This is a general overview. For more in-depth information, see our health professional fact sheet.
What is Iron and Why is it Essential?
Iron is a vital mineral crucial for human growth and development. It plays a central role in creating hemoglobin, a protein within red blood cells that is responsible for transporting oxygen from your lungs to every part of your body. Additionally, iron is necessary for the production of myoglobin, a protein that supplies oxygen to muscles. Beyond oxygen transport, iron is also used by the body to synthesize various hormones.
Understanding Your Daily Iron Needs
The recommended daily intake of iron varies based on factors like age, sex, and dietary habits, particularly whether you follow a plant-based diet. The following table outlines the average daily recommended amounts in milligrams (mg). It’s important to note that vegetarians, who avoid meat, poultry, and seafood, require nearly double the iron amounts listed due to the lower absorption rate of nonheme iron found in plant-based foods compared to heme iron from animal sources.
| Life Stage | Recommended Amount |
|---|---|
| Birth to 6 months | 0.27 mg |
| Infants 7–12 months | 11 mg |
| Children 1–3 years | 7 mg |
| Children 4–8 years | 10 mg |
| Children 9–13 years | 8 mg |
| Teen boys 14–18 years | 11 mg |
| Teen girls 14–18 years | 15 mg |
| Adult men 19–50 years | 8 mg |
| Adult women 19–50 years | 18 mg |
| Adults 51 years and older | 8 mg |
| Pregnant teens | 27 mg |
| Pregnant women | 27 mg |
| Breastfeeding teens | 10 mg |
| Breastfeeding women | 9 mg |
Top Food Sources to Meet Your Daily Iron Requirement
Iron is naturally present in a wide array of foods and is also added to certain fortified food products. Incorporating a variety of these foods into your diet can help you achieve your recommended daily intake of iron:
- Lean meats, seafood, and poultry: Excellent sources of heme iron, which is easily absorbed by the body.
- Iron-fortified breakfast cereals and breads: A convenient way to boost iron intake, especially for non-heme iron.
- Legumes: White beans, lentils, kidney beans, and peas are good plant-based sources of iron.
- Spinach and other leafy greens: While non-heme iron, spinach contributes to overall iron intake.
- Nuts and dried fruits: Raisins and other dried fruits, along with nuts, offer non-heme iron.
Food iron exists in two forms: heme and nonheme. Heme iron is predominantly found in animal products like meat, seafood, and poultry and is more readily absorbed by the body. Nonheme iron is found in plant-based foods and iron-fortified products.
To enhance nonheme iron absorption, consume it alongside heme iron sources or foods rich in vitamin C. Vitamin C-rich foods include citrus fruits, strawberries, sweet peppers, tomatoes, and broccoli. This combination can significantly improve your body’s ability to utilize iron from plant-based sources.
Iron Supplements: When Are They Necessary?
Iron is available in numerous multivitamin/mineral supplements and as standalone iron supplements. Common forms of iron in supplements include ferrous sulfate, ferrous gluconate, ferric citrate, or ferric sulfate. It’s crucial to be aware that dietary supplements containing iron carry a warning label advising that they should be kept out of children’s reach. Accidental overdose of iron supplements is a leading cause of fatal poisoning in children under the age of 6.
Are You Getting Enough Iron Daily?
While most individuals in the United States obtain sufficient iron, certain populations are at a higher risk of iron deficiency:
- Teenage girls and women experiencing heavy menstrual periods: Blood loss can deplete iron stores.
- Pregnant women and teenagers: Increased iron needs to support both mother and developing baby.
- Infants, particularly premature or low-birth-weight babies: Infants have high iron requirements for growth.
- Frequent blood donors: Regular blood donation can reduce iron levels.
- Individuals with cancer, gastrointestinal (GI) disorders, or heart failure: These conditions can impact iron absorption or increase iron loss.
Consequences of Insufficient Daily Iron Intake
In the short term, mild iron deficiency may not present noticeable symptoms as the body draws upon stored iron in muscles, liver, spleen, and bone marrow. However, prolonged insufficient iron intake leads to iron deficiency anemia. This condition is characterized by smaller red blood cells with less hemoglobin, resulting in reduced oxygen transport throughout the body.
Symptoms of iron deficiency anemia can include gastrointestinal upset, weakness, fatigue, low energy levels, and difficulties with concentration and memory. Furthermore, iron deficiency weakens the immune system, making individuals more susceptible to infections and reducing physical and cognitive performance. Infants and children with iron deficiency anemia may experience learning disabilities.
