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Publication #FCS8704

Facts About Iron1

Linda B. Bobroff and Jennifer Hillan2

Why do we need iron?

Iron is a mineral, and it is found in every cell in the body. It's an important part of red blood cells, which hold and carry oxygen to all of the cells. Our cells use oxygen to make energy from the food we eat. Iron also is needed to keep the immune system healthy and help brain cells work normally.

What happens if we do not get enough iron?

Iron deficiency is the most common nutritional deficiency in the world. Severe iron deficiency can lead to one type of anemia. Iron deficiency can be caused by several factors, including:

  • not getting enough iron in the diet

  • not absorbing iron properly

  • losing blood from injury or illness

Figure 1. 

When your body does not have enough iron you may feel tired and have problems concentrating on tasks.


John Howard/Photodisc/

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Without adequate iron, red blood cells cannot carry enough oxygen to other cells in the body. Cells that do not get oxygen cannot function properly.

Signs of an iron deficiency include:

  • feeling tired

  • infections

  • muscle weakness

  • difficulty concentrating

How much iron do we need?

The following table lists recommended daily intakes of iron:

Table 1. 

Recommended daily intakes of iron.

Life Stage

Amount (mg/day)

Men, ages 19+


Women, ages 19–50


Women, ages 51+





Ages 14–18

Ages 19–50



mg = milligrams

*vegetarians in this life stage need 14 mg/d

**vegetarians in this life stage need 32 mg/d

How can we get enough iron?

Both animal and plant foods contain iron, but our bodies absorb the iron from meats and other foods from animals better than iron from plant foods. To increase the amount of iron that is absorbed from plant foods, eat them with foods high in vitamin C or with meat, poultry, or fish. Foods high in vitamin C include oranges, peppers, and strawberries.

Figure 2. 

Meat, poultry, and fish are naturally rich sources of iron. The form of iron in these foods is well-absorbed.


Aris Sanjaya/iStock/

[Click thumbnail to enlarge.]

Figure 3. 

Whole grain foods are fortified with iron. To increase absorption of this form of iron, eat these foods with a source of vitamin C, like orange juice, cantaloupe, or bell peppers.


Tetra Images/

[Click thumbnail to enlarge.]

Table 2. 

Food examples with iron amounts in mg/serving (US Department of Health & Human Services, 2016).




Fortified cereal, 1 cup


White beans, 1 cup


Lentils, boiled and drained, ½ cup


Spinach, boiled and drained, ½ cup


Kidney beans, canned, ½ cup


Lean bottom round, broiled, 3 ounces


Potato, baked, with skin, 1 medium


Cashews, roasted, 1 ounce


Chicken, roasted with skin, 3 ounces


Raisins, ¼ cup


Bread, whole wheat, 1 slice


mg = milligrams

What about supplements?

Some groups of people need iron supplements. These include pregnant women and persons with an iron deficiency. People who do not get enough iron from food may choose to take an iron supplement.

Be sure to keep supplements out of the reach of children, because an overdose of iron can be fatal.

How much is too much?

Too much iron can be toxic to the body. It can cause nausea, vomiting, constipation, or diarrhea. Over a long period of time, too much iron in the body can damage the liver. In addition, too much iron from supplements can reduce the amount of zinc that is absorbed.

You should not get more than 45 mg of iron per day from food and supplements.

Where can I get more information?

The Family and Consumer Sciences (FCS) agent at your local Extension office may have written information and nutrition classes for you to attend. Also, your doctor or a registered dietitian (RD) can provide reliable information.

Reliable nutrition information also may be found on the Internet at the following sites:


US Department of Health & Human Services. (2016). Iron: Dietary supplement fact sheet. Health Information. Accessed on March 14, 2017.



This document is FCS8704, one of a series of the Department of Family, Youth and Community Sciences, UF/IFAS Extension. Original publication date June 2001. Revised November 2017. Visit the EDIS website at


Linda B. Bobroff, PhD, RDN, professor, Department of Family, Youth and Community Sciences; and Jennifer Hillan, MSH, RD, LD/N, former ENAFS nutrition educator/trainer, Department of Family, Youth and Community Sciences; UF/IFAS Extension, Gainesville, FL 32611.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.