B-12 and the stomach

Stomach problems can contribute to a B12 deficiency in two ways.

First, irritation and inflammation of the stomach can prevent the stomach cells from functioning properly. When functioning improperly, the cells may stop producing a substance required for B12 absorption called intrinsic factor (IF). Without IF, B12 cannot be absorbed from the gastrointestinal tract into the body's cells.

A second way for stomach problems to create B12 deficiency is through inadequate secretion of stomach acids. Lack of stomach acids (a condition called called hypochlorhydria) gets in the way of B12 absorption since most B12 in food is attached to proteins in the food, and stomach acids are necessary to release the B12 from these proteins.