What does iron do?
Iron is an essential mineral that’s a component of hundreds of proteins and enzymes in your body. Most of your iron is found in hemoglobin, a protein in your red blood cells that transports oxygen from your lungs to all of your cells. The mineral is also a component of myoglobin, a protein in your muscle tissue that stores oxygen. A quarter of your body’s iron is stored for later use, mainly in your liver, spleen and bone marrow.
Your immune system needs iron to create T cells and compounds that ward off infections, and the mineral also appears to help us stay sharp—people who get enough of it perform cognitive tasks faster and with better accuracy than those who are deficient in it.
How much iron do you need?
The recommended dietary allowance of iron for adults ranges and depends on your age and gender. Pregnant women need more than usual, in part to support their developing fetus and the placenta, while women who are breastfeeding need less. The recommendations are:
- 8 mg for men age 19 and older and women age 51 and older
- 18 mg for women ages 19 to 50
- 27 mg for women who are pregnant
- 9 mg for breastfeeding women ages 19 to 50
Your doctor may recommend that you get even more iron if you have certain health concerns, like iron-deficiency anemia, celiac disease or another gastrointestinal condition that affects iron absorption, very heavy periods or uterine bleeding related to hormone replacement therapy. You’ll also have higher iron requirements if you practice a vegetarian or vegan lifestyle or do regular, intense exercise (like intense endurance training), so talk to your doctor or a nutritionist about the right amount for you.
If you don’t get enough of the mineral, you may feel low on energy, weak and grumpy. You might also experience headaches and notice a decline in mental sharpness. Your symptoms will be more serious if you develop anemia. Blood tests and other exams can determine if you’re iron deficient. If so, you’ll need to focus on eating iron-rich foods, and your doctor or nutritionist may recommend that you take supplements for up to a year to restore your body’s iron supplies. If you’re still very low in iron after this, you’ll likely be given tests, such as a colonoscopy or endoscopy, to figure out what’s causing the prolonged deficiency.
Where can you get iron?
Iron from animal sources (heme iron) is more readily absorbed by our bodies than iron from plant sources (non-heme iron). Both vitamin C and heme iron improve the absorption of non-heme iron, so it’s a good idea to combine foods that contain these nutrients.
Some of our favorite foods that contain predominately heme iron:
Some of our favorite foods that contain non-heme iron:
|Food||Serving Size||Iron (mg)|
|Fortified instant oatmeal||1 cup||10.0|
|Millet||1 cup, cooked||5.8|
|Lima or kidney beans||1 cup, cooked||4.5|
|Pumpkin seeds||1 oz||4.2|
|Black or pinto beans||1 cup, cooked||3.6|
|Blackstrap molasses||1 Tbsp||3.5|
|Soybean nuts||½ cup||3.5|
|Spinach||1 cup, cooked||3.2|
|Sunflower seeds||½ cup||2.7|
You can look up the iron content of other foods by referencing the USDA National Nutrient Database for Standard Reference.
If you’re not getting enough iron from food, supplements are another option. (Vegetarians and vegans, especially, may need supplements.) Iron supplements should be taken separate from other mineral supplements because they will compete for absorption into your body. Some forms of iron supplements may cause constipation; we recommend chelated iron because it’s the most gentle to your gastrointestinal tract.
Keep in mind that too much iron in the body can cause problems, including gastrointestinal troubles. An excess of iron is also associated with oxidative stress and cellular damage, and may increase the risk of cardiovascular disease and cancer.