Health Library Home>Wellness Centers>Food & Nutrition>Article

Iron

See also:

Image for iron Iron is a mineral found in meats, eggs, milk, vegetables, grains, and other plant foods. It exists in 2 forms—heme and nonheme. Heme iron is found in animal source. Nonheme iron comes from plant sources. The body absorbs heme iron easier than nonheme iron.

Functions

Iron plays a number of roles in the body including:

Recommended Intake

Iron needs are greatest during times of rapid growth. This is common in childhood, teen years, and pregnancy. Women also have higher requirements than men. It is needed to replace the iron that is lost with monthly periods. Daily recommendations include:

Age Group Recommended Dietary Allowance (RDA)
(mg/day)
Male Female
0-6 months No RDA;
Adequate Intake (AI) = 0.27
No RDA;
Adequate Intake (AI) = 0.27
7-12 months 11 11
1-3 years 7 7
4-8 years 10 10
9-13 years 8 8
14-18 years 11 15
19-50 years 8 18
51+ years 8 8
Pregnancy n/a 27
Lactation, equal to or less than 18 years n/a 10
Lactation, 19-50 years n/a 9

Iron Deficiency

People who are at higher risk for low levels of iron include:

Iron-Deficiency Anemia

Low iron can lead to anemia. Symptoms of anemia include:

Iron can be increased with changes to the diet. Iron supplements may be needed if the diet is not enough.

Iron Toxicity

Iron is toxic at high levels. The body is not effective at getting rid of excess iron. This makes it is possible for iron to build up. Iron pills and supplements for adults can cause poisoning in children.

Symptoms of iron toxicity include:

Major Food Sources

Much of the iron in our diet comes from foods, such as breads and cereals that are fortified with iron.

Food Sources of Mostly Heme Iron

Food Serving size Iron content
(mg)
Beef liver, cooked 3 ounces 5
Oysters, cooked 3 ounces 8
Turkey breast, roasted 3 ounces 1
Chicken, roasted, meat and skin 3 ounces 1
Tuna, fresh bluefin, cooked, dry heat 3 ounces 1

Food Sources of Nonheme Iron

Food Serving size Iron content
(mg)
Ready-to-eat cereal, 100% iron fortified ¾ cup 18.0
Lentils, boiled ½ cup 3
Beans, kidney, mature, boiled ½ cup 2
Tofu, raw, firm ½ cup 3
Spinach, boiled, drained ½ cup 3
Whole wheat bread 1 slice 1

Tips for Increasing Your Iron Intake

Your body will absorb more iron from foods when your iron stores are low. It will also absorb less when you have enough iron in your body.

Other factors that will affect how much iron you absorb from foods include:

To increase intake and absorption of dietary iron:

RESOURCES:

Eat Right—Academy of Nutrition and Dietetics
http://www.eatright.org

Vegetarian Resource Group
http://www.vrg.org

CANADIAN RESOURCES:

Dietitians of Canada
http://www.dietitians.ca

Health Canada
http://www.hc-sc.gc.ca

REFERENCES:

Dietary supplement fact sheet: iron. Office of Dietary Supplements website. Available at:https://ods.od.nih.gov/factsheets/Iron-HealthProfessional. Updated December 7, 2018. Accessed January 13, 2019.

Iron deficiency anemia in adults. EBSCO DynaMed website. Available at:https://www.dynamed.com/topics/dmp~AN~T115986/Iron-deficiency-anemia-in-adults. Updated August 16, 2018. Accessed January 13, 2019.

Iron deficiency anemia in children. EBSCO DynaMed website. Available at:https://www.dynamed.com/topics/dmp~AN~T435307/Iron-deficiency-in-children-infancy-through-adolescence. Updated December 4, 2018. Accessed January 13, 2019.

Last reviewed April 2018 by Michael Woods, MD  Last Updated: 1/13/2019