Objective: This meta-analysis aimed to assess the association between vitamin B6 intake, blood PLP levels, and the risk of colorectal cancer.
Methods: The databases PubMed, Cochrane Library and Embase databases were comprehensively searched for cohort studies or case-control studies. The odds ratio (OR) and 95% confidence interval (CI) were extracted from each eligible study, and the statistical software Stata was used to perform statistical merging.
Results: Twenty-eight studies (20 cohort studies, 8 case-control studies) were included in our meta-analysis. The combined OR for the association between colorectal cancer risk and vitamin B6 intake was 0.80 (95% CI: 0.68-0.94), while the combined OR between blood PLP levels and colorectal cancer risk was 0.54 (95% CI: 0.35-0.84). In addition, the subgroup analysis revealed that vitamin B6 could reduce the risk of colorectal cancer in women [vitamin B6 intake OR = 0.79, 95% CI (0.65-0.96); blood PLP levels OR = 0.41, 95% CI (0.30-0.57)] and also reduce the risk of colon cancer in men and women [vitamin B6 intake OR = 0.76, 95% CI (0.64-0.91); blood PLP levels OR = 0.56, 95% CI (0.42-0.73)].
Conclusion: In this meta-analysis, vitamin B6 intake and blood PLP levels were inversely associated with colorectal cancer risk.