Dietary Iron and Iron Supplements

Iron is a mineral that's necessary for life. Iron plays a key role in the making of red blood cells, which carry oxygen. You can get iron from food and from supplements. If you don't have enough iron, you may develop anemia, a low level of red blood cells.

Why do people take iron?

Iron supplements are most often used for certain types of anemia. Anemia can cause fatigue and other symptoms. If you have symptoms of anemia, seek care from your health care provider. Don't try to treat it on your own.

Iron supplements are often used to treat anemia caused by:

Iron supplements have also been studied for treatment of ADHD. While early data suggested a benefit, more study is needed before iron can be recommended for ADHD.

Iron supplements are commonly recommended for infants and toddlers, teenage girls, and women who are pregnant or of childbearing age to help prevent anemia. Before taking an iron supplement, ask your health care provider if it is right for you.

How much iron should you take?

The recommended dietary allowance (RDA) includes the iron you get from both the food you eat and any supplements you take.


Recommended Dietary Allowance (RDA)


7-12 months

11 mg/day

1-3 years

7 mg/day

4-8 years

10 mg/day

9-13 years

8 mg/day


14-18 years

15 mg/day

19-50 years

18 mg/day

51 years and over

8 mg/day


27 mg/day


Under 19 years: 10 mg/day

19 years and over: 9 mg/day


14-18 years

11 mg/day

19 years and up

8 mg/day

Take iron supplements with a full glass of water or food. Strict vegetarians may need to take in higher levels of iron.

At high doses, iron is toxic. For adults and children ages 14 and up, the upper limit -- the highest dose that can be taken safely -- is 45 mg a day. Children under age 14 should not take more than 40 mg a day.

The American Academy of Pediatrics suggests that -- starting at 4 months of age -- breastfed infants should be supplemented with 1 mg/kg per day of oral iron. This should continue until iron-containing complementary foods, such as iron-fortified cereals, are introduced in the diet.

Also beginning at 4 months of age, partially breastfed infants (more than half of their daily feedings as formula or milk) who are not receiving iron-containing complementary foods should receive 1 mg/kg per day of supplemental iron.

Ask your health care provider how much iron supplement you or your child should take, if any.


Can you get iron naturally from foods?

For most people, a good diet provides enough iron. Natural food sources of iron include:

  • Meat, fish, and poultry
  • Vegetables, like spinach, kale, and broccoli
  • Dried fruits and nuts
  • Beans, lentils, and peas

Iron is also added to many fortified foods, such as cereals and enriched breads.

Iron from animal sources is absorbed better by the body. However, you can help your body absorb plant-based iron by eating a fruit or vegetable that is high in vitamin C (for example, red bell peppers, kiwis, oranges).

What are the risks of taking iron?

  • Side effects. Taken at normal doses, iron supplements may cause upset stomach, stool changes, and constipation.
  • Risks. Don't start taking iron supplements unless your health care provider tells you that you need them. That's especially true if you have a chronic health condition. Women who plan to become pregnant should also check with a health care provider before they start daily iron supplements.
  • Interactions. Iron can interact with many different drugs and supplements. They include antacids and proton pump inhibitors, antibiotics, calcium, and others. If you take daily medicine, ask your health care provider if it’s safe for you to take iron supplements.
  • Overdose. Iron overdose is a common cause of poisoning in children. It can be fatal. Signs of an iron overdose include severe vomiting and diarrhea, stomach cramps, pale or bluish skin and fingernails, and weakness. Treat these signs as a medical emergency. Call poison control and get medical help immediately.
WebMD Medical Reference Reviewed by David Kiefer, MD on April 27, 2015


Baker, R. Pediatrics, November 2010.
Longe, J., ed. The Gale Encyclopedia of Alternative Medicine, second edition, 2004.
Natural Standard Patient Monograph: "Iron."
Office of Dietary Supplements: "Iron."
UpToDate: "Approach to the Adult Patient With Anemia."

Centers for Disease Control: "Iron and Iron Deficiency."

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