二甲双胍是治疗 2型糖尿病的重要药物 ,但有1 0 %～ 30 %的用药者出现维生素Ｂ12 吸收不良 ,有关其机制目前尚有争论。有研究认为是由于二甲双胍通过延迟食物吸收而改变了肠道动力和 (或 )促进细菌生长所致。但因回肠粘膜细胞Ｂ12 内因子的摄取是钙依赖性的 ,而二甲双胍可影响 Metformin is an important drug for the treatment of type 2 diabetes, but 10% to 30% of the patients have vitamin B12 malabsorption. There are controversies about its mechanism. Some studies suggest that metformin changes intestinal motility by retarding food absorption and / or promoting bacterial growth. However, uptake of B12 by ileal mucosal cells is calcium-dependent, and metformin can affect