Higher levels of 25-hydroxyvitamin D are associated with a lower incidence of multiple sclerosis only in women.

INTRODUCTION: Multiple sclerosis (MS) is a chronic inflammatory disease with an as yet not fully understood etiological background. The geographical distribution of MS is striking with a prevalence that increases with latitude. For this reason, vitamin D deficiency is considered a possible pathogenic co-factor in MS. MATERIALS AND METHODS: To study the role of the vitamin D metabolism in MS, blood samples were taken twice (summer and winter) from 103 patients with MS and 110 healthy controls. Serum concentrations of 25-hydroxyvitamin D (25(OH) D) and 1,25-dihydroxyvitamin D (1,25(OH)(2)D) were measured, and detailed information on disease characteristics and environmental factors that might influence the vitamin D metabolite levels was collected. RESULTS: Mean serum 25(OH)D and 1,25(OH)(2)D concentrations were significantly higher in summer compared to winter in both patients and controls. Using logistic regression methods, we found that in women for every 10 nmol/L increase of serum 25(OH)D level the odds of MS was reduced by 19% (odds ratio 0.81; 95% confidence interval: 0.69-0.95), suggesting a "protective" effect of higher 25(OH)D serum levels. In addition, also restricted to women, a negative correlation was found between Expanded Disability Status Scale and 25(OH)D levels (r = -0.29, P = 0.020). CONCLUSIONS: Our data suggest that higher circulating levels of 25(OH)D are associated with a lower incidence of MS and MS-related disability in women. This may imply clues to the pathogenesis of the sex difference in risk and to the nature of the environmental factors involved in MS.

No evidence that polymorphisms of the vanishing white matter disease genes are risk factors in multiple sclerosis.

Febrile infections are known to cause exacerbations in the white matter disorders 'vanishing white matter' (VWM) and multiple sclerosis (MS). We hypothesized that polymorphisms in EIF2B1-5, the genes involved in VWM, might be risk factors for the development of MS or temperature sensitivity in patients with MS. We found no difference in the frequencies of 15 EIF2B1-5 variants between patients with MS and healthy controls, and none of the variants showed significant deviation of the Hardy-Weinberg equilibrium. Furthermore, sequencing data of EIF2B1-5 in 20 patients with MS and measurement of the activity of eIF2B complex in patient-derived lymphoblasts did not support our hypothesis.