Like many other micronutrients, iron is an important mineral that the human body cannot produce it. We get all of our iron from the food that we eat. One of the most important functions of iron is that it is used to produce hemoglobin. This is the part of the red blood cell that carries gases like oxygen throughout the bloodstream. Red blood cell production is an ongoing process throughout life. Therefore iron is always needed.
Excess Iron in the Body
Too little iron can affect red blood cell function. We refer to this as anemia and more specifically as iron deficiency anemia. However, too much of iron in the body can also have negative consequences. Excessive amounts of iron can accumulate in different tissues in the body and even lead to organ damage over time.
The body can handle sudden iron overload in the short term. However, when the excessive iron administration is ongoing then iron will accumulate in different organs. This iron accumulation in the organs does not immediately damage organ tissue. Even in this case the body will remove the excess iron through various mechanisms. However, the body will eventually not cope with this chronic iron overload and tissue damage will occur.
Hemosiderosis and Hemochromatosis
Hemosiderosis is where a storage form of iron known as hemosiderin accumulates in the tissue spaces. This usually does not cause tissue damage. Hemochromatosis is where a chronic iron overload causes iron to accumulate in body tissues and results in tissue damage. There are two types of hemochromatosis – primary and secondary.
Primary and Secondary Hemochromatosis
Primary hemochromatosis occurs on its own and not due to any other disease. This is a result of a gene defect which causes the body to absorb large amounts of iron from food. It is a very common genetic disorder but many people who have this condition do not have an symptoms. They are therefore not aware that they have primary hemochromatosis.
Secondary hemochromatosis occurs due to another disease or condition which affects the iron levels in the body. This may be seen with chronic liver disease, frequent blood transfusions and kidney dialysis. It can also occur with certain types of anemia where the body does not use the iron to produce red blood cells. This unused iron can the accumulate in various body tissues.
Causes of Iron Overload
Any excess iron within the body is a result of iron not being utilized or stored properly, or absorbed in excess from food in the gut. Some of these causes may be due to genetic disorders or diseases but even dietary factors can contribute to excess iron in the body.
Iron supplements where iron exists as ferrous sulphate or ferrous gluconate, multivitamins with iron and carbonyl iron (an iron plus carbon monoxide combination) can cause iron overload if used excessively (iron poisoning).
Long term intake of excessive iron supplements will result in hemosiderosis (iron overload) which may then be followed by hemochromatosis (iron toxicity). Iron poisoning is one of the most common types of poisoning in children which may lead to death.
- Genetic disorders, such as primary hemachromatosis, atransferrinemia and thalassemia major.
- Increased iron intake apart from iron ingestion.
- Repeated blood transfusions.
- Kashin-Beck disease
- Excess intake of vitamin C may be linked to iron overload but is more likely to occur in the backdrop of primary hemochromatosis.
Signs and Symptoms
Acute iron poisoning causes a number of gastrointestinal and systemic signs and symptoms which may also be present in hemosiderosis and hemochromatosis.
- Upper abdominal pain
- Paleness of the skin (pallor) or even a bluish tinge (cyanosis)
Other signs and symptoms associated with chronic iron overload (hemosiderosis) or iron toxicty (hemochromatosis) include :
- Chronic abdominal pain
- Abnormal skin pigmentation, usually yellow to bronze.
- Liver cirrhosis
- Cardiac disorders including cardiomegaly (‘enlarged heart’), arrhythmias or even cardiac failure.
- Loss of libido
- Shrinking of the testes (atrophy)
Diagnosis of Excessive Iron in the Body
The presence of the signs and symptoms of iron poisoning is not a reliable way to diagnose the condition. These symptoms can occur with various other diseases and disorders. Furthermore most people with iron overload have little to no signs and symptoms. Therefore diagnostic investigations are necessary.
The main blood tests are to confirm the presence of high iron levels in the blood (serum transferrin saturation) and high iron in the liver (serum ferritin). A sample of the liver tissue may also be taken (biopsy) and examined for iron deposition. These investigations are usually sufficient to confirm iron overload.
Treatment of Iron Toxicity
Treatment for iron toxicity is not always necessary. If it is acute then the body will remove the excess iron through various mechanisms. Iron supplementation should be stopped. However, treatment may be necessary in chronic cases where the cause of the iron overload cannot be removed.
The two options for the treatment of iron overload are phlebotomy and chelation. If there are other signs and symptoms due to the complications of iron overload then it should also be treated.
Phlebotomy is the removal of blood from the body. It is also known as blood letting and must be done by a medical professional. This may need to be done on a regular schedule. Chelation therapy is an option for people who cannot have their blood removed. This involves administering certain medication which will bind with iron and then the body can expel it.
How to Prevent Iron Overload?
Depending on the cause, certain preventative measures may be necessary to avoid iron overload in the future. It is important to first discuss preventative measures with a medical professional. These ways to prevent iron overload includes:
- Discontinuing all iron supplements. This includes supplements that may contain small quantities of iron, like multivitamin supplements.
- Reduce vitamin C supplements. It is not essential to avoid foods containing vitamin C but supplements should be stopped.
- Limit or avoid alcohol intake. Alcohol can worsen liver damage and impair its function further which can affect iron utilization and removal from the body.