stage, the iron begins to affect the cells of the body's organs which manifests as numerous systemic signs and symptoms developing after 6 to 72 hours, in the metabolic acidosis phase. Individuals may present with signs of cardiogenic shock indicated by low blood pressure, rapid heart rate and severe shortness of breath. Hypovolemic shock occurs due to loss of blood from the gastrointestinal bleeding caused by the iron. During this phase, metabolic acidosis may also develop damaging internal organs such as the brain and liver. In the fourth stage taking place 12 to 96 hours after ingestion, liver toxicity and failure occurs as the cells begin to die. In the last stage of iron poisoning following 2 to 8 weeks after ingestion, scarring of the gastrointestinal mucosal lining resulting in bowel obstruction. Cause Pathophysiology Iron is essential for the production of hemoglobin in red blood cells which is responsible for transporting oxygen throughout the body. In normal physiologic conditions, nonionic forms of iron (Fe°) are converted into ferrous iron (Fe2+) by gastric acid in the stomach. Ferrous iron is then absorbed in the small intestine where it is oxidized into its ferric iron (Fe3+) form before being released into the bloodstream. Free iron in the blood is toxic to the body as it disrupts normal cell function, damaging organs such as the liver, stomach, and cardiovascular system. The human body has protective mechanisms in place to prevent excess free ferric iron from circulating the body. When being transported throughout the body, iron is bound to an iron transporting protein called transferrin to prevent iron from being absorbed into different cells. Any excess iron is stored as ferritin in the liver. In the event of iron overdose, iron stores become oversaturated and the body's protective mechanisms fail resulting in excess free circulating iron. Toxic Dose Iron poisoning can occur when doses of 20 to 60 mg/kg or more of elemental iron is ingested with most cases reporting primarily gastrointestinal symptoms. Systemic signs and symptoms shown in serious toxicity occur at higher doses exceeding 60 mg/kg. Ingesting above 120 mg/kg may be fatal. The therapeutic dose for iron deficiency anemia is 3–6 mg/kg/day. Individuals who have ingested less than 20 mg/kg of elemental iron typically do not exhibit symptoms. It is unlikely to get iron poisoning from diet alone with iron supplements being the cause of overdose. The amount of elemental iron