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.