Iron is a mineral that’s needed by the body for many important functions, from growth and development to hormone balance and energy metabolism. One of its biggest and most well-known roles, however, is the part that plays in the production of hemoglobin. Hemoglobin is the part of red blood cells that makes it possible for oxygen to travel from the lungs to various tissues, such as skin and muscle, throughout the body. Iron also assists in bringing carbon dioxide back to the lungs so that it can be exhaled.
Iron is found naturally in many different foods; it’s also added to some fortified forms. Iron from animal sources, called heme iron, is more readily absorbed (about twice as much) than the type found in plants (non-heme iron). Varying sources of iron from both animal and plant sources can be helpful in preventing an iron deficiency.
Animal-based sources of iron (heme)
- Lean beef
- Turkey
- Chicken
- Lean pork
- Fish
Plant souces of iron (non-heme)
- Legumes – beans, soybeans and lentils
- Dark green leafy vegetables such as spinach or kale
- Fortified breakfast cereals
- Enriched rice or pasta
- Whole-grain and enriched breads
- Pumpkin seeds
- Dried fruits – apricots, raisins and prunes
Foods such as eggs, rice, some nuts or breads contain only 1 milligram of iron, and dairy products such as milk and cheese contain no iron at all, so keep that in mind when meal planning or addressing an iron deficiency.
Iron absorption
Because vitamin C can help the body absorb non-heme iron during digestion, complementing plant sources of iron with vitamin C foods can increase its absorption. Most chili recipes already combine beans and tomatoes for a perfect combination of non-heme iron and vitamin C for example, or consider adding sliced bell peppers on a kale and spinach salad for the same effect. Cooking foods in a cast iron skillet will add some iron to foods, too.
Iron needs throughout life
The body can actually recognize when more or less iron is needed and how much to absorb. While it’s pretty amazing how we can adapt, the recommended intake targets the general populations’ need.
The Recommended Dietary Allowances (RDAs) for iron in non-vegetarians in milligrams are as follows:
Age |
Male |
Female |
Pregnancy |
Lactation |
Birth to 6 months |
0.27 mg. |
0.27 mg. |
||
7–12 months |
11 mg. |
11 mg. |
||
1–3 years |
7 mg. |
7 mg. |
||
4–8 years |
10 mg. |
10 mg. |
||
9–13 years |
8 mg. |
8 mg. |
||
14–18 years |
11 mg. |
15 mg. |
27 mg. |
10 mg. |
19–50 years |
8 mg. |
18 mg. |
27 mg. |
9 mg. |
51+ years |
8 mg. |
8 mg. |
For the average adolescent and adult who eats meat, fortified food sources and a variety of plants, getting enough iron can be easy when planned appropriately. Breakfast cereal will typically contain 100 percent of the recommended daily value (up to 18 milligrams), while 6 ounces of cooked beef provides 4.2 milligrams of iron. One cup of cooked white beans has 8 milligrams, and ½ cup of cooked lentils or tofu serves up 3 milligrams of iron each.
Who is at risk for iron deficiency?
Even though iron is widely available in food, many people still don’t get the amount they need on a daily basis. If fact, iron deficiency is the most common nutritional deficiency and the leading cause of anemia in the United States.
Infants born premature or with a low birth weight: These infants may have reduced iron stores. An iron supplement will most likely be needed until the infant turns one year old. Formula is generally iron-fortified, so formula-fed babies don’t typically need an iron supplement. As infants begin to eat more solid food, around four o six months of age, dishing up iron-rich foods such as iron-fortified cereal, meat or beans a couple times a day will help meet their iron needs.
Infants and young children: Babies store enough iron for the first four to six months of life, but after that, iron needs increase. Iron deficiency anemia in infancy can lead to cognitive and psychological effects that can be detrimental, including delayed attention and social withdrawal. Try to avoid “milk anemia,” which can occur when kids drink too much milk that contains no iron and other foods don’t make it into the diet.
