Mineral

Iron

Iron (Fe, element 26)

Evidence TierAWADA NOT PROHIBITED

tuneTypical Dose

40-80 mg elemental iron every other day for typical non-urgent repletion. Daily higher-dose protocols are still used when clinically indicated

watchEffect Window

Fatigue improvement in 2-4 weeks. Ferritin repletion in 3-6 months.

check_circleCompliance

WADA NOT PROHIBITED

Overview

Clinical Summary

Iron is essential for hemoglobin, oxygen transport, and cellular energy metabolism. It is used to correct low ferritin or iron deficiency anemia that causes fatigue, poor exercise tolerance, and cognitive symptoms.

Restoring iron stores improves hemoglobin, reduces fatigue, and improves exercise capacity when iron status is low. Cognitive performance and restless legs symptoms can improve in low-ferritin individuals. Modern dosing studies also support every-other-day oral iron as a practical repletion strategy with similar short-term effectiveness to daily dosing in uncomplicated deficiency states. Minority benefits include improved pregnancy outcomes when deficiency is present. Excess iron is harmful, so net benefit depends on lab-guided correction and careful dosing to avoid overload.

Central atom in heme for hemoglobin and myoglobin enabling oxygen transport. Cofactor in mitochondrial ATP production and DNA synthesis enzymes. Repletion restores oxygen delivery to energy-dependent tissues.

Outcomes

What This Is Expected To Influence

Primary Outcomes

Corrects iron deficiency anemia (standard medical treatment)
Restores hemoglobin and ferritin to normal ranges in deficient individuals

Secondary Outcomes

Reduces fatigue associated with iron deficiency
May reduce restless legs syndrome symptoms when ferritin is low

Safety

Contraindications and Interactions

Contraindications

Hemochromatosis
Hemolytic anemias
Iron overload disorders
Active infection (relative)

Side effects

Constipation
Nausea
Abdominal discomfort
Black stools

Interactions

Levothyroxine sodium (Probable/Moderate) - Iron may bind to and reduce the absorption of levothyroxine.
Penicillamine (Probable/Moderate) - Iron may bind to and reduce the absorption of penicillamine.
Acid-reducing drugs (Probable/Moderate) - Drugs that increase stomach pH (for example PPIs and H2 blockers) can reduce iron absorption.
Levodopa (Probable/Moderate) - Iron may bind to and reduce the absorption of levodopa.
Calcium (Probable/Moderate) - Calcium may reduce the absorption of iron when administered together, but this may depend on the type of calcium supplement.
Captopril (Possible/Moderate) - Iron may bind to and reduce the absorption of captopril.
Methyldopa (Possible/Moderate) - Iron may bind to and reduce the absorption of methyldopa.
Carbidopa (Possible/Moderate) - Iron may bind to and reduce the absorption of carbidopa.
Tetracyclines (Probable/Moderate) - Iron can chelate tetracycline antibiotics and reduce drug absorption.
Fluoroquinolones (Probable/Moderate) - Iron can chelate fluoroquinolone antibiotics and reduce drug absorption.
Bisphosphonates (Probable/Moderate) - Iron can reduce bisphosphonate absorption when co-administered.

Avoid if

No documented iron deficiency
Hemochromatosis or other iron overload disorders
Active untreated infection
Unexplained elevated ferritin

Evidence

Study-level References

iron-SRC-001Narrative/clinical review

Sourceopen_in_new

Pasricha et al., 2021, The Lancet (iron deficiency and anemia review)

Population: Iron-deficient and/or iron-deficiency anemia populations across common risk groups

Dose protocol: Oral elemental iron protocols with biomarker follow-up (ferritin/hemoglobin)

Key findings: Oral iron is first-line and effective for confirmed deficiency and deficiency anemia. Fatigue and functional improvement are expected with repletion in deficient users. Overtreatment without deficiency increases harm potential due iron accumulation risk.

Notes: Prioritize lab-confirmed deficiency before supplementation and monitor ferritin/hemoglobin longitudinally.

Paper content

Oral iron is first-line and effective for confirmed deficiency and deficiency anemia. Fatigue and functional improvement are expected with repletion in deficient users. Overtreatment without deficiency increases harm potential due iron accumulation risk.

iron-SRC-002Comparative clinical study

Sourceopen_in_new

Kaynar LA, Gökçen S, Can F, Yeğin ZA, Özkurt ZN, Yağcı M. Comparison of daily oral iron replacement therapy with every other day treatment in female reproductive age patients with iron-deficiency anemia. Ann Hematol. 2022;101(7):1459-1464. doi:10.1007/s00277-022-04835-6. PMID:35460388.

Population: Premenopausal women of reproductive age with iron-deficiency anemia.

Dose protocol: Ferrous sulfate 80 mg twice daily given either daily or every other day for 2 months

Key findings: Both regimens improved hemoglobin, ferritin, and transferrin saturation. Every-other-day dosing produced similar short-term correction, supporting it as a practical option when tolerability or adherence is limiting.

Notes: Useful for modernizing protocol guidance. The trial supports comparable effectiveness, not superiority, and the population was limited to reproductive-age women with IDA.