FokI Polymorphism of the VDR Gene Is Associated with Vitamin D Insufficiency in Elite Male Power Athletes of Kazakhstan.

Background/Objectives: We aimed to investigate the association between VDR gene variants and vitamin D levels in elite male power athletes of Kazakhstan. Methods: We recruited 92 elite male power athletes of Kazakhstan. Concentrations of serum 25(OH)D were measured with the Access 25(OH) Vitamin D Total Assay on the Unicel Dxl 800 Access Immunoassay System. Gene polymorphisms were determined by a real-time polymerase chain reaction (RT-PCR) allelic discrimination assay using TaqMan™ probes. Results: Vitamin D insufficiency was registered in 63% of athletes. Age (χ2 = 6.83, p < 0.01), BMI (χ2 = 6.83, p < 0.01), and sport experience (χ2 = 4.44, p < 0.04) showed a statistically significant association with vitamin D insufficiency and deficiency (age, χ2 = 7.93, p < 0.01; BMI, χ2 = 5.11, p < 0.03; sport experience, χ2 = 6.19, p = 0.01). The A/A genotype of the VDR FokI polymorphism (rs2228570) showed a strong correlation with vitamin D insufficiency (G/G-G/A vs. A/A, OR = 9.25, 95% CI = 2.01-42.51, p < 0.01) but not deficiency. Conclusions: Our study reveals a significant prevalence of vitamin D insufficiency and deficiency among elite male power athletes of Kazakhstan. Age, BMI, and sport experience are essential factors in developing personalized strategies to address vitamin D insufficiency. The A/A genotype of the VDR FokI polymorphism can be used as a potential biomarker for vitamin D inadequacy in elite male power athletes of Kazakhstan.