Vitamin D receptor gene and risk of fracture in postmenopausal women: a meta-analysis

Objective Fracture is the major clinical outcome of osteoporosis. The vitamin D receptor (VDR) gene is thought to be a candidate gene for osteoporosis. Many genetic studies have suggested an association of VDR polymorphisms and fracture risk, but evidence remains conflicting. The aim of this study was to evaluate the genetic effect of the BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene on fracture risk in postmenopausal women. Methods Relevant studies were identified from the following electronic databases: PubMed, Embase, and Web of Science before September 2013. Statistical analysis was performed by using the software STATA 12.0. A total 1975 fracture cases and 4565 controls in 14 studies with a total of 16 eligible comparisons were identified for data analysis. Results No evidence of relationship between the VDR BsmI, TaqI, ApaI or FokI polymorphisms and fracture risk was observed with any genetic model in postmenopausal women (BsmI: b vs. B: odds ratio (OR) 1.07, 95% confidence interval (CI) 0.90-1.29; TaqI: T vs. t: OR 0.89, 95% CI 0.68-1.15; ApaI: A vs. a: OR 0.91, 95% CI 0.76-1.08; FokI: F vs. f: OR 1.20, 95% CI 0.76-1.90). Conclusion This meta-analysis suggests that ApaI, BsmI, TaqI and FokI polymorphisms may be not associated with the risk of fracture in postmenopausal women. Further studies in a larger sample population are required to confirm this finding.