From the Guidelines
Iron deficiency anemia (IDA) is primarily caused by insufficient dietary iron intake, blood loss, or impaired iron absorption, with the most common causes including menstrual blood loss, gastrointestinal bleeding, and malabsorption due to conditions like celiac disease or inflammatory bowel disease. The causes of IDA can be multifactorial, and it is essential to investigate and address the underlying cause to ensure optimal management. According to the British Society of Gastroenterology guidelines 1, approximately a third of men and postmenopausal women presenting with IDA have an underlying pathological abnormality, most commonly in the gastrointestinal tract.
Some of the key causes of IDA include:
- Inadequate dietary iron intake, commonly occurring in vegetarians, vegans, and those with poor nutrition
- Blood loss, particularly in menstruating women with heavy periods, individuals with gastrointestinal bleeding from ulcers, inflammatory bowel disease, or colorectal cancer, and those with frequent blood donations
- Impaired iron absorption due to conditions like celiac disease, Crohn's disease, or gastric bypass surgery
- Increased iron requirements during pregnancy, infancy, and adolescence
- Certain medications like proton pump inhibitors that can reduce iron absorption by decreasing stomach acid
- Chronic inflammation causing functional iron deficiency through hepcidin regulation
- Genetic conditions like hereditary hemorrhagic telangiectasia that can cause chronic bleeding
The most recent and highest quality study on the management of IDA, published in 2024 by the American Gastroenterological Association 1, recommends that treatment typically involves oral iron supplements, addressing the underlying cause, and in severe cases, intravenous iron administration. In patients with inflammatory bowel disease, IV iron appears to be more effective and better tolerated than oral iron, and is recommended as first-line therapy for patients with a hemoglobin level <10 g/dL.
From the Research
Primary Causes of Iron Deficiency Anemia (IDA)
The primary causes of IDA can be categorized into several key areas:
- Blood loss: This includes sources such as heavy periods, childbirth, uterine fibroids, stomach ulcers, colon cancer, and urinary tract bleeding 2.
- Insufficient dietary intake: Poor dietary iron intake is a significant cause, particularly in developing countries where foods with high iron content are scarce 3.
- Decreased iron absorption: This can occur due to intestinal disorders like inflammatory bowel disease or celiac disease, or after surgeries such as gastric bypass 2.
- Increased demand: Physiologically increased iron requirements in children, adolescents, young and pregnant women can also lead to IDA 4.
- Pathological conditions: Chronic inflammatory conditions, including congestive cardiac failure, chronic kidney disease, and inflammatory bowel disease, can contribute to iron deficiency 5, 4.
Other Contributing Factors
Other factors that may contribute to IDA include: