Introduction & Objectives: Vitamin D receptor (VDR), which is involved in regulating cell growth and proliferation, may contribute to the development of colorectal cancer. Polymorphisms in the VDR gene may influence the expression or function of the VDR protein. The purpose of this study was to examine the association between the polymorphism and colorectal cancer.

Materials & Methods: In this case-control study, the association between VDR polymorphism and colorectal cancer in 130 patients and 130 controls was evaluated. PCR-RFLP technique was used to determine the genotypes.

Results: The frequencies of the CC, CT, and TT genotypes were 10%, 31.5%, 58.5% in healthy controls and 15.4%, 37.7% and 65.8% in colorectal cancer patients, respectively. We observed the T allele in 60.7%, 65.8%, and the C allele in 39.3% and 34.2% of the control group and colorectal cancer patients. We could find significant association between the CT genotype and colorectal cancer (P=0.005 CI=95% 0.257-0.783 OD=0.449) while there was not any association between the CC genotype and colorectal cancer P=0.992, CI=95% 0.433-2.289, OD=0.996.

Conclusion: Based on our finding, interestingly we could detect a reverse association between genotype 61968T>C and colorectal cancer. But we could not find any significant association between CC genotype and colorectal cancer. Our study corroborates the findings of the previous studies regarding lack of association between the CC genotype and colorectal cancer.