What treatment is recommended for iron deficiency anemia with an iron saturation of 18% and an iron level of 44 μg/dL?

Management of Iron Deficiency with Iron Saturation 18% and Serum Iron 44 μg/dL

You should initiate oral iron supplementation with ferrous sulfate 200 mg three times daily (or equivalent formulations like ferrous fumarate or ferrous gluconate) to correct the iron deficiency and replenish body stores. 1

Understanding Your Iron Status

Your laboratory values indicate iron deficiency:

• Iron saturation of 18% is below the normal range (20-50%) and indicates insufficient iron available for red blood cell production 1
• Serum iron of 44 μg/dL is at the lower end of normal (50-175 μg/dL), confirming inadequate circulating iron 1

These findings warrant iron supplementation regardless of whether frank anemia is present, as iron deficiency even without anemia can cause significant symptoms including fatigue and reduced physical performance. 1

Recommended Treatment Approach

First-Line: Oral Iron Supplementation

Standard dosing:

• Ferrous sulfate 200 mg three times daily (providing approximately 65 mg elemental iron per dose) 1, 2
• Alternative equally effective options: ferrous gluconate or ferrous fumarate at equivalent elemental iron doses 1

Recent evidence suggests lower doses may be equally effective with better tolerance:

• For mild, asymptomatic deficiency: 100 mg elemental iron once daily may be sufficient 3
• For symptomatic or more severe deficiency: 200 mg elemental iron daily 3
• If gastrointestinal side effects occur (constipation, nausea, diarrhea), consider alternate-day dosing, which recent data shows improves absorption and reduces adverse effects 1

Duration of Treatment

• Continue iron supplementation for 3 months after hemoglobin normalization to adequately replenish iron stores 1
• Expect hemoglobin to rise by approximately 2 g/dL after 3-4 weeks of treatment 1

Enhancing Absorption

• Co-administer with vitamin C (ascorbic acid) to enhance iron absorption, particularly important with non-heme iron sources 1
• Avoid tea and coffee around meal times as they impair iron absorption 1

When to Consider Intravenous Iron

Parenteral iron should be reserved for specific situations 1:

• Intolerance to at least two different oral iron preparations
• Non-compliance with oral therapy
• Malabsorption conditions (celiac disease, inflammatory bowel disease, post-bariatric surgery) 1, 4
• Failure to respond to adequate oral therapy after 4 weeks despite compliance 1
• Severe anemia requiring rapid correction 1

Note: Intravenous iron is more expensive, carries rare but serious anaphylaxis risk, and provides no faster hemoglobin rise than oral preparations when oral therapy is tolerated 1

Monitoring Response

• Recheck hemoglobin and iron studies after 3-4 weeks to confirm response (expect 2 g/dL hemoglobin increase) 1
• If no response occurs despite compliance and absence of acute illness, further evaluation is needed including mean corpuscular volume (MCV), red cell distribution width (RDW), and ferritin 1
• Do not recheck ferritin earlier than 8-10 weeks after starting treatment, as levels can be falsely elevated initially 1

Investigation for Underlying Cause

The presence of iron deficiency warrants investigation for the source of iron loss, particularly in specific populations 1, 5:

• Men and postmenopausal women: Should undergo gastrointestinal evaluation (upper endoscopy and colonoscopy) as iron deficiency in these groups is abnormal and may indicate occult bleeding from malignancy 1, 5, 4
• Premenopausal women: If menstrual loss is the likely cause and patient is under 40 years without alarm symptoms, investigation may be deferred 1, 4
• Screen for celiac disease with tissue transglutaminase antibody (IgA) and total IgA level, as this is a common cause of iron malabsorption 1, 4

Common Pitfalls to Avoid

• Do not assume dietary deficiency alone without investigating for blood loss, especially in men and postmenopausal women 5
• Do not stop iron supplementation once hemoglobin normalizes—continue for 3 additional months to replenish stores 1
• Failure to respond to oral iron is usually due to poor compliance, continued blood loss, misdiagnosis, or malabsorption—not inadequate dosing 1
• Do not use intravenous iron as first-line therapy unless specific indications exist, as oral therapy is safer and equally effective when tolerated 1