Relationship between vitamin D receptor gene FokI polymorphism and 25-hydroxyvitamin D levels in apparently healthy Syrians

The vitamin D receptor (VDR) protein has an essential function in regulating serum calcium and 1, 25 dihydroxy vitamin D3. Therefore, variations in VDR gene play an essential role in vitamin D levels. This study aimed to detect the distribution of FokI polymorphism in healthy Syrians and its relation to 25-OH-vitamin D levels. The study included 197 unrelated healthy individuals (Female:131 and Male:66) divided into four groups according to their vitamin D levels: no hypovitaminosis D(G1), vitamin D insufficiency(G2), vitamin D deficiency (G3), and severe vitamin D deficiency (G4). Genotyping for the FokI single nucleotide polymorphism was performed by PCR followed by restriction fragment length polymorphism analysis (RFLP). Frequencies of FF, Ff and ff genotypes were 32.4%, 50% and 17.6%, in G1, 19.6%, 60.8% and 19.6% in G2, 52.1%, 37.5% and 10.4% in G3, and 58%, 37.7% and 4.3% in G4 respectively, with significant differences between the four groups. In conclusion, this study showed a strong correlation between 25-OH-vitamin D levels and FokI polymorphism of the VDR gene in apparently healthy Syrians.