What level of iron supplement should be started for a patient with iron saturation of 13% and hemoglobin (Hb) level of 11 g/dL, with all other laboratory results within normal limits (WNL)?

Iron Supplementation for Iron Deficiency Anemia

For a patient with iron saturation of 13% and hemoglobin of 11 g/dL with other labs within normal limits, oral ferrous sulfate 325 mg once daily (providing 65 mg of elemental iron) is the recommended initial iron supplementation. 1

Assessment of Iron Status

• The patient's iron saturation of 13% indicates iron deficiency, as transferrin saturation <20% reflects inadequate iron availability for erythropoiesis 2
• With hemoglobin of 11 g/dL, this represents mild anemia according to WHO definitions for non-pregnant women (Hb 11.0-11.9 g/dL) and men (Hb 11.0-12.9 g/dL) 3
• This combination of low transferrin saturation and mild anemia is consistent with iron deficiency anemia 4

Recommended Treatment Approach

Oral Iron Therapy

• Oral iron is the appropriate first-line treatment for this patient with mild anemia (Hb 11 g/dL) and no indication of active inflammatory disease 3
• Ferrous sulfate 325 mg (providing 65 mg of elemental iron) once daily is recommended as the starting dose 1
• Alternative dosing options include:
  • Ferrous sulfate 325 mg every other day, which may improve tolerability while maintaining efficacy 4
  • Ferrous gluconate 324 mg (providing 38 mg of elemental iron) three times daily if ferrous sulfate is not tolerated 5

Dosing Considerations

• The recommended daily dose should not exceed 100 mg of elemental iron per day to minimize gastrointestinal side effects 3
• Taking iron supplements with vitamin C (orange juice) can enhance absorption, while calcium-containing foods and beverages (milk, antacids) can decrease absorption 4
• Oral iron should be taken on an empty stomach if tolerated, but can be taken with food if gastrointestinal side effects occur 4

Monitoring Response

• Hemoglobin levels should begin to rise within 2-4 weeks of starting iron supplementation 2
• Monitor iron parameters (ferritin and transferrin saturation) after 4-8 weeks of therapy 3
• Continue iron supplementation for at least 3 months after normalization of hemoglobin to replenish iron stores 2

When to Consider Intravenous Iron

• Intravenous iron would be indicated if the patient:
  • Fails to respond to oral iron after 4-8 weeks of therapy 3
  • Develops intolerance to oral iron preparations 3
  • Has evidence of malabsorption or ongoing blood loss 3
  • Develops more severe anemia (Hb <10 g/dL) 3

Common Pitfalls and Considerations

• Avoid excessive iron supplementation, as maintaining transferrin saturation >50% or serum ferritin >800 ng/mL can lead to iron overload 3
• If the patient has underlying inflammation, ferritin levels may be falsely elevated and not accurately reflect iron stores 2
• Consider investigating the underlying cause of iron deficiency, particularly in men and non-menstruating women, as gastrointestinal blood loss may indicate serious pathology 4
• Patients with thalassemia intermedia show equal bioavailability of iron from ferritin or ferrous sulfate, suggesting alternative iron formulations can be considered if standard preparations are not tolerated 6