Health Topic

Iron

Our bodies need the right amount of iron to function properly. Read about what can happen when you consume too much or too little of it.

Reviewed Reviewed by a registered pharmacistGeneral information

Important: This page is general information, not medical advice. It does not recommend or prescribe any treatment. Always consult your doctor or pharmacist before starting, stopping or changing any medicine.

About Iron

Iron is a mineral that our bodies need for growth and development. Your body uses iron to make hemoglobin, a protein in red blood cells. Hemoglobin carries oxygen from the lungs to all parts of the body. Iron is also important for healthy muscles, bone marrow, and organ function. Your body also needs iron to make some hormones.

Iron is found naturally in many foods and is added to some fortified food products. Foods that are high in iron include:

  • Lean meat, seafood, and poultry
  • Iron-fortified breakfast cereals and breads
  • White beans, lentils, spinach, kidney beans, and peas
  • Nuts and some dried fruits, such as raisins

Iron is available in supplements, either on its own or as part of many multivitamin/mineral supplements.

Most people in the United States get enough iron. The amount that you need each day depends on your age, your sex, and whether you consume a mostly plant-based diet.

Sometimes people can have trouble getting enough iron. There can be many causes, including blood loss, a poor diet, or a problem absorbing enough iron from foods. Those who are more likely to have low iron include people who:

  • Have heavy periods
  • Are pregnant or breastfeeding
  • Are infants (especially if they were born premature or low birth weight)
  • Are frequent blood donors
  • Have cancer, certain digestive diseases, or heart failure
  • Are on kidney dialysis
  • Have trouble absorbing iron because they: Have a digestive condition such as celiac disease, ulcerative colitis, Crohn's disease, or Helicobacter pylori infection
  • Had weight loss surgery

If you have too little iron, you may develop iron-deficiency anemia. It may not cause symptoms at first, but over time, it can cause fatigue, shortness of breath, and trouble with memory and concentration. Treatment for low iron and iron-deficiency anemia is usually with iron supplements.

Too much iron can damage your body. For example, if you are healthy and take too many iron supplements, you may have symptoms such as constipation, nausea and vomiting, abdominal (belly) pain, and diarrhea. Higher iron levels can cause ulcers. Extremely high levels can lead to organ damage, coma, and death.

A disease called hemochromatosis can cause too much iron to build up in the body. Hemochromatosis is inherited (passed down through families). It is usually treated by removing blood (and iron) from your body on a regular basis.

National Institutes of Health, Office of Dietary Supplements

It sits within Food and Nutrition.

The lead U.S. institute for this subject is the NIH Office of Dietary Supplements.

When to speak to someone. Reading about a topic cannot tell you whether it applies to you. Speak to a doctor or pharmacist if symptoms are severe, sudden, getting worse, or simply not going away — and seek emergency care immediately for chest pain, breathing difficulty, sudden weakness or confusion, or a serious allergic reaction.

Research on Iron

1,871 studies areregistered for this condition on ClinicalTrials.gov, the U.S. National Library of Medicine's public registry. A selection is below — the links go straight to the registry entry, not to a summary of ours.

What a registered study does and does not mean. Registration means a study exists and has been declared publicly. It says nothing about whether the treatment being tested works, is safe, or is available to you. Many studies find no benefit — that is what research is for. Never seek out an experimental treatment on the strength of a registry entry alone.

Research currently under way

Research already completed

Study data from ClinicalTrials.gov, a service of the U.S. National Library of Medicine. Retrieved 2026-07-30. Registry entries are supplied by study sponsors and investigators; ClinicalTrials.gov does not verify their scientific validity. PocketsInfo is not affiliated with, and not endorsed by, the NLM or the NIH.

Where to read more

Rather than paraphrase, we point you to the primary sources. Every link below is to a government health agency, a national institute or a recognised medical body — grouped by what you are trying to find out.

Start Here

  • IronNational Institutes of Health, Office of Dietary Supplements

Diagnosis and Tests

Genetics

Statistics and Research

Clinical Trials

Medical subject headings

Clinicians and researchers index this subject under Iron. These are the terms to use when searching medical literature.

This page is built from the MedlinePlus health topic record for Iron, a service of the U.S. National Library of Medicine (NLM), National Institutes of Health. Information is from MedlinePlus.gov. PocketsInfo is not affiliated with, and is not endorsed by, the NLM or the NIH. Retrieved 30 July 2026.