[Vitamin D and multiple sclerosis. A prospective survey of patients of Poitou-Charentes area].

Introduction: Recent reports demonstrate the implication of vitamin D in multiple sclerosis (MS).

Methods: In a multicentric regional study (Poitou-Charentes area) during the first trimester 2010, we measured the 25-OH vitamin D serum level in 170 consecutive MS patients, and in 170 controls matched for age (±4 years), sex and date of blood sample analysis. We searched for correlations between 25-OH vitamin D serum levels and the MS form, the disability (EDSS), the relapse rate during the previous year and the presence and number of enhancing lesions on T1-weighted MRI dating less than 12 months in relapsing MS.

Results: Hypovitaminosis D was very frequent in MS patients and 25-OH vitamin D serum level was significantly lower (14.5 ± 9.2 mcg/mL) in MS patients than in the control group (16.7 ± 9.6 mcg/mL). This serum level was inversely correlated with the degree of disability measured with EDSS score and was lower in secondary progressive (RR-SP) and primary progressive (PP) MS than in relapsing MS (RR). No correlation was found between 25-OH vit D serum level and relapse rate during the previous year in RR MS and the presence and number of enhancing lesions on T1-weighted MRI dating from less than 12 months.

Conclusion: 25-OH vit D serum level is very low in MS, mainly in RR-SP and PP MS and is correlated with disability. This suggests MS patients should be screened for vitamin D deficiency and given supplementation systematically when hypovitaminosis D is discovered.