Effect of the oral administration of vitamin B12 to patients under distal and total gastrectomy

Abstract

Objectives: At high dosage, orally administered vitamin B12 is absorded by a gradient of concentration, not by an intrinsic factor. We studied the effect of oral administration of Mecobalamin (Methicobal) to patients undergoing distal and total gastrectomy. Methods: Eleven patients undergoing distal gastrectomy B-1 and 8 total gastrectomy R-Y were orally administered 1.5 mg/day of Mecobalamin, devided into 3 times/day, for 4 weeks. Blood levels of vitamin B12 were measured. Results: In distal gastrectomy, blood levels of vitamin B12, preceding and after 2 and 4 weeks administration of Mecobalamin, were 412+ / -33, 581+ / -62, and 701+ / -94 pg/ml. In total gastrectomy, they were 312+ / -40, 440+ / -34, and 469+ / -30 pg/ml. Oral Mecobalamin administration increased vitamin B12 blood levels in patients undergoing both types of surgery. The correlation between the vitamin B12 blood levels before administration and increasing vitamin B12 after 4 weeks of administration was a significant positive correlation in distal gastrectomy but tended to be negative in total gastrectomy. Conclusion: Oral Mecobalamin administration at the usual dosage effectively provided patients undergoing distal and total gastrectomy with vitamin B12 and easily controlled at the clinic.