Vitamin D Levels and Visual System Measurements in Progressive Multiple Sclerosis: A Cross-sectional Study

Abstract

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 levels 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 the Pearson correlation and the generalized linear mixed model.

Results: The analysis included 258 patients (mean ± SD age of 55.6 ± 7.3 years, 52.7% female, and 52.3% PPMS). Mean vitamin D values were above sufficiency and were similar between PPMS and SPMS (P = .47 and P = .31). There was no association between 25(OH)D₃ levels and any visual markers, including peripapillary retinal nerve fiber layer thickness (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 statistically significant associations between vitamin D levels and visual system measurements were detected in the PPMS and SPMS subgroups.

Conclusions: Vitamin D levels were not associated with optical coherence tomography findings or low-contrast letter acuity in this group of patients with progressive MS.

Keywords: Low-contrast visual acuity; Multiple sclerosis (MS); Optical coherence tomography (OCT); Progressive multiple sclerosis.

Figure 1.

Correlations between 25-hydroxyvitamin D3 (25[OH]D3) levels and visual parameters RNFL, retinal nerve fiber layer; GCIPL, ganglion cell–inner plexiform layer; LCVA, low-contrast visual acuity; MV, macular volume.