Association of vitamin D status with multiple sclerosis in a case-control study from Morocco

Background. - Growing evidence suggests that hypovitaminosis D contributes to the pathogenesis of multiple sclerosis (MS). Objective. - This study aimed to evaluate whether vitamin D levels are associated with having MS and some of its characteristics in the Moroccan population. Methods. -Using liquid chromatography-tandem mass spectrometry, the 25(OH) D-3 metabolite was measured to quantify vitamin D serum levels (DSLs) in 113 patients with MS and 146 healthy controls matched for gender and age. DSLs were then compared between patients and controls, with correlations sought between DSLs and gender, age at onset, disease duration, MS type, degree of disability (EDSS score) and disease severity (MSSS) in patients. Results. - Hypovitaminosis D (DSL < 30 ng/mL) was observed in 97.3% of MS patients and in 98.6% of controls. Although the mean DSL was slightly lower in patients (11.69 +/- 6.97 ng/mL) than in controls (12.98 +/- 6.58 ng/mL), there was no significant association between DSL and MS status (P = 0.131). Similarly, among patients, no apparent association was found between DSL and MS type (P = 0.214), EDSS score (P = 0.076) or MSSS (P = 0.772). Conclusion. - Our study suggests that DSL is not associated with having MS nor with MS type, degree of disability or disease severity in the Moroccan population. On the other hand, DSL was lower in women and decreased with age. (C) 2018 Elsevier Masson SAS. All rights reserved.