Role of Vitamin D Supplementation in Improving Disease Activity in Rheumatoid Arthritis: An Exploratory Study

Aim: The aim of this exploratory study is to estimate the relationship between vitamin D (vit D) deficiency and active rheumatoid arthritis (RA), and the role of supplementation in improving disease activity.

Method: A randomized recruitment, consent screening, open-label interventional study was conducted in patients who fulfilled American College of Rheumatology/European League Against Rheumatism 2010 criteria for diagnosing RA and on stable disease-modifying anti-rheumatic drugs (DMARDs) for 3 months. Serum vit D levels and Disease Activity Score of 28 joints/C-reactive protein (DAS28-CRP) disease activity status were estimated at the first visit. Subjects with low vit D levels and DAS28-CRP > 2.6 were supplemented with vit D for 12 weeks, and were assessed for improvement in disease activity and serum vit D levels.

Results: One hundred and fifty RA patients of mean age 49 ± 12.1 years, mean duration of illness 78 ± 63 months, and on treatment with DMARDs for 44 ± 39 months were recruited for the study. Of these, 73 (49%) subjects were found to have DAS28-CRP > 2.6 and serum vit D below 20 ng/mL. The patients received vit D supplement of 60 000 IU/week for 6 weeks, followed by 60 000 IU/month for a total duration of 3 months. Disease activity and vit D status were assessed for 59 (80.8%) patients who reported at the end of 12 weeks of treatment. Mean DAS28-CRP of these patients showed a statistically significant improvement from 3.68 ± 0.93 at baseline to 3.08 ± 1.11 after supplementation (P = 0.002). Serum vit D levels improved from 10.05 ± 5.18 to 57.21 ± 24.77 ng/mL (P < 0.001) during the period.

Conclusion: Supplementation of vit D in RA patients with persisting disease activity and vit D deficiency contributed to significant improvement in disease activity within a short duration.