Iron Liquid Supplement Dosing
The specific milliliter (mL) dose cannot be determined without knowing the elemental iron concentration of your particular liquid iron formulation, but the target is 50-100 mg of elemental iron once daily in the morning on an empty stomach. 1, 2
How to Calculate Your Dose
To determine the correct mL dose, you must:
Check the product label for elemental iron content per mL (e.g., "10 mg elemental iron per mL" or "15 mg/mL") 2
Calculate using this formula:
- Target dose (50-100 mg elemental iron) ÷ concentration per mL = mL to administer
- Example: If your liquid contains 15 mg elemental iron/mL and you need 65 mg:
- 65 mg ÷ 15 mg/mL = 4.3 mL
Recommended Elemental Iron Dosing
For adults with iron deficiency anemia, the optimal dose is 50-100 mg elemental iron once daily, with 65 mg being the most commonly recommended starting dose. 1, 2, 3
Key Dosing Principles:
Once-daily dosing is superior to divided doses because iron doses ≥60 mg stimulate hepcidin levels that reduce subsequent iron absorption by 35-45% for 24 hours 1, 4
Morning administration on an empty stomach maximizes absorption, as the circadian increase in hepcidin is augmented by morning iron doses 5, 4
Maximum recommended dose is 100 mg elemental iron once daily for most adults 1, 3
Optimal Administration Protocol
Take iron in the morning, at least 30-60 minutes before breakfast, with:
- 100 mg vitamin C tablet OR a glass of orange/citrus juice to enhance absorption 5
- If neither available, take with plain water 5
- Remain upright for 30-60 minutes after dosing to prevent pill esophagitis 5
What to Avoid:
- Do NOT take with: milk, tea, coffee, cereals, grains, calcium supplements, antacids, H2 blockers, or proton pump inhibitors—all markedly reduce absorption 5
- Do NOT take afternoon or evening doses after a morning dose, as hepcidin remains elevated 4
Alternative Dosing Strategy
If gastrointestinal side effects occur, consider alternate-day dosing with 120 mg elemental iron every other morning, which increases fractional absorption and reduces side effects while maintaining similar total iron absorption 1, 4
Duration and Monitoring
- Continue for 3-12 weeks to correct anemia and replenish stores 6
- Monitor hemoglobin every 4 weeks until normalized 1
- After hemoglobin normalizes, continue for 2-3 months to replenish iron stores 1
- Lack of ≥10 g/L hemoglobin rise after 2 weeks strongly predicts treatment failure and warrants reassessment 1
Common Pitfall
The most critical error is not knowing your liquid formulation's elemental iron concentration. Iron salts vary dramatically in elemental iron content—ferrous sulfate 200 mg contains 65 mg elemental iron (32.5%), while ferrous gluconate 300 mg contains only 37 mg elemental iron 2. Always verify the elemental iron content per mL on your specific product label before calculating the dose. 2, 3