ABSTRACT
BACKGROUND: A systematic review and meta-analysis of observational studies evaluated the association of intake of vitamin B2 with the incidence of colorectal cancer. MATERIALS AND METHODS: Relevant studies were identified in MEDLINE via PubMed (published up to April 2014). We extracted data from articles on vitamin B2 and used multivariable-adjusted odds ratio (OR) and a random-effects model for analysis. RESULTS: We found 8 articles meeting the inclusion criteria (4 of cohort studies and 4 of case-control studies) and a total of 7,750 colorectal cancer cases were included in this meta-analysis. The multivariable-adjusted OR for pooled studies for the association of the highest versus lowest vitamin B2 intake and the risk of colorectal cancer was 0.83 (95% confidence interval [95%CI]:0.75,0.91). We performed a sensitivity analysis for vitamin B2. If we omitted the study by Vecchia et al., the pooled OR was 0.86 (95%CI, 0.77,0.96). CONCLUSIONS: This is the first meta-analysis to study links between vitamin B2 and colorectal cancer. We found vitamin B2 intake was inversely associated with risk of colorectal cancer. However, further research and large sample studies need to be conducted to better validate the result.