What oral iron supplement is recommended as first‑line therapy for an otherwise healthy adolescent female with iron‑deficiency anemia in the Philippines?

Best Iron Supplements for Iron-Deficiency Anemia in Adolescent Females

Prescribe ferrous sulfate 200 mg (65 mg elemental iron) once daily, taken on an empty stomach in the morning, as first-line therapy for an otherwise healthy adolescent female with iron-deficiency anemia. 1

First-Line Oral Iron Formulation

Ferrous sulfate is the gold-standard oral iron supplement because it provides the highest elemental iron content (65 mg per 200 mg tablet) at the lowest cost, with no proven superiority of any alternative formulation in terms of efficacy or tolerability. 1, 2, 3

Dosing Strategy for Adolescent Females

• Prescribe 60-120 mg elemental iron once daily for adolescent girls with confirmed iron-deficiency anemia. 4, 1
• Once-daily dosing is superior to multiple daily doses because iron intake triggers hepcidin elevation that persists for 24-48 hours, blocking subsequent iron absorption and increasing gastrointestinal side effects without improving hemoglobin response. 1, 2
• Take the dose on an empty stomach in the morning to maximize absorption, though it may be taken with food if gastrointestinal intolerance occurs. 1, 2

Enhancing Absorption

• Add vitamin C 250-500 mg with each iron dose to markedly enhance absorption, especially critical when transferrin saturation is low. 1, 5, 2
• Avoid tea, coffee, or calcium-containing products within 1 hour of taking iron, as these inhibit absorption. 1, 2

Alternative Oral Formulations (If Ferrous Sulfate Not Tolerated)

If ferrous sulfate causes intolerable gastrointestinal side effects after adequate trial:

• Ferrous fumarate (69-106 mg elemental iron per tablet) is equally effective. 1, 2
• Ferrous gluconate (37-38 mg elemental iron per tablet) is equally effective. 1, 2
• All ferrous salts have similar efficacy and tolerability—no single formulation has proven advantages over others. 1, 2

Alternate-Day Dosing Option

• If daily dosing causes intolerable side effects, switch to alternate-day dosing with 100-200 mg elemental iron, which increases fractional absorption and reduces gastrointestinal symptoms while maintaining efficacy. 1, 2

Expected Response and Treatment Duration

• Check hemoglobin at 4 weeks—expect a rise of ≥1 g/dL (≥10 g/L) if treatment is effective. 4, 1, 2
• Continue oral iron for 2-3 months after hemoglobin normalizes to fully replenish iron stores, resulting in a total treatment duration of approximately 6-7 months. 4, 1, 2
• Monitor hemoglobin every 3 months during the first year, then again after another year. 1, 2

When to Switch to Intravenous Iron

Switch to IV iron if any of the following occur:

• Intolerance to at least two different oral iron preparations (e.g., ferrous sulfate and ferrous fumarate). 1, 5
• Ferritin fails to improve after 4 weeks of compliant oral therapy. 1, 5
• Hemoglobin fails to rise by ≥1 g/dL after 4 weeks despite adherence. 4, 1
• Active inflammatory bowel disease with hemoglobin <10 g/dL (inflammation-induced hepcidin blocks oral absorption). 1, 5
• Ongoing gastrointestinal blood loss exceeding oral replacement capacity. 1, 5

Preferred IV Iron Formulations

• Ferric carboxymaltose (750-1000 mg per 15-minute infusion; two doses ≥7 days apart) or ferric derisomaltose (1000 mg single infusion) are preferred because they replenish iron deficits in 1-2 sessions. 1, 5

Available Formulations in the Philippines

While specific Philippine brand names vary, look for:

• Ferrous sulfate 200 mg tablets (generic or branded—e.g., Iberet-Folic contains ferrous sulfate)
• Ferrous fumarate preparations (e.g., Ferodan, Hemobion)
• Ferrous gluconate preparations (various brands available)

All ferrous salts are equally effective—choose based on availability and cost. 1, 2

Critical Pitfalls to Avoid

• Do not prescribe multiple daily doses—this increases side effects without improving efficacy due to hepcidin-mediated absorption blockade. 1, 2
• Do not stop iron therapy when hemoglobin normalizes—continue for 2-3 additional months to replenish stores. 4, 1
• Do not persist with oral iron beyond 4 weeks without hemoglobin response—reassess for malabsorption, ongoing blood loss, or need for IV iron. 1, 5
• Do not overlook vitamin C supplementation when oral iron response is suboptimal. 1, 5
• Do not use modified-release preparations—they release iron beyond the duodenum (primary absorption site) and are less suitable for prescribing. 2
• Do not rely on multivitamin preparations alone—they typically contain insufficient elemental iron (≤14 mg) for treating iron-deficiency anemia. 2

Special Considerations for Adolescent Females

• Assess menstrual blood loss first, as menorrhagia accounts for iron deficiency in 5-10% of menstruating women. 4, 1
• Screen for celiac disease with tissue transglutaminase IgA antibodies if malabsorption is suspected or if oral iron fails. 1, 5
• Evaluate dietary iron intake and provide counseling on iron-rich foods and foods that enhance iron absorption. 4, 1