What is the recommended iron supplement dosage for adult men?

Iron Supplement Dosage for Adult Men

For adult men with iron deficiency, the recommended oral iron supplementation dosage is 50-100 mg of elemental iron once daily. 1

Understanding Iron Preparations and Dosing

Different iron preparations contain varying amounts of elemental iron:

Iron Preparation	Typical Tablet Size	Elemental Iron Content
Ferrous sulfate	200 mg	65 mg
Ferrous fumarate	210-322 mg	69-106 mg
Ferrous gluconate	324 mg	38 mg

Optimal Administration

• Take iron supplements in the morning on an empty stomach to maximize absorption 1
• Avoid taking with food, as this can reduce absorption by up to 50%
• Separate iron intake from calcium supplements, antacids, or high-calcium foods by at least 2 hours

Dosing Considerations

Recent evidence suggests that once-daily dosing is more effective than multiple daily doses. This is because:

• Iron doses ≥60 mg stimulate hepcidin production, which reduces subsequent iron absorption for up to 24 hours 2
• Alternate-day dosing may actually improve overall absorption compared to daily dosing for some patients 1

Duration of Treatment

• Continue iron supplementation for 2-3 months after hemoglobin normalizes to replenish iron stores 1
• Monitor hemoglobin response after 2-4 weeks of starting therapy
  • If hemoglobin hasn't increased by at least 10 g/L after 2 weeks, this strongly predicts treatment failure 1

Monitoring Recommendations

After normalization of hemoglobin:

• Check blood count every 3 months for the first year
• Then every 6 months for 2-3 years 1

Common Side Effects and Management

Gastrointestinal side effects are common with oral iron:

• Nausea, constipation, diarrhea, abdominal discomfort
• If side effects occur, consider:
  1. Reducing the dose temporarily
  2. Trying alternate-day dosing
  3. Switching to a different iron preparation (though evidence for this approach is limited) 1

Special Considerations

For men who don't respond to oral iron or have severe iron deficiency anemia:

• Consider parenteral (IV) iron if there's evidence of:
  • Malabsorption
  • Ongoing blood loss
  • Inflammatory bowel disease
  • Other conditions affecting absorption 1

Common Pitfalls to Avoid

• Using modified-release iron preparations, which have reduced absorption
• Prescribing multiple daily doses when once-daily dosing is more effective
• Failing to continue therapy long enough to replenish iron stores
• Not investigating the underlying cause of iron deficiency in adult men

Remember that iron deficiency in adult men often indicates underlying pathology and warrants investigation for potential gastrointestinal bleeding or malabsorption.