Type
mineral
Dosage Summary
RDA is ~8 mg for men & post-menopausal women, 18 mg for menstruating women, 27 mg in pregnancy. Best sources: red meat, liver, shellfish. Avoid excess intake, especially unbound iron, and test ferritin before supplementing.
Innate Stores
Forms
food, capsule, tablet, liquid
Iron is a critical mineral essential for oxygen transport via hemoglobin and energy production in the mitochondria. It also plays key roles in neurotransmitter synthesis, immune function, and DNA replication.
The primary concern with iron is balancing adequate intake with avoiding excess. Iron overload from unbound iron in "enriched foods" is more common than recognized, especially in men and post-menopausal women, as the body lacks efficient excretion mechanisms leading to accumulation in tissues and subsequent systemic inflammation. Excess iron acts as a pro-oxidant, generating harmful free radicals through the Fenton reaction, damaging tissues and accelerating aging.
Key Functions
- Oxygen transport via hemoglobin
- Cellular energy production in mitochondria
- Neurotransmitter synthesis (dopamine, serotonin)
- DNA synthesis and repair
- Immune system function
Best Food Sources
- Heme iron (animal sources):
- Grass-fed red meat (3-4 mg per 100g)
- Organ meats, especially liver (6-9 mg per 100g)
- Shellfish, particularly oysters and clams
Iron requirements vary significantly by sex, age, and individual factors. Adult men and post-menopausal women need approximately 8 mg daily, while menstruating women require 18 mg daily. Pregnant women have increased needs of 27 mg daily. Always assess individual status and opt for heme-iron rich food over supplements.
Important Notes
- Test ferritin, transferrin saturation, and hemoglobin before supplementing
- Heme iron (animal sources) is 2+ times more bioavailable than non-heme iron
- Avoid consuming iron with foods rich in calcium, tannins (tea), or phytates
- Consider regular blood donation for men and post-menopausal women if ferritin is high
Warning Signs
- Deficiency: Fatigue, weakness, pale skin, brittle nails, cold intolerance
- Excess: Joint pain, fatigue, skin darkening, liver dysfunction, heart issues
- Ferritin levels above 150 ng/mL in men or post-menopausal women may indicate excess
- Avoid blind supplementation without testing
- Genetic conditions like hemochromatosis increase iron absorption risk
Note: Optimal dosage may vary based on individual factors like age, weight, health conditions, and goals. It's always best to start with a lower dose and gradually increase as needed.