- In hemoglobin, carrying oxygen to cells throughout the body
- In myoglobin, holding oxygen within the cells, especially heart and skeletal muscle cells
- Forming collagen, which is the major protein that makes up connective tissue, cartilage, and bone
- Helping fight infection by synthesizing certain enzymes needed for immune function
- Helping convert beta carotene to vitamin A
- Helping make amino acids, which are the building blocks of protein
- Aiding drug detoxification pathways in the liver
- Forming part of an enzyme that is essential for the production of several neurotransmitters
- Synthesizing cellular components that are important to metabolism
Recommended Dietary Allowance
Adequate Intake (AI) = 0.27
Adequate Intake (AI) = 0.27
|Lactation, equal to or less than 18 years||n/a||10|
|Lactation, 19-50 years||n/a||9|
- Women of childbearing years
- Teenage girls
- Infants (depending on their diet)
- Low-income groups
- People with certain gastrointestinal conditions such as celiac disease
- Fatigue: feeling tired all the time or getting tired easily with activities you used to be able to do without difficulty
- Pale skin, especially the pink lining to your lower eyelids, under your fingernails, or your gums
- Glossitis (an inflamed tongue)
- Rapid heartbeat
- A ringing in the ears known as tinnitus
- Unusual cravings for substances like ice, dirt, etc. (called pica)
- Nausea and vomiting
- Diarrhea or constipation
- Abdominal pain
Major Food Sources
Food Sources of Mostly Heme Iron
|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
|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|
Other Health Implications Related to Iron
Heart Disease and Cancer
Tips for Increasing Your Iron Intake
- Heme iron is absorbed more efficiently than nonheme iron.
- Heme iron enhances the absorption of nonheme iron.
- Vitamin C enhances the absorption of nonheme iron.
Some substances decrease the absorption of nonheme iron:
Note: Consuming heme iron and/or vitamin C with nonheme can help compensate for these decreases.
- Oxalic acid, found in spinach and chocolate (However, oxalic acid is broken down with cooking.)
- Phytic acid, found in wheat bran and beans (legumes)
- Tannins, found in tea
- Polyphenols, found in coffee
- Combine heme and nonheme sources of iron.
Eat foods rich in vitamin C with nonheme iron sources. Good sources of vitamin C include:
- Bell peppers
- Oranges and orange juice
- Tomatoes and tomato juice
- Spinach and collard greens
- If you drink coffee or tea, do so between meals rather than with a meal.
- Cook acidic foods in cast iron pots. This can increase iron content up to 30 times.
Academy of Nutrition and Dietetics http://www.eatright.org
Vegetarian Resource Group http://www.vrg.org
Dietitians of Canada http://www.dietitians.ca
Health Canada http://www.hc-sc.gc.ca
Dietary supplement fact sheet: iron. Office of Dietary Supplements website. Available at: http://ods.od.nih.gov/factsheets/iron.asp. Updated April 8, 2014. Accessed July 15, 2014.
Hemochromatosis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated June 24, 2014. Accessed July 15, 2014.
Iron deficiency anemia in adults. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated June 9, 2014. Accessed July 15, 2014.
- Reviewer: Michael Woods, MD
- Review Date: 07/2014 -
- Update Date: 07/15/2014 -