About 65% of iron is in the form of hemoglobin with small amounts found in the myoglobin of muscle, the cytochromes and iron containing enzymes.
The function of red blood cells, facilitated by the iron-containing hemoglobin molecule is to transport oxygen from the lungs to the tissues.
The rate at which hemoglobin is synthesized depends on the availability of iron for heme synthesis. A lack of iron results in relatively small amounts of hemoglobin in the red blood cells. When this happens, the oxygen carrying capacity of the blood is decreased and the individual will develop symptoms of anemia, such as fatique and pallor.
When red blood cells age and are destroyed in the spleen, the iron from their hemoglobin is released into the circulation and return to the bone marrow for incorporation into new red blood cells or to the liver and other tissue for storage.
Iron in hemoglobin
