Retinol levels are associated with magnetic resonance imaging outcomes in multiple sclerosis

Background: Vitamin A has immunomodulatory properties and may regulate the transcription of genes involved in remyelination. Objective: To investigate the association between retinol and disease activity in multiple sclerosis (MS). Methods: Cohort study of 88 relapsing-remitting MS patients, originally included in a randomised placebo-controlled trial of omega-3 fatty acids in MS (the OFAMS study), followed prospectively for 24 months with repeated assessments of serum-retinol and magnetic resonance imaging (MRI). All patients were initiated on interferon beta-1a after month 6. Results: Each 1 mu mol/L increase in serum-retinol reduced the odds (95% confidence interval) for new T1 gadolinium enhanced (Gd+) lesions by 49 (8-70)%, new T2 lesions by 42 (2-66)%, and combined unique activity (CUA) by 46 (3-68)% in simultaneous MRI scans, and 63 (25-82)% for new T1Gd(+) lesions, 49 (3-73)% for new T2 lesions and 43 (12-71)% for CUA the subsequent month. Serum-retinol also predicted new T1Gd(+) and T2 lesions six months ahead. The associations were not affected by HLA-DRB1*15, or serum levels of 25-hydroxyvitamin D, eicosapentaenoic acid or docosahexaenoic acid. Conclusion: Serum retinol is inversely associated with simultaneous and subsequent MRI outcomes in RRMS.