Vitamin D receptor gene polymorphisms and the risk of Parkinson's disease

The effect of vitamin D receptor (VDR) gene polymorphisms on Parkinson's disease (PD) has recently gained interest. However, evidence on this relationship is controversial. We searched PubMed, EMBASE and the Cochrane Library database targeted all studies that evaluated VDR gene polymorphisms and PD up to April 2,014. A meta-analysis was conducted on the association between VDR ApaI, BsmI, TaqI and FokI polymorphisms and PD using (1) allelic contrast, (2) dominant, (3) recessive, and (4) additive models. A total of five relevant studies involving PD patients (n = 1,266) and controls (n = 1,649) were included in the analysis. There was a significant association between FokI polymorphism and PD. In the pooled allelic analysis, the F allele was associated with increased risk of PD (OR 1.41, 95% CI 1.14-1.75). In the genotype analysis, FF + Ff versus ff showed a significant association with PD in the dominant model (OR 2.32, 95% CI 1.49-3.61, P = 0.0002). FF versus ff showed a significant association with PD in the additive model (OR 2.45, 95% CI 1.52-3.93, P = 0.0002). There was also a statistically significant association between VDR BsmI polymorphisms in the recessive model, BB versus Bb + bb showed a significant increased risk of PD (OR 1.37, 95% CI 1.01-1.87, P = 0.04). No significant associations were observed between VDR ApaI and TaqI polymorphisms and PD. To sum up, VDR BsmI and FokI polymorphisms were associated with increased risk of PD.