Some recent reports have noted that can occur in patients who have undergone bariatric surgery, such as Roux-en-Y (RY) gastric bypass or biliopancreatic diversion, or in patients who receive enteral nutrition through a jejunostomy. No reports appear to have assessed the serum state of patients following gastrectomy with RY reconstruction for .A cross-sectional study was conducted from June 2013 to December 2014. Serum levels () in 242 out-clinic patients who underwent curative gastrectomy were obtained. Patients were classified into an RY group (n = 208) and a non-RY group (n = 34).was identified in 3 patients in the RY group (1.4%), and 2 patients in the non-RY group (5.9%; p = 0.146), but none experienced any symptoms caused by . No significant difference in the mean was seen between the RY group (105.8 ± 21.2 08g/dl) and non-RY group (107.9 ± 22.7 08g/dl; p = 0.499). In the RY group, the mean was significantly lower in younger patients, patients with follow-up period