Vitamin B1 Intake and the Risk of Colorectal Cancer: a Systematic Review of Observational Studies.

Colorectal cancer is the main leading cause of death from cancer worldwide. Protective effects of vitamin B1 on colorectal cancer have been observed in some epidemiological studies. A systematic review and meta-analysis of observational studies evaluated the association of intake of vitamin B1 with the incidence of colorectal cancer. Relevant studies were identified in MEDLINE via PubMed (published up to September 2020). We extracted data from articles on vitamin B1 and used a multivariable-adjusted odds ratio (OR) and a random-effects model for analysis. We found seven articles meeting the inclusion criteria (1 of cohort studies and 6 case-control studies) and a total of 6,184 colorectal cancer cases were included in this meta-analysis. The multivariable-adjusted OR for pooled studies for the association of roughly the same high dose level versus the lowest vitamin B1 intake and the risk of colorectal cancer was 0.76 (95% confidence interval ([95%CI]: 0.65, 0.89). This meta-analysis studied the relationship between vitamin B1 and colorectal cancer. We found vitamin B1 intake was inversely associated with the risk of colorectal cancer. However, further research and large sample studies need to be conducted to better validate the result.