What is the recommended dose of ferrous sulphate (iron supplement) for mild iron deficiency anemia?

Recommended Dosage of Ferrous Sulphate for Mild Iron Deficiency Anemia

For mild iron deficiency anemia, the recommended dose of ferrous sulphate is 60-100 mg of elemental iron once daily, which is equivalent to approximately 200-300 mg of ferrous sulphate per day. 1

Dosing Recommendations Based on Patient Type

General Population with Mild Iron Deficiency Anemia

• Ferrous sulphate 200 mg (containing approximately 65 mg elemental iron) once daily is effective for most adults with mild iron deficiency anemia 1, 2
• Morning administration is preferable as it maximizes absorption 3
• Single daily dosing is as effective as divided doses and may improve compliance 4, 5
• Alternate-day dosing may improve absorption and reduce side effects compared to consecutive daily dosing 3, 4

Special Populations

• Pregnant women: 60-120 mg elemental iron daily (equivalent to 200-300 mg ferrous sulphate) 1
• Women with heavy menstrual bleeding: May require higher doses of 50-100 mg elemental iron daily 1
• Patients with IBD: No more than 100 mg elemental iron per day is recommended 1

Administration Guidelines

Optimizing Absorption

• Take iron supplements in the morning rather than afternoon or evening 3
• Take on an empty stomach if tolerated (1 hour before or 2 hours after meals) 1
• Take with vitamin C (ascorbic acid) or citrus juice to enhance absorption 1
• Avoid taking with calcium supplements, dairy products, tea, coffee, or antacids which can reduce absorption 1
• Separate iron and calcium supplements by 1-2 hours 1

Duration of Treatment

• Continue treatment for 3 months after hemoglobin normalizes to replenish iron stores 1
• For women with confirmed iron deficiency anemia, continue iron treatment for 2-3 months after normalization of hemoglobin 1

Monitoring Response

• Expect hemoglobin to rise by approximately 1 g/dL after 4 weeks of therapy 1
• If no response after 4 weeks despite compliance, further evaluation is needed 1
• Monitor hemoglobin and red cell indices at 3-month intervals for the first year after correction, then annually 1

Common Side Effects and Management

• Gastrointestinal side effects include nausea, constipation, abdominal discomfort, and dark stools 1
• Side effects are dose-dependent; lower doses may be better tolerated 1
• If side effects occur:
  • Consider taking with food (though this may reduce absorption by 40-50%) 1
  • Try alternate-day dosing 3, 4
  • Consider switching to a different iron formulation such as ferrous gluconate or ferrous fumarate 1

When to Consider Alternative Approaches

• Consider intravenous iron if:
  • Oral iron is not tolerated 1
  • Patient has malabsorption issues 1
  • There is no response to oral iron therapy after 4 weeks 1
  • Patient has severe anemia (Hb <10 g/dL) 1

Important Considerations

• Each tablet of ferrous sulphate (324 mg) typically contains 65 mg of elemental iron 2
• No more than 100 mg of elemental iron per day is recommended for most patients to minimize side effects 1
• Recent research suggests that lower doses (60-100 mg elemental iron) may be as effective as higher doses while causing fewer side effects 6, 3
• Alternate-day dosing may improve iron absorption by allowing hepcidin levels to return to baseline between doses 3, 4