Relationship between vitamin D receptor gene polymorphisms and anemia in postmenopausal Vietnamese women

Background: Both in vitro and in vivo studies have shown that calcitriol, the active form of vitamin D, is involved in hematopoiesis. Vitamin D receptor (VDR) gene has been suggested as one of the candidate genes for anemia. Objective: Investigate relationship between anemia and the commonly studied polymorphisms of VDR gene (FokI, BsmI, ApaI and TaqI) in terms of genotype and haplotype in Vietnamese. Methods: A case-control study including 132 postmenopausal women without chronic kidney diseases was designed to investigate the relationship between VDR polymorphism and anemia. Four single nucleotide polymorphisms (SNPs) FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) were typed by polymerase chain reaction and restriction fragment length polymorphism method. Results: Genotype distributions of four SNPs were in Hardy-Weinberg equilibrium in both anemia and control groups. The SNPs at the 3’end of the VDR gene (BsmI, ApaI and TaqI) exhibited a strong linkage disequilibrium. There was no significant association between anemia and VDR polymorphism in terms of allele, genotype, and haplotype in the analyses unadjusted or adjusted for the covariates (age, body mass index, educational level, serum ferritin, iron and albumin). Conclusion: VDR gene did not influence anemia in postmenopausal women without chronic kidney disease. For further study on the association between VDR gene and anemia, the use of larger sample size, a prospective study design, and additional markers would enhance the reliability and validity of findings.