Does Race Influence the Link Between Vitamin D Levels and MS Risk?

Higher levels of vitamin D may reduce risk for multiple sclerosis (MS) among White individuals, with this association being less significant among Black individuals, according to study results presented at the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) Congress 2025, held in Barcelona, Spain from September 24 to 26, 2025.

While low vitamin D has been linked to increased risk for MS in White individuals, there is limited research on this association in Black individuals.

Researchers studied the association between 25-hydroxyvitamin D and MS risk among White and Black military personnel in the US. Information was collected from the Department of Defense Serum Repository, which includes data from more than 10 million US military personnel. Individuals who developed MS during duty between 1992 and 2019 were eligible for inclusion. Patients with MS were matched 1:2 with control individuals, adjusting for age, sex, race and ethnicity, blood collection dates, and military branch.

Among White individuals, serum vitamin D levels ranged from 53 to 112 nmol/L across the lowest and highest quintiles, with 725 patients and 1432 controls. As vitamin D levels increased, risk for MS significantly decreased (odds ratios [OR] for increasing quintiles, 0.68, 0.45, 0.44, and 0.35; P =9.51e-14).

For Black individuals, vitamin D levels ranged from 31 to 72 nmol/L between the lowest and highest quintiles, with 358 patients and 690 controls. Although MS risk also decreased with higher vitamin D levels, this association was not statistically significant (OR for 50 nmol/L increases in vitamin D, 0.75; 95% CI, 0.47-1.18; P =.19).

“This is the strongest evidence to date that high circulating vitamin D may reduce MS risk in [White individuals] and vitamin D supplementation could prevent MS. The relation is less strong in [Black individuals] and could point to other prevailing biological mechanisms.”

Disclosures: Multiple authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.