How much iron should I have in my body?
It depends. Adult women carry about 2 grams (g) of iron in their body, while adult men carry about 4 g.7 About 70% of this iron is found in red blood cells as heme in hemoglobin, 0.5 g to 1 g is stored, and the remainder is used in different parts of the cell. If we eat a well-balanced diet, our bodies do a very good job of absorbing and storing all the iron we need. Our bodies do not actively eliminate iron. However, people lose a small but steady amount of iron through their sweat and urine, and by shedding cells from the skin.8 Any time you lose blood (because of your period, due to an injury, etc.), you also lower your body's iron levels. The total amount of iron loss for healthy people is about 1 mg a day for men, and 1.5 mg to 2 mg a day for women with regular periods.7 Most of the iron in our bodies is stored and recycled by a system in the body that breaks down aged red blood cells.
As you get older, your body ends up storing more iron than it needs.9 In men, body iron stores rise sharply in the late teens, peak in their 30s, and stay level until age 70. After age 70, men's iron levels gradually decline. In contrast, women's levels remain low until about age 40, followed by a steep rise. The highest levels seen in women are still about one third lower than those in men.10
How do I know if my iron levels are too high or too low?
While you can have a blood test to measure the amount of iron in your blood, there is currently no way to measure all of the iron in your body. No single test can diagnose iron deficiency either. Instead, several tests are used to give an estimate of your iron level, each measuring a different iron storehouse in the body. These tests measure blood levels of iron, levels of ferritin, a protein that binds and stores iron, and transferrin a protein that transfers iron from the gut to the body parts that need it (this test is also called total iron binding capacity or TIBC). More than one test is usually needed to get the full picture of a person's iron levels.
| Understanding Iron Tests11, 12 | |||
|
|
Iron |
Transferrin |
Ferritin |
|
Normal Levels |
Men: 75 to 175 µg/dL |
200 to 400 mg/dL |
Men: 20 to 300 µg/L |
|
Disease |
|
|
|
|
Iron deficiency |
Low |
High |
Low |
|
Chronic illness* |
Low |
Low |
Normal-high |
|
High |
Low |
High |
|
|
Iron poisoning |
High |
Normal |
Normal |
|
*Chronic illness, such as diabetes or autoimmune disease, can disrupt the body's ability to use iron. ** Hemochromatosis is a genetic disease that causes a person's body to absorb too much iron. |
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