Association between Vitamin B₁₂ and Risk of Gastric Cancer: A Systematic Review and Meta-Analysis of Epidemiological Studies

Abstract

Epidemiological studies focusing on the association between vitamin B₁₂ and gastric cancer risk reported inconsistent findings. We conducted a systematic review and meta-analysis to assess the relationship. PubMed (Medline), Web of science and EMBASE databases were systematically searched. A total of nine studies involving 3,494 cases of with gastric cancer and 611,638 participants were included. The result showed that there is no significant association between vitamin B₁₂ intake and the risk of gastric cancer (OR = 0.88, 95% CI: 0.69-1.12, P = 0.303). Nevertheless, high intake of vitamin B₁₂ might decrease the risk of gastric cancer in Helicobacter pylori (Hp)-negative people (OR = 0.83, 95% CI: 0.62-0.99, P = 0.044), but increase the cancer risk in Hp-positive populations (OR = 1.66, 95% CI: 1.27-2.16, P = 10⁻⁴). Additionally, further analysis indicated that excessive vitamin B₁₂ might increase the risk of non-cardia gastric cancer (OR = 1.15, 95% CI: 1.01-1.33, P = 0.006). A negative association between vitamin B₁₂ intake and gastric cancer risk was found in nonsmokers (OR = 0.83, 95% CI: 0.71-0.96, P = 0.012) but not in smokers (OR = 1.08, 95% CI: 0.71-1.47, P = 0.619). In conclusion, although we found no convincing evidence that vitamin B₁₂ intake is associated with the risk of gastric cancer, it is important to maintain the relative stability of vitamin B₁₂ for people with Hp infection.

Acknowledgments

We thank Editage of Cactus Communications for the English language editing of the article.

Compliance with Ethical Standards

Disclosure of potential conflicts of interest

Conflict of Interest

The authors declare that they have no conflict of interest.

Ethical Approval

For this type of study formal consent is not required.

Informed Consent

Informed consent was obtained from all individual participants included in the study.

Author Contributions

Chang H, He JB and Fu HJ developed the study concept, designed the study, conducted the electronic searches and wrote the draft of the manuscript. He JB, Fu HJ, Li CC and Deng ZH conducted validity assessment, data extraction and provided critical review of the manuscript. He JB and Fu HJ tabulated data and conducted meta-analyses. All authors read and approved the final manuscript.

Additional information

Funding

This study was supported by Postgraduate mentor team-building program of Southwest University (XYDS201905).