Too Much Iron: Iron Overdose

In depth research on essential vitamins.


Too Much Iron: Iron Overdose
By: Dr. George Obikoya

Why do you need Iron? Iron is a mineral that functions primarily as a carrier of oxygen in the body, both as a part of hemoglobin in the blood and of myoglobin in the muscles. The body increases or decreases iron absorption according to need. The presence of vitamin C (ascorbic acid) in a meal increases iron absorption. The body absorbs iron more efficiently when iron stores are low, and during growth spurts or pregnancy.

The most common indication of poor iron status is iron deficiency anemia, a condition in which the size and number of red blood cells are reduced. This condition may result from inadequate intake of iron or from blood loss.
When there is insufficient iron from dietary sources, or as a result of blood loss in the body, the amount of hemoglobin in the bloodstream is reduced and oxygen cannot be efficiently transported to tissues and organs throughout the body. Iron-deficiency anemia is characterized by fatigue, shortness of breath, pale skin, concentration problems, dizziness, a weakened immune system, and energy loss.

Inadequate intake or iron can cause ill-health but just as important as a cause of illness is consuming too much of Iron. Indeed, Iron excess is a greater risk than iron deficiency for many older Americans. In a study of more than 1,000 white men and women aged 67 to 96 who live at home, 13 percent had too much iron in their blood, but only three percent had too little.

Healthy people usually absorb about 10 percent of the iron contained in the food they eat to meet the body needs. This is why we need to take iron supplements. But wait a minute. We need to get a few things clear. Let's define anemia: a deficiency of red cells or hemoglobin, or red cells that die too young or are discolored or possess an abnormal shape, or red cells that lack adequate iron. Now defining iron deficiency vary from lab to lab. Most "normal" levels are set too high. Saturation: 12 to 40-45% is reasonable at the present time. Ferritin: 5 to probably 50. Think about it. If "normal" levels are set artificially high, and your levels fall below that "normal," you are "iron deficient."

So how much iron do you really need? Iron is not excreted. The iron you absorb stays and accumulates in storage except that you can lose one milligram a day through hair, finger nails, skin cells and other detritus. That is the amount needed every day to replace the loss. One milligram, that's all and for women in reproductive years, one and a half milligram. The other way to lose iron, of course, is by blood loss.

The other thing to note is that hemoglobin is not iron! Yes, you are anemic if your hemoglobin is low but that does not necessarily mean your iron is low. Indeed, what might be happening is that the iron is collecting in storage instead of going into hemoglobin. You are actually iron-loaded and need iron removed despite the anemia. The anemia should be treated with B vitamins, especially B12, B6 and folic acid. Many patients with anemia are dying of iron overload, and some are hastened to their death by their physicians who give them more iron.

Even a small amount of excess iron can damage heart and brain and other storage sites in the body and lead to heart attack or stroke. There is exaggerated concern when hemoglobin falls temporarily, following surgery, for example. Blood transfusions are over-used. A study shows that surgery patients who do not receive transfusions survive better than those who do.1

Before taking iron you must test saturation and ferritin. Ferritin indicates storage iron, which is not essential to maintain life. If both saturation and ferritin are extremely low, you must find out why. Low iron is a signal that iron is being used by cancer cells or is feeding bacteria, or usually it means there is chronic daily blood loss. The bleeding could be from an ulcer or tumor, etc. The source must be found.

Iron is in just about everything. If you are not absorbing the one daily milligram, you are truly on a starvation diet, and low iron is the least of your worries. So, go for iron supplementation only when you need it and be aware of iron's toxic ability to harm you.

Severe iron overload, which causes liver and heart damage, can occur in people who are genetically susceptible. This is called haemochromatosis. Haemochromatosis, also called iron storage disease, or bronze diabetes is an inborn metabolic defect characterized by an increased absorption of iron, which accumulates in body tissues. The body has no natural way to rid itself of excess iron, so extra iron is stored in body tissues, especially the liver, heart, and pancreas.

People with haemochromatosis absorb more than the body needs The clinical manifestations include skin pigmentation, diabetes, enlargement of the spleen and liver, heart failure, and general weakness and lassitude. In males, the symptoms are usually noted after 35 years of age, and in females, after menopause, when iron is no longer lost through menstruation and pregnancy. Treatment consists of the removal of blood at regular intervals to decrease the concentration of body iron.

Excess stored iron can lead to atherosclerosis and ischemic heart disease. Phlebotomy, or blood removal, has been used to reduce stored iron in patients with iron overload with some success. Iron chelation with drugs such as desferrioxamine (Desferal) that help patients excrete excess stores of iron can be helpful in treating iron overload caused by multiple blood transfusions.

Men and postmenopausal women don't need the 18 milligrams of iron in most multivitamin/mineral supplements. Unless your doctor says you're low in iron, look for a brand with zero milligrams.

A good multivitamin is the foundation of health and nutrition. Take a look at our scientific reviews of many of the popular brands for factors such as ingredients, areas of improvement, quality level, and overall value. If you are looking for a high quality liquid multivitamin, we suggest that you take a look at the Multivitamin Product Comparisons.


1. NEJM Feb 1999 340:409-17

2. American Journal of Clinical Nutrition 73: 503, 638, 2001.

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