Influence of Vitamin D Status and the VDR Gene Polymorphism on COVID-19 Susceptibility and Outcome

Abstract

Insufficient vitamin D levels in the bloodstream, together with the presence of specific genetic variations known as single nucleotide polymorphisms (SNPs) within the VDR gene, have consistently been linked to a higher likelihood of contracting and experiencing more severe forms of various diseases such as the ongoing COVID-19 pandemic. We aimed to explore the potential relationship between vitamin D levels, Bsml and FoKI polymorphisms, and COVID-19 infection outcomes. A case-control study was conducted with COVID-19 patients and a control group of non-COVID-19 patients (n = 107 each). The associations between vitamin D status, polymorphisms, and COVID susceptibility were investigated. Participants diagnosed with COVID-19 exhibited an average age of 48.84 ± 12.18, while non-COVID-19 patients had an average age of 46.82 ± 9.903. Disease severity, assessed by the CT severity score, showed a negative correlation with the Vitamin D levels. Among participants with COVID-19, the mean level of vitamin D was 35.25 ± 9.40 ng/mL while non-COVID-19 patients showed 38.85 ± 9.40 ng/mL with a significant difference (p = 0.004**) although among COVID-19 cases, 87 (81.3%) individuals had sufficient vitamin D levels and non-severity of disease was more common i.e. 54 (50.5%) among the COVID patients who had sufficient level of Vitamin D. The study found no significant association between Vitamin D levels and rs1544410 Bsml polymorphism (p = 0.429). However, it is important to highlight a weak significant association observed between with Fok1 polymorphism (p = 0.049). These findings underscore the weak influence of genetic factors, particularly VDR Fok1 gene variants, in shaping an individual’s susceptibility to COVID-19. A significant difference in vitamin D status was observed between the COVID-19 and non-COVID-19 groups and lower level was observed in the COVID-19 infected patients. Furthermore, a weak significant association was observed between Fok1 rs2228570 genotype and COVID-19 susceptibility. Larger sample sizes are required to comprehensively understand the association between different genotypes and COVID-19 outcomes.