Anemia is a condition in which the body does not have enough healthy red blood cells. Iron helps make red blood cells.
When your body does not have enough iron, it will make fewer red blood cells or red blood cells that are too small. This is called iron deficiency anemia.
Anemia - iron deficiency
Causes, incidence, and risk factors
Iron deficiency anemia is the most common form of anemia.
Red blood cells bring oxygen to the body's tissues. Healthy red blood cells are made in your bone marrow. Red blood cells circulate through your body for 3 to 4 months. Parts of your body like your spleen remove old blood cells.
Iron is a key part of red blood cells. Without iron, the blood cannot carry oxygen effectively. Your body normally gets iron through your diet. It also reuses iron from old red blood cells.
You get iron deficiency anemia when your body's iron stores run low. This can occur because:
You lose more blood cells and iron than your body can replace
Your body does not do a good job of absorbing iron
Your body is able to absorb iron, but you are not eating enough foods that contain iron.
Your body needs more iron than normal (such as if you are pregnant or breastfeeding)
Bleeding can cause iron loss. Common causes of bleeding are:
Iron supplements (most often ferrous sulfate) are needed to build up the iron stores in your body. Most of the time, your doctor or nurse will measure your iron levels before starting supplements.
If you cannot take iron by mouth, you may need to take it through a vein (intravenous) or by an injection into the muscle.
Pregnant and breastfeeding women will need to take extra iron because they often cannot get enough iron from their normal diets.
Your hematocrit should return to normal after 2 months of iron therapy. You will need to keep taking iron for another 6 - 12 months to replace the body's iron stores in the bone marrow.
Iron-rich foods include:
Chicken and turkey
Dried lentils, peas, and beans
Meats (liver is the highest source)
Other sources include:
Raisins, prunes, and apricots
Spinach, kale, and other greens
With treatment, the outcome is likely to be good. However, it does depend on the cause.
Calling your health care provider
Call your health care provider if:
You have symptoms of iron deficiency
You notice blood in your stool
A well rounded diet should include enough iron. Red meat, liver, and egg yolks are high sources of iron. Flour, bread, and some cereals are fortified with iron. Take iron supplements if you aren't getting enough iron in your diet (uncommon in the United States).
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Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.