = 1.57, CI (1.05–1.27)] and Vit D serum levels [p = 0.049, β = –3.766, OR = 0.023, CI (0.001–0.978)] are all significant predictors of MetS occurrence in RA patients.
• It was shown that 25(OH)D is a protective factor against MetS.
• It was also shown that there is a negative correlation between BMI and 25(OH)D serum levels (P = 0.037, r s = –0.266).