Effect of vitamin D receptor gene TaqI polymorphism on vitamin D levels and biochemical, inflammatory, and oxidative stress markers in individuals with obesity

Abstract Obesity, characterized by excessive accumulation of body fat, is associated with reduced vitamin D levels. Several polymorphisms of the vitamin D receptor exist, such as TaqI (rs731236), although their association with obesity remains inconsistent. The aim of this study was to evaluate the effect of TaqI polymorphism on biomarkers in individuals with obesity. The study has been approved by the Research Ethics Committee of the Federal University of Pampa (UNIPAMPA), under approval number 5.308.525. A total of 275 individuals were included in the study, divided into groups according to Body Mass Index: eutrophic, overweight, and individuals with obesity. Blood samples and anthropometric data were collected for analysis and 246 individuals were genotyped for the VDR gene TaqI polymorphism. Results showed that vitamin D levels were higher in individuals with CC genotype compared with those with TT genotype. A decrease in biochemical parameter levels was observed in the obesity group. In contrast, inflammatory and oxidative stress markers were increased in the overweight and obesity groups. Additionally, TBARS, IL-8, IL-10, and CRP were identified as independent risk factors for obesity, where vitamin D was identified as an independent protective factor. Although TaqI polymorphism was not an independent risk factor for obesity, our results emphasize the relevance of inflammatory and oxidative stress biomarkers in obesity risk assessment. Moreover, the modulation of vitamin D levels by genotype reinforces its potential as a target for preventive and therapeutic interventions due to its protective role.