Duration of Iron Therapy for Iron Deficiency Anemia

Iron therapy should be continued for three months after correction of anemia to replenish iron stores. 1

General Principles of Iron Therapy Duration

Iron supplementation should continue until both hemoglobin levels normalize and iron stores are replenished 1
The goal of treatment is to restore hemoglobin levels and mean corpuscular volume (MCV) to normal range and replenish body iron stores 1
Once anemia is corrected, iron therapy should be maintained for an additional three months to ensure adequate replenishment of iron stores 1
After successful treatment, hemoglobin concentration and red cell indices should be monitored at regular intervals - recommended every three months for one year and then after a further year 1

Continue oral iron supplementation for three months after normalization of hemoglobin to replenish iron stores 1
Oral iron is typically administered at doses of 60-120 mg elemental iron per day depending on severity 1
No more than 100 mg elemental iron per day is recommended for patients with inflammatory bowel disease (IBD) 1
Additional oral iron should be given if hemoglobin or MCV falls below normal during follow-up 1

Start with low-dose (30 mg/day) oral iron supplements at first prenatal visit 1
For treatment of established anemia during pregnancy, prescribe 60-120 mg/day of iron 1
When hemoglobin concentration normalizes for the stage of gestation, decrease the dose to 30 mg/day 1

After successful treatment of iron deficiency anemia with intravenous iron, re-treatment should be initiated as soon as serum ferritin drops below 100 μg/L or hemoglobin below 12 g/dL (women) or 13 g/dL (men) 1
Patients should be monitored for recurrent iron deficiency every 3 months for at least a year after correction, and between 6 and 12 months thereafter 1
Post-treatment serum ferritin levels of >400 μg/L better prevented recurrence of iron deficiency within 1-5 years compared to lower levels 1

Iron treatment should be limited to patients on chemotherapy 1
After chemotherapy completion, erythropoiesis-stimulating agent (ESA) therapy should be discontinued (roughly 6-8 weeks after the last dose of chemotherapy) 1
For patients with functional iron deficiency (TSAT <20% and serum ferritin >100 ng/mL), a dose of 1000 mg iron should be given according to available IV iron formulations 1

After normalization of hemoglobin, monitor hemoglobin concentration and red cell indices every three months for one year, then after another year 1
For patients with IBD, monitor for recurrent iron deficiency every 3 months for at least a year after correction, and between 6-12 months thereafter 1
Recurrent anemia may indicate persistent disease activity even if there is clinical remission and inflammatory parameters are normal 1
Further investigation is only necessary if hemoglobin and MCV cannot be maintained with supplementation 1

Failure of hemoglobin to rise by 2 g/dL after 3-4 weeks of oral iron therapy may be due to poor compliance, misdiagnosis, continued blood loss, or malabsorption 1
Unabsorbed iron can cause gut irritation, inflammation, and dysbiosis, reducing compliance 2
Recent research suggests that alternate-day dosing (rather than daily) may improve iron absorption and reduce side effects 2
For patients with ongoing blood loss or chronic inflammation, longer treatment courses or maintenance therapy may be necessary 1
Intravenous iron should be considered when oral therapy lacks efficacy, causes intolerable side effects, or in cases of intestinal malabsorption or prolonged inflammation 3