What is the recommended dosage and administration of iron bisglycinate (elemental iron) for patients requiring iron supplementation?

Iron Bisglycinate Supplementation: Dosage and Administration Guidelines

For patients requiring iron supplementation, iron bisglycinate should be administered at a dose of 60-120 mg of elemental iron given as a single morning dose on alternate days to maximize absorption and minimize side effects.

Understanding Iron Bisglycinate

Iron bisglycinate is a chelated form of iron that offers several advantages over traditional iron salts:

• Higher bioavailability
• Better gastrointestinal tolerance
• Lower incidence of side effects

Dosing Recommendations

Adult Dosing:

• Standard dose: 60-120 mg of elemental iron per day
• Optimal administration: Single morning dose on alternate days
• Maximum daily dose: Should not exceed 200 mg of elemental iron

Pediatric Dosing:

• Children: 2-3 mg/kg/day of elemental iron 1
• Maximum dose: 5 mg/day for routine supplementation 1

Administration Guidelines

Timing:

• Preferred timing: Morning administration (single dose)
• Avoid: Afternoon or evening dosing after a morning dose 2
• Schedule: Alternate-day dosing is superior to daily dosing 3

Absorption Enhancement:

• Take on an empty stomach if tolerated
• Avoid taking within 2 hours before or 1 hour after meals 1
• May be taken with vitamin C (ascorbic acid) to enhance absorption 2
• Avoid taking with:
  • Calcium-containing foods or supplements
  • Tea or coffee
  • Antacids
  • Phosphate binders 1

Monitoring Response

1. Initial assessment: Check hemoglobin after 14 days of therapy

   • A ≥1.0 g/dL increase indicates adequate response 4
   • If increase is <1.0 g/dL, consider switching to IV iron 4

2. Follow-up monitoring:

   • Check hemoglobin every 4 weeks until normalization 5
   • Assess iron status (ferritin, transferrin saturation) after 8-10 weeks 5
   • Target ferritin >100 ng/mL and hemoglobin 11-12 g/dL 5

Special Considerations

For Patients with Poor Tolerance:

• Start with lower doses (e.g., 60 mg elemental iron)
• Consider alternate-day dosing to reduce side effects 3
• If GI side effects persist, consider:
  • Taking with small amounts of food (though this may reduce absorption)
  • Switching to IV iron if oral therapy fails 5

For Patients with Ongoing Blood Loss:

• Higher doses may be required
• Consider IV iron therapy if losses exceed oral replacement capacity 5

For Patients with Chronic Kidney Disease:

• Oral iron may be less effective due to hepcidin-mediated iron blockade
• IV iron may be preferred in advanced CKD 1

Common Pitfalls to Avoid

1. Overdosing: High doses don't improve absorption and increase side effects 2, 6
2. Split dosing: Dividing doses throughout the day increases hepcidin and reduces absorption from subsequent doses 3
3. Evening dosing: Circadian increases in hepcidin make evening doses less effective 2
4. Continuing ineffective oral therapy: If no significant hemoglobin response after 14 days, consider IV iron 4
5. Inadequate duration: Continue supplementation for 2-3 months after hemoglobin normalization to replenish iron stores 5

Evidence-Based Rationale

Recent research demonstrates that the traditional approach of high-dose, multiple daily iron supplementation is suboptimal. The body regulates iron absorption through hepcidin, which increases after iron ingestion and limits absorption of subsequent doses 3. Studies show that alternate-day dosing results in significantly higher fractional iron absorption (21.8% vs 16.3%) and total iron absorption (175.3 mg vs 131.0 mg) compared to consecutive-day dosing 3.