Abstract
Background: Few studies have investigated vitamin B12 deficiency caused by the reduction of intrinsic factors after gastrectomy and replacement therapy in detail. Methods: 1）We examined the relationship between serum vitamin B12 levels and the postoperative period in patients after gastrectomy. 2）Patients with low serum vitamin B12 levels were orally administered mecobalamin to evaluate its efficacy. 3）Serum vitamin B12 levels in patients undergoing total gastrectomy were measured preoperatively and one year after surgery. Results：Serum vitamin B12 levels were low in more than 70％of patients within 5 years after total gastrectomy. Oral administration of mecobalamin improved serum vitamin B12 levels. After total gastrectomy, serum vitamin B12 levels decreased below the standard one year after surgery. Conclusion: After gastrectomy, serum vitamin B12 levels decrease early, and it is important to assess and administer replacement therapy. Oral administration of mecobalamin is effective and easy to control.
