Vitamin D status in patients with multiple sclerosis: an association with insolation, disease course, and HLA-DRB1 gene polymorphism
Recent systematic reviews and a meta-analysis have shown that there is insufficient evidence on the relationship of multiple sclerosis (MS) to vitamin D supplementation Objective: to assess the relationship of vitamin D status in MS patients to insolation, disease course, and HLA-DRB1 gene polymorphism. Patients and methods. The one-stage study enrolled 90 patients with relapsing-remitting MS (a study group) and 87 volunteers without this disease (a control group). The enrolled were born and live in the Altai Territory of the Russian Federation. The serum level of 25(OH)D was measured by enzyme immunoassay. Results and discussion. 25(OH)D <30 ng/ml was more common in patients with MS than that in the controls. There were no intergroup differences in the time spent in the sun for 6 months before inclusion in the study (p=0.020). The level of 25(OH)D was higher in the high insolation period from April to September than that in the low insolation period from October to March in both patients with MS (p<0.005) and controls (p<0.001). There was no association of 25(OH)D levels with urban and rural residence, gender, age at MS onset, severity of neurological disorders, their progression rate, and MS risk alleles within the HLA-DRB1 gene (03, 13, 15). Conclusion. Vitamin D deficiency is more common in patients with MS than in those without this disease. This is unlikely to be due to the differences in the radiation received from the sun. The final conclusion on the relationship of vitamin D to MS can be made after obtaining the results of a prospective follow-up.