Background: Vitamin D deficiency is associated with increased disease activity in multiple sclerosis (MS) but its role in progressive MS has not been elucidated. The objective was to determine the correlation between vitamin D and visual parameters in primary progressive MS (PPMS) and secondary progressive MS (SPMS).
Methods: Serum 25-hydroxyvitamin D (25[OH]D) and 25-hydroxyvitamin D3 (25[OH]D3) levels were obtained from the Secondary and Primary Progressive Ibudilast NeuroNEXT Trial in MS (SPRINT-MS). Visual function measurements and vitamin D associations were determined using Pearson correlation and generalized linear mixed model.
Results: 258 patients (age 55.6 ± 7.4, 52.7% female, and 52.3% PPMS) were included in the analysis. Levels were similar between PPMS and SPMS for 25[OH]D (Mean 46.4 vs. 48.2 ng/ml P = .31) and 25[OH]D3 (39.8 vs. 41.4 ng/ml P = .47) all of which were above sufficiency. There was no association between 25[OH]D3 levels and any visual markers including retinal nerve fiber layer (Spearman r = −0.08), macular volume (r = −0.03), ganglion cell-inner plexiform layer (r = −0.07) and 2.5% low contrast visual acuity test (r =−0.10). No significant association between vitamin D level and visual system measurements were detected in either PPMS and SPMS subgroups.
Conclusions: Vitamin D levels were not associated with OCT or low contrast letter acuity in this group of patients with progressive MS.