Why can gastric atrophy be associated with iron-deficiency anemia?

Gastric atrophy is a condition characterized by the thinning of the stomach mucosa and a partial loss of glandular and secreting cells. This condition can be associated with iron-deficiency anemia primarily because the stomach's production of acid is essential for efficient iron absorption.12

Under normal physiological conditions, stomach acid helps prevent the formation of insoluble iron complexes, thereby facilitating the absorption of iron in the duodenum. When gastric atrophy occurs, the resulting impairment of the stomach's secretory functions—specifically the inhibition or reduction of acid secretion—impedes this process, making it difficult for the body to absorb sufficient iron from the diet. Consequently, this reduced absorption capacity can lead to the development of iron-deficiency anemia.21