According to medical research , when vitamin b12 enters the body , it forms a compound with an intrinsic factor secreted by the parietal cells large cells of the peptic glands on the gastric mucosa mucous membrane of the stomach , before being absorbed by receptors in the ileum lower part of the small intestine in the presence of calcium ions 在維他命b12的吸收方面,根據(jù)醫(yī)學報導,維他命b12在吃進人體后,首先會在胃部,和胃壁細胞parietal cells分泌的一種蛋白質(zhì)內(nèi)因子intrinsic factor結(jié)合,形成復(fù)合物后,再由小腸段中的回腸ileum吸收。在回腸之接受體receptors吸收時,需要有鈣離子之存在。