Is vitamin D effective on the disease activity index (DAS28) in rheumatoid arthritis?

Background: We can prevent developing osteoporosis in rheumatoid arthritis (RA) patients with compounds containing calcium and vitamin D. In some of the studies, patients who received more vitamin D had better disease control. Our aim in this study was to observe whether the vitamin D could be effective on the rheumatoid arthritis disease activity or not? Methods: This study was a double blind randomized controlled clinical trial on 117 patients with rheumatoid arthritis. In Intervention group, in addition to drug therapy, vitamin D 50000 units per week were prescribed. Control group also received placebo tablets. In the end of study, results in both groups compared. Data analysis was performed by paired t-test, Student t-test and General linear Model. Finding: There were no significant differences in baseline disease severity, and DAS-28 in both groups. DAS-28 in intervention and control groups was 5.4 ± 1.1 and 5.5 ± 1.3, respectively (P > 0.05). In both groups, all clinical and laboratory parameters after intervention were reduced. The amount of reductions in intervention group was more than the placebo group but it is not significant. Conclusion: According to this research vitamin D can use as an adjuvant therapy for rheumatoid arthritis.