Iron deficiency is a prevalent issue, especially among young children, women under 50, and pregnant women. Risk factors also include vegetarian diets, blood loss, GI diseases affecting nutrient absorption, and poor dietary habits.
Health Benefits of Adequate Daily Iron
The primary health benefit of ensuring a Daily Serving Of Iron is the prevention of iron deficiency anemia and its associated complications. Ongoing research continues to explore the broader health implications of iron.
Iron’s Role During Pregnancy
Pregnancy significantly increases a woman’s blood volume, necessitating higher iron intake to support both her own body and the developing fetus. Inadequate iron during pregnancy elevates the risk of iron deficiency anemia in the mother and increases the infant’s risk of low birth weight, premature birth, and iron deficiency. Furthermore, insufficient iron may negatively impact the infant’s brain development. Pregnant women should consult their healthcare provider about potential iron supplementation.
Iron for Infants and Toddlers
Iron deficiency anemia in infants can have serious consequences for psychological development, potentially leading to delayed development, social withdrawal, and attention deficits. Full-term infants between 6 to 9 months are at risk of iron deficiency unless they consume iron-enriched solid foods or iron-fortified formula.
Iron and Anemia of Chronic Disease
Certain chronic conditions like rheumatoid arthritis, inflammatory bowel disease, and some cancers can disrupt the body’s ability to utilize stored iron. In these cases, increasing iron intake through diet or supplements is usually ineffective in resolving the anemia. Treatment focuses on managing the underlying chronic disease.
Potential Risks of Excessive Iron Intake
Yes, excessive iron intake can be detrimental to health. High doses of iron supplements, especially when taken on an empty stomach, can cause gastrointestinal distress, including stomach upset, constipation, nausea, abdominal pain, vomiting, and diarrhea. Very high iron levels can lead to more severe issues such as inflammation of the stomach lining and ulcers. Excess iron can also interfere with zinc absorption. Extremely high doses (in the hundreds or thousands of mg) can result in organ failure, coma, seizures, and even death. Child-resistant packaging and warning labels on iron supplements have significantly reduced accidental iron poisonings in children.
Hemochromatosis, an inherited condition, causes the body to accumulate toxic levels of iron. Without treatment, hemochromatosis can lead to serious complications such as liver cirrhosis, liver cancer, and heart disease. Individuals with this condition should avoid iron and vitamin C supplements.
The daily upper limits for iron intake from all sources (food, beverages, and supplements) are provided below. Medical professionals may prescribe iron doses exceeding these upper limits for short-term treatment of iron deficiency.
| Ages | Upper Limit |
|---|---|
| Birth to 12 months | 40 mg |
| Children 1–13 years | 40 mg |
| Teens 14–18 years | 45 mg |
| Adults 19+ years | 45 mg |
Iron Interactions with Medications and Supplements
Iron supplements can interact with certain medications and other dietary supplements. Examples of potential interactions include:
- Antacids and Proton Pump Inhibitors (PPIs): These medications reduce stomach acid, which is necessary for iron absorption.
- Tetracycline and Quinolone Antibiotics: Iron can interfere with the absorption of these antibiotics.
- Levothyroxine: Iron supplements can reduce the effectiveness of this thyroid medication.
- Calcium Supplements: Calcium can inhibit iron absorption when taken concurrently.
Always inform your doctor, pharmacist, and other healthcare providers about all dietary supplements and prescription or over-the-counter medications you are taking to assess potential interactions.
Iron and a Balanced Diet
The Dietary Guidelines for Americans emphasize obtaining most nutrients from food and beverages. Whole foods provide a complex array of vitamins, minerals, dietary fiber, and other beneficial components. Fortified foods and dietary supplements can be valuable tools when dietary intake alone is insufficient to meet nutrient needs, such as during pregnancy. For further information on building a healthy dietary pattern, consult the Dietary Guidelines for Americans and the USDA’s MyPlate.
Further Resources on Iron
Disclaimer
This fact sheet from the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) is intended for informational purposes and should not substitute professional medical advice. Consult your healthcare providers (doctor, registered dietitian, pharmacist, etc.) regarding any questions or concerns about dietary supplements and your overall health. Mention of specific products, services, organizations, or professional societies in this publication does not imply endorsement by the ODS.
Updated: August 17, 2023 History of changes to this fact sheet
