Evaluation of the Clinical Outcomes Associated With the Use of Fatty Acids and Vitamin D in Rheumatoid Arthritis Patients: A Systematic Review and Meta-Analysis.

Non-pharmacological therapies such as dietary interventions, fatty acids and vitamin supplementation, and physical changes are emerging as complementary treatments in the management of rheumatoid arthritis. Fatty acids (omega-3 fatty acids) and vitamin D modulate inflammatory pathways and decrease the production of inflammatory mediators having a beneficial effect on RA symptoms. The meta-analysis synthesized data from randomized controlled trials (RCTs) and investigated the effects of fatty acids and vitamin D supplementation in RA patients using clinical outcomes. A systematic literature review was conducted using MEDLINE and Central databases for RCTs that involved the administration of fatty acids (n = 14 trials) or vitamin D (n = 10 trials) versus conventional treatment adult RA patients. Clinical outcomes such as Disease Activity Score in 28 joints (DAS28), tender and swollen joint counts (TJC and SJC), patients global assessment (PGA), health assessment questionnaire (HAQ) and the visual analogue scale (VAS) for pain assessment were determined at baseline and the end of the study. Meta-analysis was performed using RevMan to assess the risk of bias and determine the mean differences and significance between the intervention and control groups. Data were analyzed from 24 RCTs with 1713 patients. Fatty acid administration caused a significant improvement in DAS28 (p < 0.0001), TJC (p < 0.0001) and HAQ scores (p < 0.00001) but there was no significant difference in SJC, PGA, and VAS scores relative to controls. In contrast, vitamin D supplementation only significantly improved HAQ (p = 0.02). However, fatty acid and vitamins showed a favorable effect on most clinical outcomes, which may be clinically relevant. This work suggests a moderate improvement in certain domains of clinical outcomes of RA patients with fatty acids and vitamin D. Since the trials used in the analysis were heterogenous and had a limited sample size, larger, multi-centre trials are needed to validate the efficacy of these interventions.