VDR and postmenopausal osteoporosis: Out of 507 papers retrieved from Medline, Embase, Wanfang, VIP and CNKI, a total of 67 studies were taken into account, including case-controlled or cohort designed studies and those projects that provided genotypic prevalence rates of VDR polymorphisms in cases with postmenopausal osteoporosis and population-based controls.