Iron is a mineral found mostly in red blood cells, also known as erythrocytes. These are the most common blood cells in the bloodstream. Blood also contains white cells, or leukocytes, which are part of the immune system, platelets involved in healing, and a variety of proteins. Some of these proteins, such as transferrin and ferritin carry iron. Certain conditions are associated with high levels of iron and hemoglobin. A health care practitioner should be consulted regarding diagnosis and management of disease.
Iron in the Body
Iron binds to oxygen in red blood cells to transport the oxygen from the lungs to the rest of the body. It also helps cells to grow and perform specific functions. Iron is found in meats, fortified cereals, beans and some vegetables. After iron is absorbed in the GI tract, it is moved from one place to another by the protein transferrin, and stored by the protein ferritin according to "Pathologic Basis of Disease" by Dr. Vinay Kumar. High iron levels from dietary or supplementation are more likely in men, and women after menopause because they do not lose iron in blood.
Hemoglobin in the Body.
Hemoglobin is a protein inside red blood cells that carries about two-thirds of the iron in the body. It is synthesized in the red blood cells during their development in the bone marrow. The red cells along with their hemoglobin leave the bone marrow and enter the blood. When they reach the lungs, oxygen enters the red cells and binds to the iron atoms bound to hemoglobin. Levels of hemoglobin vary with disorders affecting red blood cells.
Diseases of Iron Overload
According to "Harrison's Principles of Medicine" by Anthony Fauci, M.D., iron overload is generally from either multiple, ongoing blood transfusions or the disease hemochromatosis, although other causes such as excessive supplements can also be a cause. Multiple blood transfusions are most common in people with hereditary anemias. Hemochromatosis is from a genetic change that causes the body to absorb too much iron and not break it down. It largely damages the heart, pancreas and liver.
Diseases with High Hemoglobin
High hemoglobin can be a normal response to some conditions such as living at high altitude where less oxygen is available. It can also be a response to other conditions such as heart or lung disease. Additionally, it can be a disorder of bone marrow. In polycythemia vera, the bone marrow makes too many red blood cells. Iron and hemoglobin counts will both be high from the excessive red cell production.
- “Robbins and Cotran Pathologic Basis of Disease”; Vinay Kumar et al; 8th Ed 2009
- National Institutes of Health: Office of Dietary Supplements: Dietary Supplement Fact Sheet: Iron
- “Harrison’s Principles of Internal Medicine”; Anthony S Fauci et al; 17th Ed 2008