25-Hydroxyvitamin D and Severity of Parkinson’s Disease

. A role for vitamin D deficiency in Parkinson's disease (PD) has recently been proposed. Given the growing body of evidence for the association of vitamin D with several neurodegenerative disorders and unavailability of any published study in the Middle East, the present study is aimed to determine the associations of circulating 25-hydroxyvitamin D (25OHD) levels with the severity of PD in an Iranian sample. Methods . In 109 patients, the severity of PD was evaluated by using Hoehn & Yahr (HR) stages and Unified Parkinson's Disease Rating Stage (UPDRS) Part III compared with 25OHD level in a double-blind and cross-sectional study. Results . Mean ± SD levels of 25OHD were 28.5 ± 1.4 and 27.1 ± 1.5, for males and females, respectively. Also, 38.4% of the patients showed deficiency levels of 25OHD (<20 ng/mL), and 72.8% had insufficient levels (<30 ng/mL). High prevalence of 25OHD insufficiency in subjects with early disease was not associated with HR stage and UPDRS scores even after multivariate adjustment for possible confounders including disease duration. Conclusions . These findings are consistent with the possibility that vitamin D status does not seem to deteriorate during the early disease stages of PD. Further studies are needed to reveal the natural role and significance of vitamin D insufficiency in PD.