Hemochromatosis is a disease believed to be due to an inborn error of metabolism in which excessive iron is absorbed from the diet. The danger of excessive ingestion of medicinal iron is constantly present, especially as enthusiastic advertising leads the health-conscious layman to believe that iron is a body strengthener and a tonic. This may result in persons believing that the more that is taken the better for his or her health. Accidental poisoning with ferrous sulfate has sometimes been fatal in children. In iron overload, the plasma iron content is high, the iron binding capacity is depressed and the percent saturation is nearly complete.
Iron overload is unknown from iron fortification of foods.
There is new evidence that suggests that an over-consumption of iron could lead to increased heart attack risk. Vitamin B6 is necessary for the formation of hemoglobin, the iron-containing protein in red blood cells. Iron competes with calcium, manganese, and zinc for absorption in the intestine and excess intake of one of these minerals could produce a deficiency of the others. The tannins that occur in the bark and fruit of many plants bind with iron to form insoluble iron salts that are not absorbable by the body. This includes tea and coffee.