Iron Toxicity: The Dark Side Of Taking Too Many Iron Supplements

by Dr. Jonathan D'Souza

An essential dietary mineral used by red blood cells, iron forms a crucial part of hemoglobin, a protein which helps carry oxygen to all the cells of our body.

High iron levels increase the secretion of hepcidin—the hormone that regulates iron levels in the body—which decreases iron absorption. Alternately, when the body has low iron levels, the secretion of hepcidin is reduced, resulting in increased iron absorption.[1]

An excessive use of iron supplements is the most likely cause of an overdose of iron and can cause severe iron poisoning.

What Is Iron Toxicity?
Iron toxicity results from excessively high levels of iron in the body. It can be sudden or gradual and can lead to serious health problems caused by chronic iron overload disorders, accidental overdoses or taking high-dose supplements for a long time.

Normally, free iron circulated in the bloodstream binds to proteins (called transferrin) that make it harmless. However, high levels of iron increase the free iron in the blood, which then becomes a pro-oxidant (the opposite of antioxidant) and can damage the cells.

Causes Of Iron Toxicity
1. African Iron Overload: This is a type of dietary iron overload, which was first seen in Africa where homemade beer was brewed in iron vessels. It is caused by the high levels of irons in drinks and foods.[2]

2. Hereditary Hemochromatosis: A genetic disorder in which excessive absorption of iron from food takes place.[3]

3. Iron poisoning: This can result when people (usually children) take an overdose of iron supplements.[4,5]

Health Problems Due To Iron Toxicity

  • Animal and clinical studies show that iron overload may lead to cancer.[6,7]
  • Clinical studies have shown that heme iron from supplements or red meat could increase the formation of cancer-causing N-nitroso compounds in the digestive tract.[8,9]
  • Excessive levels of iron in the blood can also stimulate the growth of bacteria and viruses causing infection.[10]

How To Minimize Iron Toxicity?
If you are genetically prone to increased iron absorption or have taken an excess of iron supplements, you can minimize your health risks by following these tips.

  1. Avoid using iron cookware.
  2. Do not take vitamin C supplements with foods that are rich in iron as it increases iron absorption in the body.
  3. Donate blood once in every three months.
  4. Reduce your intake of iron-rich foods such as red meat.
  5. Never take iron supplements unless recommended by your doctor.

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1. Steinbicker AU, Muckenthaler MU. Out of balance–systemic iron homeostasis in iron-related disorders. Nutrients. 2013 Aug 2;5(8):3034-61. doi: 10.3390/nu5083034. Review. PubMed PMID: 23917168; PubMed Central PMCID: PMC3775241.

2. Gordeuk VR. African iron overload. Semin Hematol. 2002 Oct;39(4):263-9. Review. PubMed PMID: 12382201.

3. Pietrangelo A. Hereditary hemochromatosis: pathogenesis, diagnosis, and treatment. Gastroenterology. 2010 Aug;139(2):393-408, 408.e1-2. doi: 10.1053/j.gastro.2010.06.013. Epub 2010 Jun 11. Review. PubMed PMID: 20542038.

4. Chang TP, Rangan C. Iron poisoning: a literature-based review of epidemiology, diagnosis, and management. Pediatr Emerg Care. 2011 Oct;27(10):978-85. doi: 10.1097/PEC.0b013e3182302604. Review. PubMed PMID: 21975503.

5. Reynolds LG, Klein M. Iron poisoning–a preventable hazard of childhood. S Afr Med J. 1985 Apr 27;67(17):680-3. PubMed PMID: 3992389.

6. Torti SV, Torti FM. Iron and cancer: more ore to be mined. Nat Rev Cancer. 2013 May;13(5):342-55. doi: 10.1038/nrc3495. Epub 2013 Apr 18. Review. PubMed PMID: 23594855; PubMed Central PMCID: PMC4036554.

7. Fonseca-Nunes A, Jakszyn P, Agudo A. Iron and cancer risk–a systematic review and meta-analysis of the epidemiological evidence. Cancer Epidemiol Biomarkers Prev. 2014 Jan;23(1):12-31. doi: 10.1158/1055-9965.EPI-13-0733. Epub 2013 Nov 15. Review. PubMed PMID: 24243555.

8. Cross AJ, Pollock JR, Bingham SA. Haem, not protein or inorganic iron, is responsible for endogenous intestinal N-nitrosation arising from red meat. Cancer Res. 2003 May 15;63(10):2358-60. PubMed PMID: 12750250.

9. Bingham SA, Hughes R, Cross AJ. Effect of white versus red meat on endogenous N-nitrosation in the human colon and further evidence of a dose response. J Nutr. 2002 Nov;132(11 Suppl):3522S-3525S. PubMed PMID: 12421881.

10. Bullen JJ, Rogers HJ, Spalding PB, Ward CG. Natural resistance, iron and infection: a challenge for clinical medicine. J Med Microbiol. 2006 Mar;55(Pt 3):251-8. Review. PubMed PMID: 16476787.

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