Abstract
Vitamin D plays a crucial role in bone health and immune function, with serum 25(OH)D levels influenced by genetic, dietary, and metabolic factors. BACKGROUND/OBJECTIVES: This study investigated the impact of VDR rs731236, CYP2R1 rs10741657, and GC rs2282679 polymorphisms, body mass index (BMI), and dietary vitamin D intake on vitamin D status. METHODS: A total of 230 adults were classified into four BMI categories: normal weight (NW), overweight (OW), obesity class I (OB), and obesity class II/III (OP). Participants completed a Food Frequency Questionnaire (FFQ) and a 7-day Food Frequency Diary (FFD). Genotyping was performed using TaqMan assays, and serum 25(OH)D was quantified via spectrophotometry. Statistical analyses included ANOVA and multiple linear regression. RESULTS: The VDR rs731236 CC genotype, CYP2R1 rs10741657 AG/GG, and GC rs2282679 AC/CC were associated with lower serum vitamin D levels. A higher BMI was significantly correlated with reduced serum 25(OH)D (p < 0.001), with BMI emerging as the strongest predictor of vitamin D status. FFQ-based dietary intake showed a modest positive correlation with 25(OH)D (r = 0.47, p < 0.001). CONCLUSIONS: BMI and genetic variants in VDR, CYP2R1, and GC significantly influence vitamin D metabolism. Personalized interventions addressing genetic predispositions and weight management may improve vitamin D status.