What is the best treatment approach for a 30-year-old female with severe iron deficiency anemia?

Treatment of Severe Iron Deficiency Anemia in a 30-Year-Old Female

Start oral ferrous sulfate 200 mg once daily on an empty stomach, add vitamin C 500 mg with each dose to enhance absorption, and continue treatment for 3 months after hemoglobin normalizes to replenish iron stores. 1, 2

Immediate Treatment Strategy

First-Line Oral Iron Therapy

• Ferrous sulfate 200 mg once daily is the preferred formulation due to its effectiveness and low cost 1, 2
• Take on an empty stomach for optimal absorption, though taking with food is acceptable if gastrointestinal side effects occur 2
• Add vitamin C (ascorbic acid) 500 mg with each iron dose to enhance absorption—this is particularly critical given severe iron deficiency 2
• Once-daily dosing is superior to multiple daily doses because it improves tolerance while maintaining effectiveness 1, 3
• If side effects occur, switch to alternate-day dosing (200 mg every other day), which actually increases fractional iron absorption 1, 3

Alternative Formulations if Needed

• Ferrous gluconate or ferrous fumarate are equally effective if ferrous sulfate is not tolerated 1, 2
• Ferric maltol (30 mg twice daily) is an option for patients who cannot tolerate traditional iron salts, though it is more expensive and has slower iron loading 1

Expected Response and Monitoring

• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment 1, 2
• If no response occurs within 4 weeks despite compliance and absence of acute illness, reassess for malabsorption, ongoing blood loss, or non-adherence 1
• Continue oral iron for 3 months after hemoglobin normalizes to ensure adequate repletion of marrow iron stores 1, 2
• Monitor hemoglobin and red cell indices at 3-month intervals for the first year after correction, then again after another year 1, 2

When to Switch to Intravenous Iron

Consider IV iron if the patient meets any of these criteria:

• Intolerance to at least two different oral iron preparations 1, 2
• Inadequate response to oral iron after 4 weeks despite compliance 1, 2
• Conditions affecting iron absorption (celiac disease, inflammatory bowel disease with active inflammation, post-bariatric surgery) 1, 2
• Hemoglobin <10 g/dL with ongoing symptoms requiring rapid correction 2

Preferred IV Iron Formulations

• Use formulations that can replace iron deficits with 1-2 infusions rather than multiple infusions 2
• Ferric carboxymaltose (500-1000 mg single doses) can be delivered within 15 minutes 2
• Avoid iron dextran preparations due to higher risk of anaphylaxis 2

Investigation for Underlying Cause

In a 30-year-old premenopausal woman, the diagnostic approach should be:

Initial Assessment

• Assess menstrual blood loss first, as menorrhagia is responsible for iron deficiency in 5-10% of menstruating women 2
• Consider pictorial blood loss assessment charts (80% sensitivity and specificity for detecting menorrhagia) 2
• Screen for celiac disease with antiendomysial antibody and IgA measurement, as this is a common cause of malabsorption in younger patients 2

When to Pursue Gastrointestinal Investigation

• Gastrointestinal endoscopy is NOT routinely indicated in premenopausal women <40 years without alarm symptoms 2, 4
• Perform upper endoscopy only if there are upper GI symptoms (dyspepsia, reflux, dysphagia) 2
• Perform colonoscopy only if there are specific indications: rectal bleeding, family history of colon cancer, alarm symptoms (weight loss, abdominal pain), or elevated inflammatory markers 2

Common Pitfalls to Avoid

• Do not prescribe multiple daily doses—this increases side effects without improving efficacy due to hepcidin elevation 1, 2, 3
• Do not stop iron therapy when hemoglobin normalizes—continue for 3 months to replenish stores 1, 2
• Do not overlook vitamin C supplementation when oral iron response is suboptimal 2
• Do not continue oral iron indefinitely without response—reassess after 4 weeks and switch to IV iron if hemoglobin fails to rise 2
• Do not fail to identify and treat the underlying cause while supplementing iron 2

Failure to Respond

If anemia does not resolve within 6 months despite appropriate iron therapy:

• Reassess for ongoing blood loss (including occult menorrhagia) 1, 2
• Evaluate for malabsorption syndromes (celiac disease, atrophic gastritis, H. pylori infection) 2, 4
• Verify patient adherence to therapy 2
• Consider hematology consultation for complex cases 2
• Perform bidirectional endoscopy if not previously done and no clear cause identified 4