Vitamin D receptor gene BsmI and TaqI polymorphisms and fracture risk: a meta-analysis

INTRODUCTION: 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 osteoporosis, but evidence remains conflicting. MATERIALS AND METHODS: We searched published studies from 1996 to September 2005 through PubMed and evaluated the genetic effect of the BsmI and TaqI polymorphism of VDR on fracture risk in a meta-analysis. Thirteen studies with a total of 20 eligible comparisons (1632 fracture cases and 5203 controls) were analyzed with fixed and random effects models. RESULT: No evidence of relationship between the VDR BsmI or TaqI polymorphism and fracture risk was observed with any genetic model. The odds ratio (95% confidence interval) of b-allele versus B-allele was 0.98 (0.86-1.12) with random effects calculations. There was significant between-study heterogeneity. Small studies did not differ significantly from larger ones. CONCLUSION: No relationship of the VDR BsmI or TaqI polymorphism and fracture risk was found in the meta-analysis of published data.