Vitamin B₆ Intake and the Risk of Colorectal Cancer: A Meta-Analysis of Prospective Cohort Studies

ABSTRACT

Objectives: We performed this meta-analysis to estimate the association between vitamin B₆ intake and colorectal cancer risk. Methods: Prospective cohort studies on vitamin B₆ intake and colorectal cancer risk were identified by searching databases from the period of 1960 to 2016. Results from individual studies were synthetically combined using Stata 13.0 software. Results: A total of 10 prospective cohort studies including 13 data sets were included in our meta-analysis, containing 7,817 cases and 784,550 subjects. The combined relative risks (RR) of colorectal cancer for the highest vitamin B₆ intake compared with the lowest vitamin B₆ intake was 0.88 [95% confidence intervals (CIs): 0.77–1.02]. Dose-response meta-analysis based on five eligible studies showed that for each additional 3 and 5 mg of vitamin B₆ intake, the risk would decrease by 11% (RR: 0.89, 95%CI: 0.81–0.98) and 17% (RR: 0.83, 95%CI: 0.71–0.97), respectively. Little evidence of publication bias was found. Conclusion: This meta-analysis provides evidence of a nonsignificant decrease in colorectal cancer risk associated with the high level of vitamin B₆ intake, but the risk in dose-response analysis is significant. However, the latter finding is based on a limited number of studies, which should be interpreted with caution.

Declaration of Interest

All the authors declare that they have no conflict of interest.

Acknowledgments

The authors would like to acknowledge all authors of the original studies that were included in this meta-analysis.