Iron Deficiency Anemia Causes and Management

Common Causes of Iron Deficiency Anemia

Gastrointestinal bleeding is the most common cause of iron deficiency anemia in men and postmenopausal women, potentially indicating serious conditions like colorectal or gastric cancer 2, 3
Menstrual bleeding is the leading cause of iron deficiency anemia in premenopausal women 3, 4
Angioectasias can cause small-bowel bleeding, leading to chronic iron loss 1, 5
Portal hypertensive gastropathy causes chronic gastrointestinal blood loss in patients with liver disease 1, 6
Gastric antral vascular ectasia (GAVE) is a source of chronic bleeding 1, 5

Celiac disease impairs duodenal iron absorption 1
Inflammatory bowel disease causes both malabsorption and blood loss 1, 7
Post-bariatric surgery, particularly procedures that bypass the duodenum and proximal jejunum, can lead to iron deficiency 7, 6
H. pylori infection interferes with iron absorption 1, 8

Iron deficiency affects 39% of premenopausal women and 8% of postmenopausal women in the US 1, 8
1-4% of men have iron deficiency, with 2% having iron deficiency anemia 1, 8

Serum ferritin is the most powerful test for iron deficiency; levels <45 μg/dL indicate iron deficiency in anemic patients 1, 8
In inflammatory conditions, ferritin may be elevated (usually <100 μg/dL) despite iron deficiency 1, 8

Intravenous iron therapy is indicated for inflammatory bowel disease with active inflammation 1, 7
Intravenous iron therapy is indicated for post-bariatric surgery patients 6
Intravenous iron therapy is indicated for patients with ongoing blood loss 6
Disease-specific management, such as treating underlying inflammation and considering IV iron, is necessary for inflammatory bowel disease 1, 7
Portal hypertensive gastropathy requires starting with oral iron and considering nonselective β-blockers and IV iron if unresponsive 1, 6

All men and postmenopausal women with iron deficiency anemia should undergo bidirectional GI endoscopy to exclude malignancy 2, 3
Treating both the underlying cause and the iron deficiency itself is necessary for optimal outcomes 3
Consider multidisciplinary management including gastroenterologists, hematologists, and nutritionists in complex cases 1, 8