Evaluation of the association of polymorphisms of the vitamin D receptor gene (VDR) with idiopathic recurrent pregnancy loss among women in Kazakhstan

There is considerable global discourse on the impact of insufficient vitamin D levels, known for their immunosuppressive properties, on recurrent pregnancy loss. Vitamin D deficiency affects 35% to 80% of the population. Despite advancements in molecular genetics, the study of vitamin D receptor gene (VDR) polymorphisms remains crucial. This study examined the correlation between VDR polymorphisms and idiopathic recurrent pregnancy loss. A narrative literature review with a meta-analysis of 85 sources from databases such as PubMed, Web of Science, and Scopus was conducted, focusing on studies from 2020 to 2022. The analysis included studies on vitamin D and miscarriage, adhering to ICD-10 criteria, and VDR gene allele analysis through PCR-RFLP. A comprehensive narrative analysis of the available scientific literature verified the link between comorbidities and vitamin D deficiencies, which can lead to recurrent pregnancy loss by hindering adaptive mechanisms and exacerbating complications. The most researched VDR gene polymorphisms, including FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232), TaqI (rs731236), and Cdx2, are linked to various health issues, particularly reproductive outcomes. The FokI (rs2228570) polymorphism in the VDR gene is a critical predictor of vitamin D levels, influencing pregnancy success. These findings are essential for assessing the risk of idiopathic recurrent pregnancy loss and developing new prevention and treatment approaches.