The effects of serum levels, and alterations in the genes of binding protein and receptor of vitamin D on gastric cancer

Due to many biological cell functions of vitamin D including regulation of cell survival, proliferation and differentiation, the metabolism of itself gains importance in the development of several types of cancer. This case–control study was designed to evaluate the risk of gastric cancer development in terms of VDR rs2228570 & rs731236, and VDBP rs7041 polymorphisms, and serum levels of vitamin D. The study consists of 77 gastric cancer patients and 84 healthy individuals. VDR and VDBP gene polymorphisms and vitamin D levels were determined by using PCR–RFLP and HPLC methods. The distribution of VDR or VDBP gene variants were not different in study groups. The serum level of 25-hydroxyvitamin D was significantly lower in gastric cancer patients versus controls (16 ± 6 → 11 ± 6 ng/ml) in which male patients have higher levels than females. Although the whole study population lacks normal levels of 25-hydroxyvitamin D, it was found that the risk of the development of gastric cancer was approximately fourfold higher in cases with severe vitamin D (< 10 ng/ml) deficiency. Our results indicate that VDR rs731236 & rs2228570 or VDBP rs7041 polymorphisms were not risk factors for the development of gastric cancer individually, however, lower serum levels of vitamin D may be a contributory risk for both predisposition and development of gastric cancer.