These cells are located in the gastric glands found in the lining of the fundus and body regions of the stomach.

Parietal cells are primarily regulated via histamine, acetylcholine and gastrin signalling from both central and local modulators.

A long-term deficiency in vitamin B12 can lead to megaloblastic anemia, characterized by large fragile red blood cells.

Pernicious anaemia results from autoimmune destruction of gastric parietal cells, precluding the synthesis of intrinsic factor and, by extension, absorption of vitamin B12.

Atrophic gastritis, particularly in the elderly, will cause an inability to absorb B12 and can lead to deficiencies such as decreased DNA synthesis and nucleotide metabolism in the bone marrow.