25 Hydroxyvitamin D concentrations in patients with optic neuritis as a clinically isolated syndrome and healthy controls

ABSTRACT

The onset of multiple sclerosis in the majority of the cases occurs as a clinically isolated syndrome [CIS]. We sought to assess serum levels of 25-hydroxyvitamin D [25-OHD] in CIS patients and healthy controls. In this cross-sectional study 40 patients [36 women and 4 men] with CIS manifesting as a single isolated optic neuritis and 40 Age- and sex-matched healthy controls [35 women and 5 men] were enrolled between late October 2010 and early March 2011. General vitamin D deficiency was defined as serum 25-OHD levels of lower than 20 ng/ml and was classified as mild [15 < 25-OHD <20 ng/ml], moderate [8 < 25-OHD <15 ng/ml], and severe [25- OHD <8 ng/ml]. We found no difference in the median interquartile range [IQR] between CIS patients and controls [17.95 [10.40- 29.13] vs. 17.00 [12.25-31.00]; P=0.57]. However, when stratified by the levels of deficiency, among CIS patients a significantly higher proportion had severe vitamin D deficiency in comparison to healthy controls [20% vs. 2.5%; P=0.034]. Nevertheless, the frequency of general [62.5% vs. 60%, P=0.82], mild [25% vs. 30%, P=0.80], and moderate [17.5% vs. 27.5%, P=0.42] vitamin D deficiency were not different between the two groups. Our findings do not indicate any significant difference of serum 25-OHD between CIS patients and healthy controls. However, in our series severe vitamin D deficiency was more frequent among CIS patients.