What is the recommended dose of iron supplement for treating iron deficiency anemia?

Iron Supplementation Dosage for Iron Deficiency Anemia

For iron deficiency anemia, the recommended dosage is 60-120 mg of elemental iron daily for adults, with specific dosing regimens based on patient population and severity of anemia. 1

Recommended Dosages by Population

Adults and Adolescents

• Nonpregnant women and adolescent girls: 60-120 mg of elemental iron daily 2
• School-age children: One 60-mg iron tablet daily 2
• Adolescent boys: Two 60-mg iron tablets daily 2
• Adult men: Similar to nonpregnant women (60-120 mg daily) 1

Pregnant Women

• Preventive supplementation: 30 mg elemental iron daily starting at first prenatal visit 2
• Treatment of anemia during pregnancy: 60-120 mg elemental iron daily 2

Administration Recommendations

Optimal Dosing Schedule

• Morning administration: Take iron in the morning to avoid interference with the circadian increase in plasma hepcidin 1, 3
• Alternate-day dosing: Consider alternate-day dosing rather than daily dosing for better absorption and fewer side effects 1, 3, 4
• Empty stomach: Take iron supplements on an empty stomach for optimal absorption 1, 5
• With vitamin C: If taking with food is necessary due to gastrointestinal side effects, add 500 mg vitamin C to enhance absorption 1

Formulation

• Ferrous sulfate: Preferred formulation, typically containing 65 mg elemental iron per 324 mg tablet 1
• Administration: Do not crush or chew tablets 5

Duration of Treatment

• Standard duration: Continue iron supplementation for 3 months after normalization of hemoglobin to replenish iron stores 1, 6
• Monitoring response: Expect hemoglobin increase of ≥1.0 g/dL within 14 days of starting therapy; if this doesn't occur, consider alternative approaches 7

Managing Side Effects

• Common side effects: Warn patients about constipation (12%), diarrhea (8%), and nausea (11%) 1
• Reducing side effects:
  • Start with lower doses and gradually increase
  • Consider alternate-day dosing if daily dosing is poorly tolerated 1, 4
  • Extended-release formulations may reduce gastrointestinal side effects 6

When to Consider Parenteral Iron

• If oral iron is contraindicated
• If no response to oral iron after 4 weeks
• If oral iron is not tolerated due to side effects 1

Monitoring Recommendations

• Check hemoglobin and red cell indices at 1 month to assess initial response
• Monitor at 3-month intervals for one year after treatment 1
• Target transferrin saturation >20% 1

Common Pitfalls to Avoid

• Discontinuing iron therapy too early before replenishing iron stores
• Not considering IV iron when oral therapy fails
• Relying solely on hemoglobin without checking iron stores
• Failing to investigate underlying cause of iron deficiency 1

Iron supplementation dosing should be tailored based on the severity of anemia, patient population, and response to treatment, with careful monitoring to ensure adequate replenishment of iron stores and resolution of anemia.