Iron is an important mineral that your body needs to make hemoglobin, a protein in red blood cells. Red blood cells help carry oxygen throughout your body.

You get iron from certain foods, like red meat and dark, leafy green vegetables, and from dietary supplements.

Low iron levels can cause a condition called anemia, which can lead to symptoms like fatigue, shortness of breath, and pale skin. On the other hand, iron levels that are too high can damage your organs and cause liver disease, heart problems, and diabetes.

This article explores the benefits of iron, some iron-rich foods, and how to make sure you’re getting the right amount of this vital mineral.

Your body needs iron to carry oxygen to the rest of the body. Having adequate levels of iron in your blood supports many healthy bodily functions.

Energy

Iron’s main purpose is to carry oxygen in the hemoglobin of red blood cells to the rest of the body so that your cells can produce energy. In fact, a lack of energy is one of the main symptoms of iron deficiency anemia.

Physical performance and endurance

Iron is essential for the body to transport oxygen to the muscles. Iron deficiency reduces physical performance in athletes, including strength, endurance, power, speed, coordination, and recovery.

Healthy immune system

Iron is vital for a fully functioning immune system. Too little iron may increase your risk of infections.

In pregnancy

During pregnancy, your body needs more iron because the volume of blood in your body increases. Your body uses iron to make blood to supply oxygen to support the growth of your baby.

According to the National Institutes of Health (NIH), the recommended daily allowance for iron depends on your age and sex. Vegetarians, vegans, and those who are pregnant or nursing also have different iron requirements.

The following values are for people who aren’t vegetarians or vegans.

Males

  • 9–13 years: 8 milligrams (mg)
  • 14–18 years: 11 mg
  • 19 years and older: 8 mg

Females

  • 9–13 years: 8 mg
  • 14–18 years: 15 mg
  • 19–50 years: 18 mg
  • 51 years and older: 8 mg
  • while pregnant: 27 mg
  • while lactating at younger than 18 years: 10 mg
  • while lactating at older than 19 years: 9 mg

Children

  • 1–3 years: 7 mg
  • 4–8 years: 10 mg

Infants

  • 0–6 months: 0.27 mg
  • 7–12 months: 11 mg

Iron occurs naturally in many foods, and some food manufacturers also add it to certain fortified products. You can usually get enough iron from your diet by eating a variety of foods, but some people have trouble getting enough iron from the foods they eat.

Factors that affect absorption

Iron has a low bioavailability. This means that the small intestine doesn’t absorb iron from the food you eat in large amounts.

How much iron you absorb depends on many factors, including:

  • the source of the iron
  • other foods you’re eating
  • your overall health and the health of your gastrointestinal tract
  • medications or supplements you’re taking
  • your overall iron status

Eating foods with vitamin C enhances the bioavailability of nonheme iron (see below). On the other hand, certain components — like tannins in coffee, tea, and wine — might block the absorption of iron.

Heme iron vs. nonheme iron

Iron in food occurs in two forms: heme iron and nonheme iron.

Nonheme iron occurs naturally in plant foods as well as meat, seafood, and poultry. Conversely, heme iron only occurs in meat, poultry, and seafood.

Heme iron has a higher bioavailability than nonheme iron.

Iron-fortified foods

Certain foods — like cereals, bread products, orange juice, and rice — are fortified with iron to help boost intake.

Foods that are naturally high in iron include:

  • fish
  • spinach
  • organ meats
  • red meat
  • legumes
  • pumpkin seeds
  • broccoli
  • tofu
  • dark chocolate

Read more about foods high in iron.

Iron is available in many types of supplements and multivitamins. In supplements, iron is usually in the form of ferrous sulfate, ferrous gluconate, and ferrous fumarate.

Keep in mind that the Food and Drug Administration (FDA) doesn’t closely monitor supplements. This means that supplements may contain ingredients not listed on the label or contain ingredients in varying amounts.

It’s best to speak with a doctor before taking supplements and always read the label for the correct dosage.

Who needs iron supplements?

Some people have trouble getting enough iron in their diet.

Before starting supplements, ask a doctor about getting your iron levels checked. Taking iron supplements when you don’t need them could harm your health.

Speak with a doctor about getting your iron levels checked if you:

  • are a female of childbearing age
  • have heavy periods
  • are pregnant
  • donate blood frequently
  • are vegetarian or vegan and don’t replace meat with other iron-rich foods
  • are over 65 years old
  • have cancer, a gastrointestinal condition, or heart failure
  • are an endurance athlete

Infants, especially those born prematurely or experiencing a growth spurt, may also need their iron levels checked.

Who should avoid iron supplements?

Doctors don’t recommend iron supplements if you’re not deficient or don’t have a high risk of developing iron deficiency.

Both too little and too much iron can cause problems.

Risks of too little iron (deficiency)

Not getting enough iron can lead to a condition called anemia. Common symptoms of anemia include tiredness, shortness of breath, lightheadedness, and pale skin.

Risks of too much iron (toxicity)

Too much iron can be dangerous. Doctors don’t recommend iron supplements when you don’t have a diagnosed deficiency or a high risk of developing iron deficiency.

If you have a genetic condition called hemochromatosis, you’re at high risk of iron overload. People with this condition absorb far more iron from food than those without it.

Too much iron can cause the following issues.

Organ damage

Taking in too much iron can lead to a buildup of iron in the liver and other organs, damaging cells and tissues around the body.

Stomach issues

Iron supplements can cause nausea, vomiting, constipation, and stomach pain, especially if you don’t take them with food. Iron pills may also change the color of your stool to dark green or black, but this is normal.

Interactions with medications

Iron supplements can lower the effectiveness of several medications, including:

  • carbidopa and levodopa (Sinemet)
  • penicillamine (Depen Titratabs, Cuprimine)
  • levothyroxine (Synthroid, Levoxyl, Unithroid, Tirosint)

Additionally, proton pump inhibitors are known to decrease iron absorption.

If you’re experiencing any symptoms of iron deficiency anemia — like fatigue, pale skin, or shortness of breath — it’s best to contact a doctor about getting your iron levels checked. This is especially true if you’re at higher risk of iron deficiency, including if you:

  • are pregnant
  • eat a vegetarian or vegan diet
  • are an endurance athlete

Iron is an essential mineral that helps your red blood cells carry oxygen throughout your body. You can usually get enough iron from your diet by eating a variety of foods, but some people have trouble getting enough iron and may need to take supplements.

Be sure to discuss supplements with a doctor before taking them.