Vitamin D and MRI measures in progressive multiple sclerosis

Background: Vitamin D deficiency is a proposed risk factor for multiple sclerosis (MS), but its role in progressive MS is not well understood. Objective: To examine the association between vitamin D levels and MRI features in primary progressive (PPMS) and secondary progressive MS (SPMS). Methods: Serum 25-hydroxyvitamin D (25[OH]D) and 25-hydroxyvitamin D-3 (25[OH]D-3) levels were obtained from 267 subjects enrolled into the Secondary and Primary Progressive Ibudilast NeuroNEXT Trial in Multiple Sclerosis (SPRINT-MS). Associations between imaging data and vitamin D levels was determined using Pearson or Spearman correlation and multivariate regression analyses. Results: 267 patients (age 55.6 +/- 7.4, 47.2% male, and 51.3% PPMS) were evaluated with quantitative MRI and vitamin D levels. 25(OH)D and 25(OH)D-3 were similar between PPMS and SPMS. There was no significant association between vitamin D and T1/2 lesion volume and brain parenchymal fraction. Modest associations were found between 25(OH)D-3 and whole brain-magnetization transfer ratio (WB-MTR, r = 0.17, p = 0.007) and normal appearing grey matter MTR (NAGM-MTR, r = 0.15, p = 0.02). Conclusions: 25(OH)D-3 levels were not associated with brain volume or lesional measures in progressive MS contrary to what has been described in relapsing remitting MS. An association between WB-MTR and NAGM-MTR suggest higher vitamin D levels may exert a protective role on myelin content in progressive MS.