serum 25(oh) vitamin d levels is not associated with disability in multiple sclerosis patients: a case-control study.

background: it seems that serum vitamin d levels are one of the potential environmental factors affecting the severity of multiple sclerosis (ms). in this study, we aim to evaluate vitamin d levels in ms patients and healthy subjects and assess the relationship between vitamin d level and disability. methods: in this case-control study, 168 rapid relapsing ms patients and 168 matched healthy controls were randomly included in this study. demographic characteristics and serum vitamin d levels for patients and controls, as well as expanded disability status scale (edss), duration of disease and diagnostic lag for patients were evaluated. we followed up patients for 6 months and relapses were recorded. results:   the  mean  serum  vitamin  d  levels  were 19.16 ± 17.37 inpatients and 25.39 ± 19.67 in controls (p = 0.560). the mean serum vitamin d levels were 12.65 ±  13.3 in patients with relapses and 22.08 ± 18.22 in  patients without any relapses (p < 0.001). there  was  no  significant  correlation  between  e ss score and serum vitamin d levels (r = −0.08, p = 0.280). there  was  a  significant  positive  correlation  between edss score and disease duration (r = 0.52, p < 0.001). conclusion: in conclusion, vitamin d level in patients with  ms  was  significantly  lower  than  the  healthy subjects,  but  no  significant  relationship  was  found between vitamin d levels and disability.  our findings did not suggest a protective role for serum vitamin d levels against disability.