What is the appropriate management for a 39-year-old female with iron deficiency anemia, as indicated by low ferritin, iron levels, hemoglobin, and hematocrit, along with other relevant laboratory results?

Management of Iron Deficiency Anemia in a 39-Year-Old Female

This patient requires immediate investigation for gastrointestinal blood loss with bidirectional endoscopy and celiac disease screening, alongside initiation of oral iron supplementation. 1

Diagnostic Confirmation

Your patient has clear-cut iron deficiency anemia based on:

• Hemoglobin 8.2 g/dL (severely below the WHO threshold of <12 g/dL for non-pregnant women) 1
• Ferritin 9 ng/mL (well below the 15 ng/mL threshold that is 99% specific for iron deficiency) 1
• Transferrin saturation 12% (below the 20% threshold indicating iron deficiency) 1, 2
• Low iron (39) with elevated TIBC (315) confirming depleted iron stores 1

The elevated B12 and folate exclude other nutritional causes of anemia. 1

Urgent Investigation Required

All premenopausal women with confirmed IDA require screening for celiac disease, and this patient's severe anemia (Hb <10 g/dL) warrants urgent gastrointestinal investigation despite her reproductive age. 1

Investigation Algorithm:

1. Screen for celiac disease with tissue transglutaminase (tTG) antibody testing immediately 1

2. Test for Helicobacter pylori non-invasively (urea breath test or stool antigen) 1

3. Perform bidirectional endoscopy (both upper and lower GI) because: 1

   • The hemoglobin of 8.2 g/dL represents severe anemia
   • The British Society of Gastroenterology 2021 guidelines recommend investigation at any level of anemia with iron deficiency when serious pathology is more likely 1
   • Dual pathology (upper and lower GI sources) occurs in 1-10% of patients 1
   • Even premenopausal women with this degree of anemia require investigation beyond menstrual causes 1

4. Reserve small bowel evaluation (video capsule endoscopy) only if bidirectional endoscopy is unrevealing and anemia persists despite iron therapy 1

Iron Replacement Therapy

Initiate oral iron supplementation immediately—do not wait for investigation results. 1, 2

Oral Iron Regimen:

• Ferrous sulfate 325 mg daily (containing 65 mg elemental iron) 3, 2
• Alternative dosing: 325 mg on alternate days if gastrointestinal side effects occur (this maintains efficacy while improving tolerance) 2
• Take with vitamin C to enhance absorption; avoid tea, coffee, and calcium supplements around dosing times 1

Expected Response:

• Hemoglobin should rise ≥10 g/L within 2 weeks if iron deficiency is the sole cause 1
• Recheck complete blood count, ferritin, and iron studies at 8-10 weeks 4
• Continue iron supplementation until ferritin reaches >100 ng/mL to replete stores 1, 4

When to Consider Intravenous Iron

Switch to intravenous iron if: 2

• Oral iron is not tolerated despite alternate-day dosing
• Hemoglobin fails to rise appropriately after 4-6 weeks
• Celiac disease or malabsorption is confirmed
• Ongoing blood loss is identified
• Patient requires rapid correction due to symptoms

Critical Pitfalls to Avoid

Do not attribute this severe anemia solely to menstruation without investigation. While menstrual blood loss is common in premenopausal women, a hemoglobin of 8.2 g/dL with ferritin of 9 ng/mL suggests blood loss exceeding normal menstrual losses or an additional pathology. 1, 2

Do not perform fecal occult blood testing—it has no role in IDA investigation and should not delay endoscopy. 1

Do not give blood transfusion unless the patient has cardiovascular instability or symptoms of hemodynamic compromise. 1

Do not stop investigation if celiac disease is found in a patient over age 50 or with marked anemia, as dual pathology may exist. 1

Monitoring Plan

• Recheck CBC, ferritin, and transferrin saturation at 8-10 weeks 4
• If anemia resolves but ferritin remains <30 ng/mL, continue intermittent oral iron supplementation 4
• Monitor every 6-12 months long-term if ferritin repeatedly drops below 30 ng/mL 4