Effect of Vitamin D Supplements on Relapse Rate and Expanded Disability Status Scale (EDSS) in Multiple Sclerosis (MS): A Systematic Review and Meta-Analysis.

BACKGROUND

Multiple sclerosis (MS) is an inflammatory disease while there are controversies regarding the role of vitamin D supplements in controlling relapse and disability improvement during treatment.

OBJECTIVE

The goal of this systematic review and meta-analysis was to evaluate the effect of vitamin D supplements on MS-related relapse and the Expanded Disability Status Scale (EDSS).

METHODS

We searched databases to include randomized clinical trials (RCTs) which were published up to October 2018. We included RCTs, being single-blinded or double-blinded or open-label trials in which one of the main outcomes was EDSS and/or relapse after vitamin D supplementation. All statistical analyses were performed using RevMan 5.3. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for relapse between treatment arms. The mean difference was calculated for EDSS comparisons.

RESULTS

Nine articles were included for analysis. Of these nine studies, five compared vitamin D supplement groups with placebo (group 1 studies), and four compared high- and low-dose vitamin D groups. A total of 561 patients were analyzed. Being treated with vitamin D instead of placebo showed no effect on relapse rate (OR = 0.66, 95% CI = 0.28-1.54) as well as EDSS (mean difference = 0.06, 95%CI [-0.31, 0.42]). The results of studies comparing high- vs. low-dose vitamin D interventions showed no significant effect on relapse rate (OR = 1.08, 95%CI [0.29-4.08] as well as final EDSS (mean difference = 0.17, 95% CI = -0.73, 1.07).

CONCLUSIONS

Our findings show that vitamin D supplements (high or low dose) have no significant effect on relapse rate and disability during treatment in MS patients.