Vitamin D deficiency and multiple sclerosis relapse: a meta-analysis.

Area of Science:

• Neurology
• Endocrinology
• Nutritional Science

Background:

• Multiple sclerosis (MS) is a chronic autoimmune disease affecting the central nervous system.
• Vitamin D deficiency is common in MS patients and may influence disease activity.
• The relationship between vitamin D levels and MS relapse rates requires further clarification.

Purpose of the Study:

• To systematically evaluate the dose-response relationship between serum 25-hydroxyvitamin D [25(OH)D] and annualized relapse rate (ARR) in MS.
• To investigate the efficacy of vitamin D supplementation in reducing MS relapse risk.

Main Methods:

• A meta-analysis of randomized controlled trials (RCTs) published up to April 2025.
• Searches conducted across major databases including PubMed, Medline, Web of Science, Cochrane Library, and EMBASE.
• Study quality assessed using the Cochrane RoB-2 tool; meta-analyses performed using RevMan 5.3.

Main Results:

• Nine studies with 1,078 participants were included.
• Vitamin D supplementation significantly increased serum 25(OH)D levels (pooled MD = 44.97).
• Low/medium-dose vitamin D significantly reduced ARR (pooled MD = -0.14), but high-dose did not (pooled MD = 0.05). No overall significant ARR reduction was found.

Conclusions:

• Vitamin D supplementation effectively increases serum 25(OH)D levels in MS patients.
• Low/medium-dose vitamin D may be beneficial in reducing MS relapses, whereas high-dose supplementation shows no significant effect.
• Vitamin D supplementation did not significantly impact Expanded Disability Status Scale (EDSS) scores.