Lower 25-Hydroxyvitamin D is Associated with Higher Relapse Risk in Patients with Relapsing-Remitting Multiple Sclerosis

To investigate the association between serum circulating 25-hydroxyvitamin D [25(OH) D] concentrations and exacerbation risk in Chinese patients with relapsing-remitting multiple sclerosis (RR-MS). From January 2014 to December 2014, consecutive RR-MS patients admitted to the Department of Neurology of our hospital were identified. Blood samples for 25(OH) D measurements were taken at admission. All included patients visited the outpatient clinic of our hospital 1 year after admission. The influence of serum 25[OH] D levels on exacerbation was performed by binary logistic regression analysis. In this study, 109 patients finished the follow-up. Median follow-up time was 1 year (range 1.0-1.1). Twenty-one out of the 109 was at risk period for infection. A total of 32 patients experienced a total of 76 exacerbations during the study. In the follow-up, a total of 32 patients experienced exacerbations. Thus, the exacerbation rate was 29.4% (95%CI: 20.8%-37.9%). Exacerbation rates were found to decrease with increasing levels of serum 25-OH-D concentrations. For the quartiles category, the risk of an exacerbation was significantly increased in the group with first quartile compared to the group with fourth. Rate ratios for the first, second and third group were 4.2, 3.3 and 2.0, respectively (p for trend =0.011) when compared with the fourth group. Simultaneous evaluation of quartile categories of levels of serum 25(OH) D and infections showed that both factors were related to the exacerbation rate. The data demonstrates that lower vitamin D status is a sign of more active disease in patients with RR-MS and suggests a beneficial effect of vitamin D on disease course in MS.