What over-the-counter iron supplement can be taken for iron deficiency anemia with Hb 11.8 g/dL, MCV 92.5 fL, MCH 30.6 pg, RDW-SD 54.1 fL, and RDW-CV 15.9%?

Over-the-Counter Iron Supplementation Recommendation

Start with ferrous sulfate 200 mg once or twice daily, which provides approximately 65 mg of elemental iron per dose and is the most cost-effective first-line oral iron supplement. 1

Laboratory Interpretation

Your lab values show:

• Hemoglobin 11.8 g/dL: Mild anemia 1
• MCV 92.5 fL: Normal (normocytic) 1
• Elevated RDW-CV 15.9%: Suggests mixed cell populations or early iron deficiency 1

This pattern indicates possible early or evolving iron deficiency, or iron deficiency combined with another condition (such as inflammation), rather than classic microcytic iron deficiency anemia. 1, 2

Specific Oral Iron Formulations

Ferrous salts are the preferred first-line options: 1

• Ferrous sulfate: 200 mg tablets (65 mg elemental iron) - most economical at $0.30-$4.50 per 30 pills 1
• Ferrous fumarate: 150-106 mg elemental iron per tablet - costs approximately $3.90 per 30 pills 1
• Ferrous gluconate: 27-38 mg elemental iron per tablet - costs $1.50-$3.30 per 30 pills 1

Optimal Dosing Strategy

Take iron once daily on an empty stomach for maximum absorption. 1 Recent evidence shows that:

• Once-daily dosing is as effective as multiple daily doses because hepcidin (which blocks iron absorption) remains elevated for 48 hours after each dose 1
• Lower doses (50-100 mg elemental iron daily) may be equally effective and better tolerated than traditional higher doses 1
• If side effects occur, consider every-other-day dosing, which may improve tolerance 1, 3

Enhancing Absorption

Take with 500 mg vitamin C (ascorbic acid) to enhance iron absorption, especially if inflammation is present. 1, 2 This allows iron absorption even when calcium or fiber is present in meals. 1

Avoid these absorption inhibitors within 1 hour of taking iron: 1, 2

• Tea and coffee (powerful inhibitors) 1
• Calcium supplements 1, 2
• High-fiber foods 1, 2

Alternative if Ferrous Salts Not Tolerated

If you experience gastrointestinal side effects (constipation in 12%, diarrhea in 8%, nausea in 11% of patients): 1

• Ferrous bisglycinate: 25 mg elemental iron per tablet - costs approximately $2.40 per 30 pills and may be better tolerated 1
• Polysaccharide-iron complex: Variable elemental iron content - costs approximately $4.20 per 30 pills 1
• Taking iron with meals: Reduces absorption but improves tolerance 1, 2

Treatment Duration and Monitoring

Continue oral iron for 3 months after hemoglobin normalizes to replenish iron stores. 1, 2

Expected response: 2

• Hemoglobin should increase by at least 1 g/dL within 2 weeks 1, 2
• Total increase of approximately 2 g/dL after 3-4 weeks 2

If no response occurs within 2 weeks, consider: 1, 2

• Poor compliance 2
• Continued blood loss 2
• Malabsorption 2
• Concurrent vitamin B12 or folate deficiency 2
• Need for intravenous iron 1

Important Caveats

Your normocytic anemia (normal MCV) with elevated RDW suggests you may have: 1, 2

• Early iron deficiency (before MCV drops) 1
• Combined iron deficiency with anemia of chronic disease/inflammation 2
• Mixed nutritional deficiencies 2

If you have underlying inflammation, your response to oral iron may be blunted due to elevated hepcidin levels blocking iron absorption. 2 In this case, intravenous iron may ultimately be needed if oral therapy fails. 1, 2

Underlying causes must be identified and treated - iron supplementation alone is insufficient without addressing the source of iron loss or malabsorption. 1