Surgical removal of a part of stomach resulted in disturbed absorption of vitamin B12, it is excreted with feces. The patient was diagnosed with anemia. What factor is necessary for absorption of this vitamin?

Answer options

1. Gastrin
2. Folic acid
3. Pepsin
4. Hydrochloric acid
5. Gastromucoprotein

Explanation

Resection of forestomach causes (intrinsic factors) vitamin B12 deficiency leading to megalocytic, macrocytic anemia. Resection of the pyloric part of the stomach causes iron deficiency leading to microcytic anemia. Absorption of Vitamin B12 takes place in the stomach when it has the castle's intrinsic factor (gastromucoprotein) produced by the parietal's cells in the stomach.