What is the recommended oral iron dosage for adults with iron deficiency anemia based on weight?

Adult Dosage of Iron Based Upon Weight in Iron Deficiency Anemia

The recommended oral iron dosage for adults with iron deficiency anemia is 50-100 mg of elemental iron once daily, which is not weight-based but rather a standard dosing approach for all adults. 1

Initial Treatment Approach

• Oral iron therapy is the first-line treatment for iron deficiency anemia in most adults 1
• The standard initial dose is one tablet per day of ferrous sulfate, fumarate, or gluconate, providing 50-100 mg of elemental iron 1
• Morning administration on an empty stomach is preferred to maximize absorption 1, 2
• Common preparations and their elemental iron content:
  • Ferrous sulfate 200 mg tablet = 65 mg elemental iron 1
  • Ferrous fumarate 322 mg tablet = 106 mg elemental iron 1
  • Ferrous gluconate 300 mg tablet = 37 mg elemental iron 1

Monitoring and Treatment Duration

• Monitor hemoglobin response within the first 4 weeks of starting therapy 1
• An absence of hemoglobin rise of at least 10 g/L after 2 weeks predicts treatment failure (sensitivity 90.1%, specificity 79.3%) 1
• Continue treatment for approximately 3 months after hemoglobin normalization to replenish iron stores 1, 3
• Regular monitoring every 4 weeks until hemoglobin normalizes is recommended 1
• After treatment completion, monitor blood counts periodically (every 6 months initially) to detect recurrent anemia 1

Alternative Dosing Strategies for Intolerance

• If standard dosing causes gastrointestinal side effects, consider:
  • Reduced dose of one tablet every other day 1, 4
  • Alternate-day dosing with 60-120 mg elemental iron (may improve absorption and reduce side effects) 2
  • Ferric maltol 30 mg twice daily for those with persistent intolerance to traditional iron salts 1

Special Considerations

• Parenteral iron should be considered when oral iron is:
  • Contraindicated
  • Ineffective (no appropriate hemoglobin response)
  • Not tolerated due to side effects 1, 4
• Patients with chronic inflammatory conditions (IBD, chronic kidney disease, heart failure) may benefit from parenteral iron over continued oral therapy 1, 5
• Blood transfusion should be reserved only for those with severe symptomatic anemia or circulatory compromise, with a target hemoglobin of 70-90 g/L 1

Common Pitfalls to Avoid

• Switching between different traditional iron salts when side effects occur is not supported by evidence 1
• Modified-release preparations are less suitable for prescribing due to reduced absorption 1
• Dividing daily doses throughout the day may reduce absorption due to hepcidin stimulation 2
• Failure to continue treatment after hemoglobin normalization may result in inadequate replenishment of iron stores 1
• Inadequate monitoring may miss non-responders who need alternative treatment approaches 1