Association between Vitamin B6 and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Epidemiological Studies

Inconsistent findings have emerged from epidemiological research investigating the association between vitamin B-6 and the risk of gastric cancer. To obtain a more precise assessment, we conducted a comprehensive search of published data and performed a meta-analysis. PubMed, Web of Science, EMBASE and Cochrane Library databases were systematically searched. A total of 12 studies (5 prospective cohort and 7 case-control studies) involving 5,692 cases and 814,157 participants were included in the meta-analysis. The results showed that high intake of vitamin B-6 may reduce the odds of gastric cancer (OR = 0.83, 95% CI: 0.73-0.95, p = 0.006). However, this association was only observed in the case-control studies (OR = 0.68, 95% CI: 0.51-0.89, p = 0.006) but not in the cohort studies (RR = 1.01, 95% CI: 0.94-1.08, p = 0.819). Additionally, the negative association between vitamin B-6 intake and gastric cancer risk was found in the United States of America (OR = 0.71, 95% CI: 0.62-0.82, p = 10(-4)), but not in Europe (OR = 0.88, 95% CI: 0.74-1.05, p = 0.169) or the other regions (OR = 0.86, 95% CI: 0.66-1.13, p = 0.280). In conclusion, there is not sufficient evidence to assume that vitamin B-6 intake is associated with gastric cancer risk, which needs further confirmation.

Automated summary

A meta-analysis of 12 studies shows that high intake of vitamin B-6 may reduce the risk of gastric cancer. However, this association is only observed in case-control studies, not in cohort studies. Furthermore, the association is confirmed in the United States but not in Europe or other regions.