What is the recommended iron supplement dosage for a 22-year-old female?

Recommended Iron Supplementation for a 22-Year-Old Female

For a 22-year-old woman without diagnosed iron deficiency anemia, the recommended dietary iron intake is 18 mg/day, which should ideally come from food sources rather than supplements. 1

Preventive Supplementation (No Anemia)

• Most young women do not require iron supplements unless they have specific risk factors such as heavy menstrual bleeding, low dietary iron intake, or previous iron deficiency anemia 1
• The standard recommended daily allowance for women aged 19-50 years is 18 mg/day of dietary iron 1
• For female athletes or highly active women, higher intake of at least 22 mg/day may be beneficial due to increased losses 1

When Supplementation is Indicated

If this woman has confirmed iron deficiency or iron deficiency anemia, treatment recommendations change significantly:

First-Line Treatment: Ferrous Sulfate

• Take ferrous sulfate 200 mg (containing 65 mg elemental iron) once daily in the morning on an empty stomach 2, 3, 4
• This is the most cost-effective formulation and considered the gold standard 2, 5
• The optimal dose is 50-100 mg of elemental iron once daily 2, 3

Optimal Dosing Strategy

• Single morning dose on an empty stomach maximizes absorption 2, 3
• Take with 250-500 mg vitamin C (or a glass of orange juice) to enhance absorption 2, 3, 6
• Avoid multiple daily doses, as iron doses ≥60 mg stimulate hepcidin elevation that persists for 24 hours and blocks subsequent absorption 2, 7, 8
• If daily dosing causes intolerable side effects, alternate-day dosing with 100-120 mg elemental iron significantly increases fractional absorption and reduces gastrointestinal side effects 2, 7, 8

What to Avoid

• Do not take iron with tea, coffee, or calcium-containing foods/supplements, as these significantly inhibit absorption 2, 3
• Avoid modified-release preparations, which are considered "less suitable for prescribing" 2, 3
• Do not rely on multivitamins, as they typically contain insufficient elemental iron (≤14 mg) for treating deficiency 2, 3

Alternative Formulations (If Ferrous Sulfate Not Tolerated)

• Ferrous fumarate 210-322 mg tablets (providing 69-106 mg elemental iron) 3
• Ferrous gluconate 324 mg tablets (providing 38 mg elemental iron) 9
• Ferric maltol 30 mg twice daily for patients with previous intolerance, though considerably more expensive 2, 5

Monitoring Response

• Hemoglobin should increase by at least 10 g/L (1 g/dL) within 2 weeks if treatment is effective 2, 3, 5
• Failure to achieve this increase strongly predicts treatment failure (sensitivity 90.1%, specificity 79.3%) 2, 3
• Continue treatment for approximately 3 months after hemoglobin normalizes to ensure adequate repletion of iron stores 1, 2, 5

Special Considerations for Young Women

• Screen for anemia every 5-10 years during routine health examinations starting in adolescence 1
• Annual screening is recommended for women with risk factors including extensive menstrual blood loss, low iron intake, or previous iron deficiency 1
• If anemia does not respond to iron treatment after 4 weeks despite compliance, further evaluation is needed including MCV, RDW, and serum ferritin 1
• In women of African, Mediterranean, or Southeast Asian ancestry, mild anemia unresponsive to iron therapy may indicate thalassemia minor or sickle cell trait 1

When to Consider Intravenous Iron

• Intravenous iron should be considered when oral iron is not tolerated despite modifications, ferritin levels fail to improve with oral trial, or conditions impair oral absorption 2, 5
• IV iron produces clinically meaningful hemoglobin response within one week 2, 5