Meta-analysis of the relationship between homocysteine, vitamin B12, folate, and multiple sclerosis

A meta-analysis was conducted to assess the relationship between serum homocysteine, vitamin B-12, and folate levels in patients with multiple sclerosis (MS). The DerSimonian and Laird Q test was used to evaluate the degree of heterogeneity between studies and a funnel plot was used to assess publication bias. The pooled effect size (standardized mean difference [SMD]) between patients with MS and control patients) from a random effects model was 0.84 (95% confidence interval: 0.18, 1.49) for homocysteine and -0.25 (-0.45, -0.04) for vitamin B-12, and from a fixed effects model was 0.98 (0.80, 1.16) for homocysteine and -0.25 (-0.41, -0.09) for vitamin B-12. Both nutrients were statistically significant, but the SMD for folate was not. Patients with MS were found to have raised homocysteine levels but low B-12 levels, which might contribute to the pathogenesis of MS. (C) 2011 Elsevier Ltd. All rights reserved.