Adolescent girls: If an inconsistent or restricted diet is followed along with expected growth spurts, adolescent girls can be at risk for iron deficiency. Fatigue, shortness of breath, frequent colds or feeling sick, headaches and brittle fingernails are common signs to look for. Growth during this stage of life demands more iron to support building muscle mass and an increase in blood volume.
Women of childbearing age: Menorrhagia, or abnormally heavy bleeding during monthly periods, can increase a woman’s risk of iron deficiency. At least 10 percent of menstruating women are believed to have menorrhagia.
Women who are pregnant or breastfeeding: Maternal iron deficiency is the most common nutritional deficiency during pregnancy. Increased blood volume requires more iron (27 milligrams of iron daily) to deliver oxygen to the baby. Be sure to talk to your doctor about taking a prenatal vitamin that contains iron.
Vegetarians or vegans: The daily recommendation for vegetarians and vegans is 1.8 times higher than meat-eaters. Legumes, whole and enriched grains and some vegetables and dried fruits are especially rich in iron and are frequently eaten foods on vegetarian or vegan meal plans. In fact, vegan diets often are higher in iron than omnivore diets, the non-heme iron just needs to be eaten with a vitamin C source in the same meal or snack. Just ½ cup cooked broccoli contains 50 milligrams of vitamin C which can significantly increase the absorption of non-heme iron.
Endurance athletes: Knowing that iron is essential for energy metabolism, this is a key nutrient for endurance athletes. If red meat is limited in an endurance runner’s diet, chicken and fish, such as salmon, snapper and perch, should be cooked in a cast iron skillet to increase iron intake in addition to eating a variety of plant-based sources of iron on a daily basis.
Frequent blood donors: In the United States, adults may donate blood as often as every eigh weeks, which can deplete iron stores. About 25 percent to 35 percent of regular blood donors develop iron deficiency.
People with cancer: Anemia of chronic disease and chemotherapy-induced anemia are the most common reasons for people with cancer to develop anemia. Chronic blood loss and deficiencies of other nutrients can bring about iron deficiency in this population.
People who have gastrointestinal disorders or have had gastrointestinal operations: People with certain gastrointestinal disorders like celiac disease, ulcerative colitis and Crohn’s disease or have had certain gastrointestinal surgeries may become iron deficient because of dietary restrictions, the inability to absorb iron correctly or blood loss in the gastrointestinal tract caused by the condition or surgery.
People with heart failure: About 60 percent of patients with chronic heart failure have iron deficiency and 17 percent have iron deficiency anemia. If iron cannot be absorbed properly or the diet is lacking in general nutrients, or if aspirin is being taken regularly, iron deficiency can occur.
When to ask your healthcare provider about iron supplements
If you fall into any of the groups that are at risk for an iron deficiency and/or exhibit any of the common symptoms, the next step is to visit your healthcare provider. A simple finger prick test or having blood drawn at a lab can determine iron deficiency or anemia.
Symptoms of iron deficiency anemia can include:
- Fatigue
- Pale skin and fingernails
- Weakness
- Dizziness
- Headache
- Glossitis (inflamed tongue)
Iron supplements are available online from trusted sources or over the counter in most drug or grocery stores. Iron supplements are available in both ferrous and ferric forms, with the former being more bioavailable than the latter. If these forms cause GI-upset, your healthcare provider can recommend other forms. Taking an iron supplement to address iron deficiency or anemia should always be done under your doctor’s supervision as high doses of iron can be dangerous.
Avoiding iron deficiency
Eating a well-balanced, healthy diet that includes a variety of foods from all five food groups, especially fruits and vegetables, can help ensure enough of both heme and non-heme iron are making onto the plate.
If you have concerns about getting enough iron in your diet, speak with a registered dietitian with The Little Clinic (available in select Kroger/King Soopers locations) to learn more about meal planning with iron in mind.