Best Iron Supplement for Teenagers with Iron Deficiency Anemia
For teenagers with iron deficiency anemia, ferrous sulfate is the superior choice, dosed at 60-120 mg of elemental iron daily, taken as a single morning dose on alternate days to maximize absorption and minimize side effects. 1, 2, 3, 4
Specific Iron Formulation
Ferrous sulfate is the first-line iron supplement because it provides the most elemental iron per dose, is the most cost-effective, and has superior efficacy compared to other formulations. 5, 1, 6, 3
- Each 324 mg ferrous sulfate tablet contains 65 mg of elemental iron. 7
- In a head-to-head randomized trial, ferrous sulfate increased hemoglobin by 1.0 g/dL more than iron polysaccharide complex over 12 weeks (P < .001), and achieved complete resolution of anemia in 29% vs 6% of patients. 3
- Alternative ferrous salts (ferrous gluconate or ferrous fumarate) can be used if ferrous sulfate is not tolerated, though they contain less elemental iron per tablet. 1, 8
Optimal Dosing Strategy
The recommended dose is 60-120 mg of elemental iron daily for adolescent females. 5, 1, 2
- For adolescent boys, two 60-mg iron tablets daily (120 mg total) is recommended. 5
- Recent evidence shows that alternate-day dosing is superior to daily dosing because iron doses ≥60 mg stimulate hepcidin elevation that persists 24 hours and blocks absorption of subsequent doses. 4
- Give the dose as a single morning administration rather than divided doses, as the circadian increase in hepcidin is augmented by morning iron, making afternoon/evening doses less effective. 4
Administration Guidelines
Iron should be taken between meals or on an empty stomach to maximize absorption, as food reduces iron absorption by up to 50%. 5, 1
- If gastrointestinal side effects occur (nausea, constipation, abdominal pain), the dose can be taken with meals, though this reduces absorption. 1
- Adding vitamin C (ascorbic acid) enhances iron absorption and should be recommended. 1, 4
- Avoid taking iron within 2 hours of aluminum-based phosphate binders, which reduce absorption. 5
Treatment Duration and Monitoring
Recheck hemoglobin after 4 weeks of treatment. 5, 1, 2
- An increase of ≥1 g/dL hemoglobin (or ≥3% hematocrit) confirms the diagnosis of iron deficiency anemia and indicates treatment response. 5, 1, 2
- Continue iron therapy for an additional 2-3 months after hemoglobin normalizes to replenish iron stores. 5, 1, 2
- Reassess hemoglobin approximately 6 months after completing treatment. 5, 1, 2
When Oral Iron Fails
If no response occurs after 4 weeks despite documented compliance, further evaluate with MCV, RDW, and serum ferritin to confirm iron deficiency versus other causes of anemia. 5, 1, 2
- Consider intravenous iron therapy only when there is intolerance to at least two oral iron preparations, documented non-compliance, or conditions with compromised absorption (such as inflammatory bowel disease). 1
- Among IV iron formulations, iron sucrose is most commonly used in adolescents and has the best safety profile, though no IV iron product is currently approved for children in Europe. 5, 6
Critical Pitfalls to Avoid
Do not prescribe iron polysaccharide complex as it is more expensive, no better tolerated, and significantly less effective than ferrous sulfate. 5, 3
- Despite marketing claims, iron polysaccharide complex resulted in more diarrhea (58% vs 35%) compared to ferrous sulfate in a randomized trial. 3
- Do not use divided daily dosing (twice or three times daily), as this reduces total iron absorption due to hepcidin elevation from the first dose. 4
- Parenteral iron should not be first-line therapy as it is painful, expensive, carries risk of anaphylaxis, and provides no faster hemoglobin rise than oral iron in most cases. 1
Dietary Counseling
Counsel teenagers to consume iron-rich foods, particularly heme iron from meat sources, which has superior bioavailability compared to plant-based non-heme iron. 1