Vnitr Lek 2026, 72(5):312-319 | DOI: 10.36290/vnl.2026.059

Iron deficiency anemia: when to use oral versus intravenous iron, how much, and for how long

Veronika Cíglerová, Jan Válka

Ústav hematologie a krevní transfuze, Praha

Iron deficiency anemia is the most common hematologic disorder and its management requires accurate diagnosis as well as a rational choice of iron replacement strategy. The decision between oral and intravenous therapy is based on the patient's clinical status, the etiology of iron deficiency, and the expected absorption of iron. Oral preparations at a dose of 100-200 mg of elemental iron daily represent first-line treatment in stable patients; with an adequate response, an increase in hemoglobin of ≥ 10 g/L can be expected within 2 weeks, and therapy should continue for at least 3 months after normalization to replenish iron stores. Intravenous iron is indicated in cases of intolerance, insufficient response, impaired absorption, or the need for rapid correction. Red blood cell transfusion is reserved for hemodynamically unstable or severely symptomatic patients and does not replace subsequent iron supplementation.

Keywords: iron deficiency anemia, iron deficiency, oral iron, intravenous iron, iron replacement therapy.

Accepted: August 20, 2026; Published: August 27, 2026  Show citation