From the Guidelines
The workup for iron deficiency anemia should begin with a complete blood count (CBC) to confirm anemia and assess the severity, followed by iron studies including serum ferritin, serum iron, total iron binding capacity (TIBC), and transferrin saturation, as recommended by the British Society of Gastroenterology guidelines 1. The diagnosis of iron deficiency anemia is typically made by laboratory tests, including a low ferritin level (below 45 ng/mL) 1. Additional tests should include a peripheral blood smear to evaluate red cell morphology, reticulocyte count to assess bone marrow response, and hemoglobin electrophoresis if thalassemia is suspected. Once iron deficiency is confirmed, the underlying cause must be identified. For premenopausal women, heavy menstrual bleeding is a common cause, while in men and postmenopausal women, gastrointestinal blood loss should be investigated with upper endoscopy and colonoscopy, as suggested by the British Society of Gastroenterology guidelines 1. Other tests may include:
- Celiac disease screening
- Helicobacter pylori testing
- Urinalysis Nutritional assessment is important in all patients. Treatment involves oral iron supplementation (ferrous sulfate 325 mg three times daily or ferrous gluconate 300 mg twice daily), taken on an empty stomach with vitamin C to enhance absorption. Intravenous iron may be necessary for patients with malabsorption, intolerance to oral iron, or severe anemia. Follow-up should include monitoring hemoglobin levels after 2-4 weeks of treatment, with expected increases of 1-2 g/dL per month until normal levels are achieved. The American Gastroenterological Association (AGA) recommends bidirectional endoscopy for asymptomatic postmenopausal women and men with iron deficiency anemia, and suggests bidirectional endoscopy for asymptomatic premenopausal women with iron deficiency anemia 1.
From the Research
Workup for Iron Deficiency Anemia
- The workup for iron deficiency anemia typically involves a combination of laboratory tests and physical examination 2, 3, 4.
- A complete blood count (CBC) is often the initial test, which can provide clues to the classification and cause of anemia 2, 3, 4.
- CBC parameters such as red blood cell (RBC) count, hematocrit, mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) can be used to diagnose iron deficiency anemia 2.
- However, CBC alone may not be sufficient to diagnose iron deficiency, and additional tests such as serum ferritin, iron levels, and total iron-binding capacity may be necessary 3, 4.
- A peripheral blood smear, reticulocyte count, and levels of vitamin B12, folate, lactate dehydrogenase, haptoglobin, and bilirubin may also be included in the workup for anemia 4.
- It is essential to note that iron depletion can quickly develop into iron deficiency anemia if not detected early, emphasizing the importance of accurate diagnosis and monitoring 3.
Laboratory Tests
- Serum ferritin is a key test for diagnosing iron deficiency, with levels <30 µg/L indicating iron deficiency 2.
- Hemoglobin and hematocrit levels can also be used to diagnose iron deficiency anemia, with levels <120 g/L and <35.5% indicating anemia 2.
- MCV, MCHC, and MCH can be used to differentiate between iron deficiency anemia and other types of anemia 2.