Abstract
Background and aims The aim of this study was to assess vitamin D status in patients with multiple sclerosis (MS) and to evaluate whether it was associated with oxidative and nitrosative stress (O and NS) markers and disability.
Methods This study included 137 patients with MS and 218 healthy controls. The markers evaluated were serum levels of 25-hydroxyvitamin D, lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter TRAP/UA.
Results MS patients presented higher age (p<0.0001), and lower 25(OH)D (p=0.002), NOx, and TRAP/UA (<0.0001) than controls. When the age was used as an additional explanatory variable in binary logistic regression analyses, 25(OH)D, NOx, and TRAP/UA remained significant (p=0.016, p<0.0001, and p=0.002, respectively). Patients with 25(OH)D<20 ng/mL showed higher EDSS (p=0.016) and lower AOPP (p=0.046) than those with 25(OH)D≥20 ng/mL. After the binary logistic regression analyses, EDSS remained significantly associated with vitamin D deficiency. We showed that lower levels of 25(OH) were associated with higher EDSS independently of variables such as O and NS (AOPP and NOx), age, sex, body mass index, ethnicity, disease duration, MS therapy, use of interferon beta, and clinical forms of MS (odds ratio: 1.380, 95% confidence interval 1.030–1.843, p=0.031). Moreover, the study showed an association between serum levels of 25(OH)D and EDSS (r2=0.115, p=0.002), demonstrating that 25(OH)D may contributed with 11.5% of increase in EDSS.
Conclusions Our results suggest that vitamin D deficiency may be considered one of the predictors of the disability in MS patients, independently of their redox status.
