Background: Vitamin D receptor (VDR) polymorphisms have been inconsistently investigated in rheumatoid arthritis (RA). However, published studies demonstrated differences concerning design and effect size. A meta-analysis is necessary to determine the magnitude of the association between VDR polymorphisms and RA risk. Objective: The aim of the current study was to quantify the magnitude of the association between TaqI, BsmI, and FokI VDR polymorphisms with RA risk. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search and meta-analysis of the literature were conducted. Analyses were performed in the random effects model by using recessive, dominant, codominant, homozygous, and allele contrast models. Results: A total of 1703 cases and 2635 controls in 12 case-control studies were included in the meta-analyses. Results indicated a significant association between TaqI polymorphism and RA disease in homozygous, codominant and allele contrast models (P= 0.008, P= 0.015, P= 0.006 and P= 0.002, respectively). Association between BsmI polymorphism and RA risk was marginal in the dominant, codominant and allele contrast models (P= 0.057, P= 0.071, and P= 0.069, respectively). Te association between FokI polymorphism and RA risk was significant in the recessive, dominant and allele contrast models (P= 0.045, P= 0.027, and P= 0.013, respectively). Subgroup analysis showed that publication year, ethnicity, age, latitude, and estimated 25(OH)D levels influenced significantly the association between VDR polymorphisms and RA risk. Conclusion: TaqI and FokI VDR polymorphisms contributed significantly to RA risk. Study characteristics influenced the association between VDR polymorphisms and RA disease.
