What is the recommended dosing for ferrous gluconate (iron supplement) in treating iron deficiency anemia?

Ferrous Gluconate Dosing for Iron Deficiency Anemia

For treating iron deficiency anemia, ferrous gluconate should be administered at a dose of 325 mg (containing 35 mg elemental iron) three times daily to provide a total of approximately 100-105 mg of elemental iron per day. 1

Oral Iron Therapy Recommendations

Standard Dosing

• Ferrous gluconate 325 mg tablets contain 35 mg of elemental iron per tablet 1
• For adults with iron deficiency anemia:
  • Initial dosing: 325 mg three times daily (105 mg elemental iron/day) 1
  • Duration: Continue for 3 months after hemoglobin normalizes to replenish iron stores 1

Alternative Dosing Approaches

• Recent evidence suggests alternate-day dosing may improve absorption:
  • 325 mg once daily or twice daily on alternate days may be more effective than daily divided doses 1, 2, 3
  • Morning administration is preferred over afternoon/evening dosing 2
  • Taking iron without food improves absorption 1

Monitoring Response

• Check hemoglobin every 4 weeks until normalized 1
• After normalization:
  • Monitor every 3 months for one year, then after another year 1
  • Continue iron if hemoglobin or MCV falls below normal 1

Considerations for Special Populations

Chronic Kidney Disease Patients

• For CKD patients not on dialysis: 200 mg elemental iron per day (approximately 6 tablets of ferrous gluconate) 1
• For pediatric patients: 2-3 mg/kg/day of elemental iron 1

Patients with Intolerance

If GI side effects occur with standard dosing:

1. Try alternate-day dosing (325 mg once or twice daily on alternate days) 1, 2
2. Consider taking with ascorbic acid to enhance absorption 1
3. Switch to IV iron if intolerant to at least two oral preparations 1

Comparison with Other Oral Iron Preparations

Iron Preparation	Tablet Size (mg)	Elemental Iron (mg)	Cost Comparison
Ferrous gluconate	325	35	Higher cost
Ferrous sulfate	325	65	Lower cost
Ferrous fumarate	325	108	Lowest cost

Common Pitfalls and Caveats

• Inadequate duration of therapy is common - continue for 3 months after hemoglobin normalizes 1
• Taking iron with food reduces absorption by up to 50% 1
• Failure to respond to oral iron may indicate:
  • Poor compliance
  • Continued blood loss
  • Malabsorption
  • Incorrect diagnosis 1
• In patients with inflammatory conditions, oral iron absorption may be impaired due to hepcidin upregulation 1, 2
• Dividing doses throughout the day may actually reduce absorption by increasing hepcidin levels 2, 3

For patients who fail to respond to oral iron therapy, have severe anemia, or have conditions limiting oral iron absorption (such as inflammatory bowel disease, chronic kidney disease, or heart failure), intravenous iron should be considered 1, 4.