Does an adult patient, possibly a female of childbearing age, with microcytic anemia, low hemoglobin (7.6), low hematocrit (29.5), low mean corpuscular volume (66), and elevated red blood cell distribution width (20.9), need prescription oral iron supplements?

Does This Patient Need Prescription Oral Iron Supplementation?

Yes, this patient absolutely requires iron supplementation immediately—the laboratory findings demonstrate severe microcytic anemia with markedly elevated RDW (20.9%), which is pathognomonic for iron deficiency anemia requiring urgent treatment. 1

Diagnostic Confirmation

The laboratory values definitively establish iron deficiency anemia:

• Hemoglobin 7.6 g/dL represents severe anemia requiring prompt intervention 1
• MCV 66 fL with RDW 20.9% is the classic pattern distinguishing iron deficiency from thalassemia trait (which would show normal RDW ≤14.0%) 1, 2
• The combination of low MCV with high RDW (>14.0%) strongly indicates iron deficiency anemia rather than genetic causes 1, 2

While serum ferritin would be the definitive confirmatory test (with <15 μg/L indicating absent iron stores and <45 μg/L optimal for diagnosis), the clinical picture is sufficiently clear to initiate treatment 1

Treatment Protocol

First-line treatment is oral iron supplementation with ferrous sulfate 200 mg three times daily for at least three months after correction of anemia to replenish iron stores. 1

Alternative formulations if ferrous sulfate is not tolerated:

• Ferrous gluconate 1
• Ferrous fumarate 1
• Adding ascorbic acid can enhance iron absorption 1

Expected response:

• Hemoglobin should rise ≥10 g/L (≥1 g/dL) within 2 weeks if iron deficiency is the cause 1
• Hemoglobin should increase by at least 2 g/dL within 4 weeks 1

Critical Investigation Required

This patient requires urgent investigation for the source of iron loss, as severe iron deficiency in adults always warrants evaluation for occult bleeding: 1

• Adult men with Hb <110 g/L or non-menstruating women with Hb <100 g/L warrant fast-track gastrointestinal referral 1
• If the patient is female of childbearing age, assess for heavy menstrual bleeding (most common cause in premenopausal women) 1
• Gastrointestinal blood loss is found in 60-70% of patients with iron deficiency anemia referred for endoscopy 3
• Consider celiac disease screening, H. pylori infection, or autoimmune atrophic gastritis if malabsorption suspected 1

Monitoring Plan

• Check hemoglobin concentration and red cell indices at 2 weeks to confirm response 1
• Continue monitoring at three-monthly intervals for one year, then after a further year 1
• Provide additional oral iron if hemoglobin or MCV falls below normal 1
• Monitor serum ferritin and transferrin saturation to assess iron store repletion 1

When to Consider Intravenous Iron

If the patient fails to respond to oral iron therapy within 2-4 weeks, consider: 1

• Non-compliance with oral regimen
• Ongoing blood loss exceeding replacement capacity
• Malabsorption (celiac disease, inflammatory bowel disease, H. pylori, atrophic gastritis)
• True intolerance to oral preparations

In these cases, switch to intravenous iron (iron sucrose or iron gluconate) with expected hemoglobin increase of at least 2 g/dL within 4 weeks 1

Common Pitfalls to Avoid

• Do not assume all microcytic anemia is iron deficiency: While this patient's elevated RDW confirms iron deficiency, thalassemia trait and anemia of chronic disease must be differentiated in other cases to avoid unnecessary iron therapy 1
• Do not overlook combined deficiencies: Iron deficiency can coexist with B12 or folate deficiency 1
• Do not stop iron therapy prematurely: Continue for at least 3 months after hemoglobin correction to replenish iron stores 1
• Ferritin can be falsely elevated by inflammation: In the presence of inflammation, ferritin up to 100 μg/L may still be consistent with iron deficiency 1

Rare Genetic Considerations (Unlikely in This Case)

Given the patient's age and presentation, genetic disorders of iron metabolism (IRIDA, SLC11A2 defects) are extremely unlikely but should be considered only if: 4

• Failure to respond to both oral and intravenous iron
• Family history of refractory anemia
• Low-to-normal ferritin with remarkably low transferrin saturation
• Extreme microcytosis (MCV <60 fL) from early childhood