Enteral Vitamin B12 Supplementation Is Effective for Improving Anemia in Patients Who Underwent Total Gastrectomy.

Background: This study aimed to investigate the efficacy of enteral supplementation of vitamin B12 for vitamin B12 deficiency in patients who underwent total gastrectomy for gastric cancer.

Methods: The study enrolled 133 patients who underwent total gastrectomy for gastric cancer at Kochi Medical School. Clinical data were obtained to investigate associations between vitamin B12 supplementation and vitamin B12 levels. Vitamin B12 deficiency was defined as serum vitamin B12 less than 200 pg/mL. Baseline characteristics and changes in hematological variables, including vitamin B12 levels, were examined.

Results: Vitamin B12 deficiency was present in 71.4% of the 133 patients. Vitamin B12 levels at 3, 6, and 12 months after enteral supplementation were 306 pg/mL, 294 pg/mL, and 367 pg/mL, respectively, which were all significantly higher than those before supplementation (p < 0.001 for all comparisons). The median red blood cell count at 3, 6, and 12 months after enteral supplementation were 380 × 104/mm3, 394 × 104/mm3, and 395 × 104/mm3, respectively, which were all significantly higher than those before supplementation (p = 0.020, p = 0.001, and p = 0.003, respectively). Vitamin B12 levels at 3, 6, and 12 months after supplementation were significantly higher in patients supplemented enterally than those supplemented parenterally (p < 0.001 for all comparisons).

Conclusions: Vitamin B12 deficiency was found in 71.4% of postoperative patients who underwent total gastrectomy for gastric cancer, and enteral vitamin B12 supplements might be effective to improve anemia in these patients.