Iron: Why You Need It, Where to Get It, and Too Little or Too Much

Iron is a mineral the body needs for growth and development. It is used to make hemoglobin, the protein in red blood cells that carries oxygen from the lungs to the rest of the body, and it is also important for healthy muscles, bone marrow and organs and for making some hormones.

Where iron comes from

Iron occurs naturally in many foods and is added to some fortified products. Good sources include:

• lean meat, seafood and poultry;
• iron-fortified breakfast cereals and breads;
• white beans, lentils, spinach, kidney beans and peas; and
• nuts and some dried fruits, such as raisins.

It is also sold as a supplement, on its own or in many multivitamin and mineral products.

Too little iron

Most people in the United States get enough iron. How much you need depends on your age, your sex and whether your diet is mostly plant-based. Low iron can come from blood loss, a poor diet or trouble absorbing iron from food. People more likely to run low include those who:

• have heavy periods;
• are pregnant or breastfeeding;
• are infants, especially if born early or at low birth weight;
• donate blood often;
• have cancer, certain digestive diseases or heart failure;
• are on kidney dialysis; or
• absorb iron poorly because of celiac disease, ulcerative colitis, Crohn's disease, Helicobacter pylori infection or weight-loss surgery.

Too little iron can lead to iron-deficiency anemia. It may cause no symptoms at first, but over time it can bring fatigue, shortness of breath and trouble with memory and concentration. It is usually treated with iron supplements.

Too much iron

Too much iron can harm the body. A healthy person who takes too many iron supplements may have constipation, nausea, vomiting, abdominal pain and diarrhea. Higher levels can cause ulcers, and extremely high levels can lead to organ damage, coma and death.

Hemochromatosis, an inherited disease, causes too much iron to build up in the body. It is usually treated by regularly removing blood, and with it iron, from the body.

Sources

• MedlinePlus, U.S. National Library of Medicine, "Iron" (summary from the National Institutes of Health Office of Dietary Supplements): https://medlineplus.gov/iron.html