From the Guidelines
Iron deficiency anemia is primarily caused by chronic blood loss, poor dietary intake, and malabsorption of dietary iron, with approximately a third of men and postmenopausal women presenting with IDA having an underlying pathological abnormality, most commonly in the GI tract. The causes of iron deficiency anemia (IDA) can be multifaceted, including:
- Poor dietary intake of iron-rich foods like red meat, poultry, fish, beans, and leafy greens 1
- Malabsorption of dietary iron due to gastrointestinal conditions such as celiac disease, inflammatory bowel disease, or after gastric surgery 1
- Chronic blood loss from heavy menstrual periods in women, gastrointestinal bleeding (from ulcers, polyps, or colorectal cancer), or regular use of medications like aspirin or NSAIDs that can cause internal bleeding 1
- Pregnancy, which increases iron requirements and can lead to deficiency if not supplemented properly
- Certain populations are at higher risk, including infants and young children, teenage girls, women of childbearing age, and frequent blood donors
It is essential to investigate the underlying cause of IDA, especially in adults with a new diagnosis of IDA without an obvious explanation, as it may be a presenting manifestation of colonic or oesophago-gastric carcinoma 1. The management of IDA requires iron replacement therapy (IRT) in combination with appropriate investigation to establish the underlying cause, and bidirectional GI endoscopy is the standard diagnostic approach to examination of the upper and lower GI tract 1.
From the Research
Causes of Iron Deficiency Anemia (IDA)
The causes of IDA can be categorized into several groups, including:
- Blood loss: This is a common cause of IDA, particularly in men and postmenopausal women, often due to lesions in the gastrointestinal tract 2.
- Increased demand: IDA can occur during periods of rapid body growth, such as infancy and puberty, due to increased requirements for iron 3.
- Insufficient dietary intake: A poor dietary iron intake is a common cause of IDA, especially in developing countries where foods with high iron content are scarce 4, 5.
- Disorders affecting iron absorption: Certain conditions, such as atrophic gastritis, Helicobacter pyli infection, and celiac disease, can lead to impaired iron absorption and IDA 6, 4.
- Physiological situations: IDA can also occur in physiological situations that increase requirements for iron, such as pregnancy and adolescence 5.
Specific Causes
Some specific causes of IDA include:
- Gastrointestinal malignancy: This is a common cause of IDA in men and postmenopausal women, and gastrointestinal evaluation is often indicated to exclude this possibility 2.
- Chronic kidney disease: IDA is common in patients with chronic kidney disease, and diagnosis and treatment may need to incorporate transferrin saturation 6.
- Chronic heart failure: IDA can occur in patients with chronic heart failure, and high-dose intravenous iron formulations may be beneficial in these cases 6.
- TMPRSS6 mutations: Iron-refractory iron deficiency anemia can develop as a consequence of these mutations, although this is a rare occurrence 6.