The anti-inflammatory role of the active metabolite of vitamin D, namely 1, 25-dihydroxyvitamin D3 (calcitriol), has been reported in multiple sclerosis (MS). Moreover, recent studies have shown that fibroblast growth factor 23 (FGF23) is involved in the regulation of calcitriol biosynthesis. The probable changes of FGF23 and calcitriol concentrations in the CSF and serum of patients with MS were evaluated. Calcitriol concentration in the CSF and serum of MS patients was significantly higher than that in non-MS patients, while FGF23 concentration in MS patients was comparable to controls. We concluded that calcitriol concentration increases in the CSF and serum of MS patients independent of FGF23 status.