Vitamin D receptor BsmI polymorphism and osteoporosis risk: a meta-analysis from 26 studies.

OBJECTIVE Growing evidence has shown that vitamin D deficiency can cause lower bone mineral density (BMD) and an increased risk of osteoporosis. Vitamin D receptor (VDR) BsmI polymorphism (rs1544410) can affect BMD variation and circulating osteocalcin levels. To date, a wide range of epidemiological studies have been carried out to evaluate the association between VDR BsmI polymorphism and susceptibility to osteoporosis. Conflicting results, however, were obtained. The aim of this study was to evaluate the effect of VDR BsmI polymorphism on osteoporosis risk using a meta-analysis. METHODS Twenty-six publications were identified by searching PubMed and Embase databases. The association between VDR BsmI polymorphism and osteoporosis was estimated by calculating pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). RESULTS The bb genotype was associated with a significantly decreased risk of osteoporosis in overall comparison (bb vs. BB: OR=0.61, 95% CI, 0.40-0.92; bb vs. BB/Bb: OR=0.70, 95% CI, 0.52-0.95, respectively). Subgroup analyses showed that the bb genotype had a decreased risk of developing osteoporosis in postmenopausal women (bb vs. BB/Bb: OR=0.68, 95% CI, 0.46-0.98) and Africans (Bb/bb vs. BB: OR=0.18, 95% CI, 0.09-0.37). CONCLUSION The VDR BsmI polymorphism may have a protective role against the development of osteoporosis.