Vitamin B12 deficiency after total gastrectomy for gastric cancer, prevalence, and symptoms: a systematic review and meta-analysis

Purpose Nutrient deficiency is one of the common complications in patients who undergo gastrectomy, especially those vitamins and minerals absorbed in the stomach or by substances in the gastric juice, such as vitamin B12. Hence, this systematic review and meta-analysis were conducted for the first time to investigate the prevalence of vitamin B12 deficiency and its symptoms in gastric cancer (GC) patients who underwent gastrectomy. Method PubMed, Scopus, Google Scholar, and Web of Science databases were searched to find related studies. After screening, studies were selected based on the abstract and title of related studies. The heterogeneity and inconsistency between studies were evaluated using Cochran’s Q, I 2 tests. Egger’s test analyzed publication bias for studies. A 95% confidence interval (95% CI) was used to estimate the overall prevalence of vitamin B12 deficiency. Results Fourteen studies, including 2627 GC patients who underwent surgery, were included in the study. The mean age of the patients in this study was 61.2 ± 4.93 years. The pooled estimate of meta-analysis results showed that the prevalence of vitamin B12 deficiency after gastrectomy in patients with GC was 48.8% (95% CI:32.4, 65.2%, I 2 : 98.85, τ 2 = 0.05, Q (13) = 1127.8, P < 0.001). The most important symptoms were anemia, fatigability, cold feet or legs, numbness, and dizziness. Conclusion and recommendation Vitamin B12 deficiency has a high prevalence among patients who have undergone gastrectomy, and it is necessary to pay enough attention to treating these patients after surgery to prevent its complications.