Effect of Vitamin D on Multiple Sclerosis Relapse

Background: Multiple Sclerosis (MS) is an immune-mediated inflammatory disease that affects 400,000 people in the United States. Relapsing-remitting MS is the most common form of MS where the relapses leads to progressive disability. Prior research has shown equivocal results with regards to vitamin D lowering MS relapse rates.

Objectives: The aim of this study was to investigate the correlation between vitamin D and MS relapse. It was hypothesized that MS patients who were taking vitamin D would have a lower recurrence of relapse when compared to MS patients who were not taking vitamin D.

Methods: A retrospective chart review was conducted in patients presenting to the ambulatory neurology clinic with an ICD-9/ICD-10 diagnosis of MS between the period of January 2015 and March 2017. Data abstracted from the chart between January 2015 and March 2017 included whether or not the patient was on vitamin D, whether or not the patient had a relapse and the number of relapses the patient had. The group taking Vitamin D and the group not taking Vitamin D were compared for occurrence of MS relapse using a χ² test and Odds Ratio (OR) analysis. Their number of MS relapses were also compared using a Mann-Whitney test.

Results: We identified 100 MS patients (mean age ± SD = 36.34 ± 11.24 years; 72% females, 46% white, 47% black, 7% others; 1% Clinically Isolated Syndrome, 93% Relapse-Remitting MS, 4% Secondary-Progressive MS, 2% Primary-Progressive MS). Patients were on vitamin D2 (600 - 50,000 units daily) or vitamin D3 (1,000 – 50,000 units daily). The cross sectional analysis showed that 38 were on vitamin D (6 of whom had a relapse) and 62 were not on vitamin D (19 of whom had a relapse). The chi-square test showed an association between vitamin D and MS relapses that was not statistically significant χ² (1, N = 100) = 2.04, p =.15, odds ratio= 0.42, 95% CI [0.15 to 1.19]. The Mann-Whitney test indicated that the number of relapses were not significantly different for patients on vitamin D (median relapse(s) = 0, range = 0-4) than for patients not on vitamin D (median relapse(s) = 0, range = 0-7) U=1006.0, p = 0.11.

Conclusions: Our retrospective study shows a lower proportion of relapse in the vitamin D group compared to the non-vitamin D group, which did not reach statistical significance. This study helps us estimate the needed sample size for a future prospective study adjusting for potential confounders.