Deficiency and toxicity: There is a controversy about iron toxicity-is everyone sensitive to iron overload from supplements, or does it affect only people who are genetically predisposed to iron accumulation and irritation? Iron overload is seen most commonly in older men because they tend to take supplements or iron tonics though losses may be small and through the years tend to accumulate iron stores, primarily in the liver. Usually, it takes moderately high amounts over a long period with minimal losses of this mineral to develop any iron toxicity problems. Further research by Jerome Sullivan suggests that iron overload is a factor in the development of atherosclerosis. A high-meat diet, separate iron supplements, or even the extra 18 mg. of iron that is contained in the average RDA-type multivitamin is more than many people, particularly men, require. Men lose very little iron, since the body recycles most of it; their needs are only about 10 mg. daily. Consuming much more than this may increase the risk of atherosclerosis and heart disease by an as-yet-undetermined mechanism, possibly through increased oxidation and free-radical formation. Women in the menstruating years seem to be protected from this increased risk, though they lose this protection after menopause, when their risk of heart disease rises to a level close to men's.

Children have been known to develop acute toxicity from eating extra vitamins or finding some of mother's ferrous sulfate or other iron supplement. Each year there are about ten deaths reported of young children who eat more than ten 300 mg. iron tablets-that is, more than 3 grams of iron-at one time.

It is unlikely that one would develop any iron toxicity from dietary sources alone, even with 50-75 mg. per day intake, unless all food is prepared in iron cookware, as is done in some African tribes, or unless the genetic iron storage disease called hemochromatosis is present. If this disease occurs, tissue damage may result from iron deposits in the liver, pancreas, spleen, skin, or heart. These iron deposits can cause cirrhosis of the liver, fibrosis of other tissues, a bronze color to the skin, and diabetes due to pancreatic disease, as well as joint problems or cardiac insufficiency. Hemochromatosis, a genetic metabolism problem that probably affects the regulation of iron absorption, can be discovered through blood tests and occurs in about 1 person in 20,000. Treatment includes a low-iron diet, avoidance of iron supplements, and giving regular donations of blood so that the iron stores will be used to make new red blood cells.

The term for excess iron storage in the body is hemosiderosis, or siderosis. Here an amorphous brown pigment called hemosiderin (about 35 percent iron as ferric hydroxide) is deposited in the liver and other tissues, which is not usually a problem unless there are excessive amounts. These increased iron stores usually come not from diet but from iron supplements or blood transfusions. Symptoms of iron toxicity include fatigue, anorexia, weight loss, headaches, dizziness, nausea, vomiting, shortness of breath, and a grayish hue to the skin. Iron has been found in increased levels in joints of patients with rheumatoid arthritis and may contribute to inflammation through increased hydroxyl free radicals. Supplementation should be avoided by patients with arthritis unless a proven iron deficiency is present.

Our digestion does not really screen excess iron, and our elimination is low after we absorb it. Therefore, it is fairly easy to get iron overloads in the body, although it is much easier to develop an iron deficiency.