Background and aim: Although acute upper gastrointestinal bleeding (UGIB) can lead to anemia, evidence regarding the effects of oral iron supplementation on UGIB-induced anemia following discharge remains lacking. The present study aimed to investigate the effects of oral iron supplementation on hemoglobin response and iron storage in patients with anemia secondary to nonvariceal UGIB.

Methods: This randomized controlled trial included 151 patients with nonvariceal UGIB who had anemia at discharge. Patients were assigned to a 1:1 block in which they were either administered 6 weeks of 600 mg/d oral ferrous fumarate (treatment group, n = 77) or treated without iron supplementation (control group, n = 74). The primary outcome was composite hemoglobin response (hemoglobin elevation greater than 2 g/dL or no anemia at the end of treatment [EOT]).

Results: The proportion of patients achieving composite hemoglobin response was greater in the treatment group than in the control group (72.7% vs 45.9%; adjusted risk ratio [RR], 2.980; P = 0.004). At EOT, the percentage change in the hemoglobin level (34.2 ± 24.8% vs 19.4 ± 19.9%; adjusted coefficient, 11.543; P < 0.001) was significantly higher in the treatment group than in the control group; however, the proportions of patients with a serum ferritin level <30 μg/L and a transferrin saturation <16% were lower in the treatment group (all P < 0.05). No significant differences in treatment-associated adverse effects and adherence rates were observed between the groups.

Conclusion: Oral iron supplementation exerts beneficial effects on anemia and iron storage following nonvariceal UGIB without significantly impacting rates of adverse effects or adherence.