Iron poisoning is caused by an excess of iron in the blood. It is relatively common in young children who consume large quantities of iron supplement pills, which resemble sweets and are widely used, particularly by pregnant women. It may also be caused by consuming tap water or (less commonly) moonshine.
In nature, iron is usually found in its oxidized form, iron (III) oxide, which is insoluble and therefore non-toxic. Ferrous iron is soluble and highly toxic.
The first indication of iron poisoning by ingestion is a pain in the stomach, as the stomach lining becomes ulcerated. This is accompanied by nausea and vomiting. The pain then abates for 24 hours as the iron passes deeper into the body and damages internal organs, particularly the brain and the liver, and metabolic acidosis develops. The body goes into shock and death from liver failure can result.