Overdosed on Iron

When it comes to the iron in your diet, too much of a good thing can hurt you. Folks with a genetic condition called hemochromatosis absorb so much iron from their food that their body literally starts to rust from the inside out. More than 1 million Americans suffer from the disorder, although most of them don't know what they've got. Part of the reason is that hemochromatosis can masquerade as other diseases, like diabetes and arthritis. In addition, according to a series of articles in last week's Annals of Internal Medicine, most doctors still don't realize how common the disorder is.

Most of us absorb only 10% to 15% of the iron in our food. But people with hemochromatosis soak up 75% or more. The body stores the excess wherever it can--in the liver, heart, pancreas, joints--where it eventually causes permanent tissue damage. But the changes can be subtle. For example, iron buildup in the pituitary gland, which controls hormone production in the brain, may trigger impotence in men and early menopause in women. People of Scottish, Irish and Welsh backgrounds appear to be affected more than others--possibly because their ancestors ate a diet deficient in iron. There have also been reports of greater incidence among Hispanics and South African blacks.

The best way to get rid of excess iron is through periodic bloodletting. That usually means giving up a pint every week or two for a year, and then once every few months or so. (Unfortunately, most blood banks won't accept the donation, more as a precaution than anything else.) Menstruation may help some women, but it doesn't protect them entirely.

So how do you know if you have hemochromatosis? Doctors use three blood tests to measure the amount of iron in the body. Anyone taking the tests should avoid iron supplements, including multivitamins, for at least a week beforehand. Even then, doctors don't always recognize the disorder. "I just had a patient in my office who was known to have a 100% iron-saturation level for years," but his physicians didn't do anything about it, says Dr. Geoffrey Block, director of the Hemochromatosis Clinic at the University of Pittsburgh Medical Center. "There's still a perception that if the iron levels aren't low, you don't need to worry."

Some doctors believe everyone should be tested for hemochromatosis. But that could be a problem, since the tests aren't foolproof. At the very least, anyone with a family member who has hemochromatosis should get tested. In addition, if you have arthritis, diabetes or cardiac arrhythmia, your doctor should make sure that the difficulty isn't actually a result of iron overload.

Can you develop hemochromatosis simply by taking iron supplements? No. As a general rule, taking an iron pill is a problem only for folks with a hereditary predisposition to hemochromatosis. However, it is possible to ingest too much iron no matter what your genetic background. An overdose of just a few dozen iron pills can make adults very sick and is enough to kill toddlers. So keep your supplements out of kids' reach. And if you suspect iron poisoning, call your local poison-control center or head for the emergency room.

For information and Web resources, visit hemochromatosis.org or americanhs.org You can e-mail Christine at gorman@time.com