In the 2005 edition of "Modern Nutrition in Health and Disease," U.S. Department of Agriculture scientist Richard J. Wood, Ph.D. explains that all living organisms, including humans, require iron. Although iron is abundant on Earth, Wood says most of the Earth's iron exists as metal or iron oxide that is not biologically useful. As a result, most humans struggle to meet their iron needs. Some succeed more than others and the result, in rare cases, is excess iron levels.
Causes
Excess iron levels occasionally result from chronic ingestion of unnecessary iron supplements. More often, however, excess iron levels result from hereditary diseases. Hereditary hemochromatosis --- one of most common genetic diseases in the United States, according to MedlinePlus --- causes affected individuals to absorb more iron than normal from the diet. Excess iron levels associated with other hereditary diseases, such as thalassemia, sickle cell disease and X-linked sideroblastic anemia, result from repeated blood transfusions.
Symptoms
Symptoms of excess iron levels include chronic fatigue, joint pain, abdominal pain, irregular heart beat, irregular or absent menstrual periods, impotence, infertility, decreased libido, depression, hair loss and bronze or ashy-green skin tone. Over time, patients may develop liver disease, such as cirrhosis or cancer; heart attack or heart failure; osteoarthritis; osteoporosis; diabetes; or early onset or exacerbation of neurodegenerative diseases, such as Parkinson's disease, Huntington's disease, Alzheimer's disease, epilepsy and multiple sclerosis.
Diagnosis
Your doctor may suspect excess iron levels on the basis of your history or physical examination. Sometimes they are discovered incidentally by blood tests for another problem or during a procedure. Iron levels vary by age and gender. Normal hemoglobin for an adult female is 12 to 16 mg per deciliter, or dL, compared to 13 to 18 for an adult male. Normal ferritin, a storage form of iron, is 10 to 200 micrograms, or mcg, per L for a woman and 15 to 400 for a man. Normal serum iron is 50 to 150 mcg per dL for adults of both genders. Your doctor may also order an MRI to assess for excess iron levels in tissues outside the blood, such as the heart, liver, pancreas, brain and joints.
Treatment
For hereditary hemochromatosis and excess iron levels due to supplement ingestion, your doctor may recommend that you donate blood. Each pint of blood withdraws 250 mg of iron. For other causes of excess iron levels, you may require prescription drugs called iron chelators. These bind stored iron in the blood and cause it to be excreted in urine, which usually acquires a black or green tint. Your doctor may also recommend that you follow a reduced-iron diet or that you take steps, such as drinking tea, that reduce the amount of iron you absorb from food.
Prevention
Excess iron levels cause permanent organ damage that cannot be detected until it has already occurred. If you have a hereditary disorder that causes excess iron levels, your doctor may recommend that you begin donating blood, taking iron chelators and consuming a reduced iron level soon after you are born. Complying with these recommendations may help you avoid permanent organ damage. You can also reduce your risk of excess iron levels by taking iron supplements only when your doctor tells you to do so.
References
- "Modern Nutrition in Health and Disease, 10th Edition"; Maurice E. Shils, M.D., D.Sc. et al.; 2005
- Iron Disorders Institute: Iron Overload
- MedlinePlus: Hemochromatosis
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