The effects of vitamin D supplementation on disease activity and fatigue in Libyan rheumatoid arthritis patients.

Abstract

This study aimed to investigate the effect of vitamin D supplementation therapy on disease activity and fatigue in rheumatoid arthritis (RA) patients. A prospective randomized clinical trial was conducted at rheumatology clinics in Tripoli Central Hospital, Libya. The eligible patients received disease-modifying antirheumatic drugs (DMARDs) and were divided into two groups: group A received 50,000 IU of vitamin D once a week; while group B received conventional DMARDs without vitamin D supplementation. The groups were monitored for 12 weeks. The study included 68 RA patients, with the majority being female (75%). There were no significant differences in parameters such as age, sex, duration of illness, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), calcium, and vitamin D levels, as well as DAS28 (Disease Activity Score with 28-joint count) and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) levels between these two groups at baseline. After 12 weeks, group A showed a significant improvement in mean vitamin D levels and FACIT-F scores compared to group B. The increase in vitamin D levels in group A (24.21 ±4.81 nmol/l) was higher than that in group B (5.76 ±3.36 nmol/l). Furthermore, the FACIT-F score in group A was in the normal range (mean: 39.36 ±6.15), whereas group B still exhibited "abnormal" FACIT-F < 27.75 ±4.41. Correlation analysis indicated a positive correlation between FACIT-F and vitamin D levels, suggesting that higher vitamin D levels were associated with improved fatigue. Additionally, a weak inverse correlation was observed between DAS28 and vitamin D levels though the difference was not statistically significant (p > 0.05). Finally, the correlation between DAS28 and FACIT-F was positive (R = 0.557, p = 0.000). The results of the recent study indicated that vitamin D3 (50,000 IU of cholecalciferol) supplementation had a positive impact in RA patients compared to conventional DMARDs drugs, as was clear from the significant FACIT-F.