Iron toxicity is less common than deficiency and is usually due to a genetic disorder called hemochromatosis, or iron storage disease. If you have this condition, your body stores excessive amounts of iron that can lead to organ damage, especially to the heart and liver. If you have hemochromatosis, your doctor may have told you to reduce your intake of dietary iron.
Women who still have menstrual periods need about 18 milligrams of iron each day. Men and post-menopausal women need less, about eight milligrams. Pregnant women need 27 milligrams per day.
Dietary iron is found in both plant and animal-based foods, but the structure differs. Plant-based iron is called non-heme iron and it isn't as easily absorbed as the animal-based heme iron. Most of the iron in fortified and enriched foods is non-heme iron.
Foods High in Non-Heme Iron
- Iron-fortified breakfast cereals (hot or cold): one cup has up to 18 milligrams
- Soybeans: one cup has 8.8 milligrams
- Lentils: one cup has 6.6 milligrams
- Dry beans (kidney, lima, navy, black beans): one cup has up to 5.2 milligrams
- Blackeyed peas: one cup has 4.3 milligrams
- Tofu: one-half cup has 3.4 milligrams
- Spinach: one-half cup cooked spinach has 3.2 milligrams
- Raisins: one-half cup has 1.6 milligrams
- Grits: one cup has 1.5 milligrams
Foods High in Heme Iron
- Chicken liver: a 3-ounce serving has 11 milligrams
- Oysters: a 3-ounce serving has 5.7 milligrams
- Beef liver: a 3-ounce serving has 5.2 milligrams
- Beef chuck roast: a 3-ounce serving has 3.1 milligrams
- Beef (ground or steak): a 3-ounce serving has up to 2.2 milligrams
- Light tuna: a 3-ounce serving has 1.3 milligrams
- Turkey breast: a 3-ounce serving has 1.1 milligrams
- Chicken: a 3-ounce serving has up to 1.1 milligrams
Normally, your body absorbs more iron when your iron stores are low, and less when your iron stores are high. Non-heme iron isn't absorbed as well as heme iron, and absorption is generally reduced by the presence of calcium, polyphenols, tannins found in tea and red wine, phytates found in legumes and grains, and certain soy proteins. You can increase absorption of non-heme iron by eating foods rich in vitamin C or meat proteins along with your plant-based iron sources.
Iron supplements are commercially available, but you should speak with your healthcare provider before taking iron or any other dietary supplements. Taking an excess of iron supplements can cause toxicity, so follow the dosage recommendations found in the product directions unless your healthcare provider has told you to take a different dose. Keep iron supplements out of the reach of children.
Academy of Nutrition and Dietetics. "Can You Have Too Much Iron in Your Blood?" Accessed May 7, 2012. http://www.eatright.org/Public/content.aspx
Institutes of Medicine. "Dietary Reference Intakes: Minerals." Accessed May 7, 2012. http://iom.edu/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Elements.pdf
National Institutes of Health, Office of Dietary Supplements. "Dietary Supplement Fact Sheet: Iron." Accessed May 7, 2012. http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/