Genetic insights into vitamin D deficiency: a case-control study of GC and CYP24A1 gene polymorphism.

Despite the sunny climate, vitamin D deficiency is highly prevalent in several parts of the world. Several risk factors are associated with VD deficiency, including single nucleotide polymorphism and post-translational modifications in its transport protein, known as vitamin D binding protein (DBP) or GC and CYP24A1, a protein associated with its degradation. Our study explores the impact of rs4588 and rs7041 in the GC gene, along with CYP24A1 rs4809960 and rs2585428, on serum vitamin D and the risk of vitamin D insufficiency. This study enrolled 114 healthy controls and 239 vitamin D-deficient subjects. SNPs were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The G/T genotype of D432E and the A/A genotype of T436K in the GC gene were observed to be risk factors for vitamin D deficiency. Overall, a significant (P < 0.05) association was observed between the D432E and T436K polymorphism and vitamin D deficiency. Polymorphic genotypes of CYP24A1 rs4809960 and rs2585428 polymorphisms were significantly associated with a higher risk of Vitamin D deficiency. D432E and T436K polymorphisms were associated with decreased vitamin D and increased PTH levels in vitamin D-deficient individuals. Similarly, both CYP24A1 polymorphisms were significantly associated with a higher risk of vitamin D deficiency. Also, a negative association was observed between sufficient serum levels of 25-hydroxyvitamin D and PTH levels.