What is the recommended dose of elemental iron (Fe) for a teenager with iron deficiency or insufficiency?

Recommended Iron Dose for Teenagers

For adolescents with iron deficiency or iron deficiency anemia, prescribe 60-120 mg of elemental iron once daily, taken in the morning on an empty stomach. 1, 2

Specific Dosing by Age and Sex

Adolescent Girls (12-18 years)

• Treatment dose: 60-120 mg elemental iron daily for confirmed iron deficiency anemia 1
• One standard ferrous sulfate 200 mg tablet (containing 65 mg elemental iron) once daily is typically sufficient 2
• For severe or symptomatic anemia, use the higher end of the dosing range (100-120 mg daily) 2

Adolescent Boys (12-18 years)

• Treatment dose: Two 60 mg iron tablets daily (120 mg total elemental iron) 1
• This higher dose reflects the increased iron needs during rapid growth in male adolescents 1

Athletes and Highly Active Teenagers

• Female athletes should consume at least 22 mg/day of dietary iron (higher than the standard 15-18 mg RDA) 1
• If supplementation is needed for confirmed deficiency, use the standard treatment doses above (60-120 mg elemental iron) 1

Optimal Administration Strategy

Timing and Frequency

• Give as a single morning dose on an empty stomach to maximize absorption 2, 3
• Avoid multiple daily doses—iron doses ≥60 mg stimulate hepcidin elevation that blocks subsequent iron absorption for 24 hours 3, 4
• If daily dosing causes intolerable gastrointestinal side effects, switch to alternate-day dosing with 100-200 mg elemental iron, which actually increases fractional absorption 3, 4

Enhancing Absorption

• Take with 250-500 mg vitamin C to enhance absorption 3
• Avoid taking with food, tea, coffee, or calcium-containing products, which significantly reduce absorption 3

Duration of Treatment

• Continue treatment for 2-3 months after hemoglobin normalizes to adequately replenish iron stores 1, 2
• Monitor hemoglobin at 4 weeks—expect an increase of ≥1 g/dL if treatment is effective 1, 2
• After successful treatment, recheck hemoglobin approximately 6 months later to detect recurrence 1

Iron Formulation Options

Ferrous sulfate is the most cost-effective first-line option: 2, 3

• Ferrous sulfate 200 mg tablets = 65 mg elemental iron
• Ferrous fumarate 200 mg tablets = 69 mg elemental iron
• Ferrous gluconate 300 mg tablets = 37 mg elemental iron

All ferrous salts have similar efficacy and tolerability—no single formulation has proven advantages 3

When to Consider Parenteral Iron

Switch to intravenous iron if: 2, 5

• Oral iron fails after 4 weeks despite documented compliance
• Severe symptomatic anemia requiring rapid correction
• Chronic inflammatory conditions (inflammatory bowel disease) that impair oral absorption 5
• Intolerable gastrointestinal side effects despite dose modifications 2

Critical Pitfalls to Avoid

• Do not prescribe modified-release or enteric-coated preparations—they are less suitable and more expensive without proven benefit 2, 3
• Do not rely on multivitamins which contain insufficient elemental iron (typically ≤14 mg) for treating deficiency 3
• Do not continue oral iron indefinitely without monitoring—failure to respond may indicate ongoing blood loss, malabsorption, or concurrent B12/folate deficiency 2
• Do not give iron with food to reduce side effects—this reduces absorption by up to 50%; instead, try alternate-day dosing 2, 3