What is the recommended treatment for an 8% iron deficiency?

Treatment of 8% Iron Deficiency

Immediate Treatment Recommendation

Start oral ferrous sulfate 200 mg once daily in the morning on an empty stomach, which is the preferred first-line treatment for iron deficiency. 1

Understanding the Clinical Context

The term "8% iron deficiency" most likely refers to transferrin saturation of 8%, which is severely low (normal range 20-50%) and indicates significant iron depletion requiring treatment. 2 This level of deficiency warrants immediate supplementation regardless of whether anemia is present, as iron deficiency causes symptoms even without anemia. 3

Optimal Oral Iron Regimen

Dosing Strategy

• Ferrous sulfate 200 mg once daily is the recommended formulation due to its effectiveness and low cost. 1
• Give the dose in the morning on an empty stomach to maximize absorption, as the circadian increase in hepcidin is augmented by morning dosing. 4
• Consider alternate-day dosing (120 mg every other day) if gastrointestinal side effects occur, as this improves tolerability while maintaining or even increasing total iron absorption. 4
• Add vitamin C (ascorbic acid) 500 mg with each iron dose to enhance absorption, particularly important with severely low iron saturation. 1, 4

Alternative Formulations

• If ferrous sulfate is not tolerated, switch to ferrous gluconate or ferrous fumarate, which are equally effective. 1
• Do not use multiple daily doses, as this increases side effects without improving efficacy. 1

Duration and Monitoring

Treatment Duration

• Continue oral iron therapy for 3 months after anemia correction (or after ferritin normalizes if no anemia) to fully replenish iron stores. 1
• Do not stop when hemoglobin normalizes, as stores require additional time to replenish. 1

Expected Response

• Hemoglobin should rise by approximately 2 g/dL after 3-4 weeks of treatment. 1
• If no response occurs within 4 weeks, assess for non-adherence, malabsorption, or ongoing blood loss. 1

Monitoring Schedule

• Check hemoglobin and red cell indices at 3-4 weeks to confirm response. 1
• Monitor every 3 months for the first year, then again after another year. 1
• Measure ferritin to confirm store repletion after completing the 3-month post-correction treatment course. 2

When to Switch to Intravenous Iron

Absolute Indications

• Intolerance to at least two different oral iron preparations despite trying alternate-day dosing. 1
• Inflammatory bowel disease with active inflammation, especially if hemoglobin is less than 10 g/dL. 2, 1
• Post-bariatric surgery patients due to disrupted duodenal iron absorption. 1
• Celiac disease with inadequate response to oral iron despite gluten-free diet adherence. 1
• Ongoing gastrointestinal blood loss exceeding oral replacement capacity. 1

IV Iron Formulations

• Prefer IV iron formulations that can replace iron deficits with 1-2 infusions, such as ferric carboxymaltose. 2, 1
• Iron dextran carries a higher risk of anaphylaxis and should be avoided. 1
• In critically ill patients with inflammation, a 1 g dose of ferric carboxymaltose has been associated with reduced hospital stay and 90-day mortality. 2

Identifying and Treating the Underlying Cause

Essential Investigations

• In premenopausal women, assess menstrual blood loss patterns and consider gynecologic evaluation if heavy menstrual bleeding is present. 3
• In men and postmenopausal women, perform upper endoscopy and colonoscopy to evaluate for gastrointestinal blood loss. 1
• Screen for celiac disease with antiendomysial antibody and IgA measurement, as this affects iron absorption. 1
• Evaluate for inflammatory conditions including inflammatory bowel disease, chronic kidney disease, and heart failure. 3

Addressing Absorption Issues

• In celiac disease, ensure strict adherence to gluten-free diet to improve iron absorption. 1
• In inflammatory bowel disease, treat active inflammation first to enhance iron absorption and reduce iron depletion. 2, 1
• Avoid taking iron with calcium supplements, tea, coffee, or high-fiber foods that inhibit absorption. 2

Common Pitfalls to Avoid

• Do not continue oral iron indefinitely without response - reassess after 4 weeks and switch to IV iron if hemoglobin fails to rise. 1
• Do not use multiple daily doses - once-daily or alternate-day dosing is better tolerated with similar efficacy. 1, 4
• Do not stop iron therapy when hemoglobin normalizes - continue for 3 months to replenish stores. 1
• Do not overlook vitamin C supplementation when oral iron response is suboptimal. 1, 4
• Do not fail to identify and treat the underlying cause while supplementing. 1
• Do not give iron doses in the afternoon or evening after a morning dose, as this reduces absorption due to hepcidin elevation. 4

Failure to Respond

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

• Reassess for ongoing blood loss through repeat endoscopic evaluation. 1
• Evaluate for malabsorption syndromes including celiac disease, atrophic gastritis, and Helicobacter pylori infection. 1
• Verify patient adherence to therapy and proper timing of doses. 1
• Consider hematology consultation for complex cases to rule out other causes of anemia. 1