BS iron is an important component of hemoglobin, the substance in red blood cells that carries oxygen from your lungs to transport it throughout your body. Hemoglobin represents about two-thirds of the body’s iron. If you don’t have enough iron, your body can’t make enough healthy oxygen-carrying red blood cells, also has a role in a variety of other important processes in the body. A shortage of iron in the blood can lead to a range of serious health problems, including iron deficiency (anemia).