Editing Iron (section)

===Excess===
{{Main|Iron overload}}
[[Human iron metabolism|Iron uptake]] is tightly regulated by the human body, which has no regulated physiological means of excreting iron. Only small amounts of iron are lost daily due to mucosal and skin epithelial cell sloughing, so control of iron levels is primarily accomplished by regulating uptake.<ref>{{cite book|author1=Ramzi S. Cotran|author2=Vinay Kumar|author3=Tucker Collins|author4=Stanley Leonard Robbins|title=Robbins pathologic basis of disease|url={{Google books|kdhrAAAAMAAJ|keywords=|text=|plainurl=yes}}|access-date= 27 June 2012|date=1999|publisher=Saunders|isbn=978-0-7216-7335-6}}</ref> Regulation of iron uptake is impaired in some people as a result of a [[Genetic disorder|genetic defect]] that maps to the HLA-H gene region on [[chromosome 6]] and leads to abnormally low levels of [[hepcidin]], a key regulator of the entry of iron into the circulatory system in mammals.<ref name="pmid12663437">{{cite journal|author=Ganz T|title=Hepcidin, a key regulator of iron metabolism and mediator of anemia of inflammation|journal=Blood|volume=102|issue=3|pages=783–8|date=August 2003|pmid=12663437|doi=10.1182/blood-2003-03-0672|s2cid=28909635|doi-access=free}}</ref> In these people, excessive iron intake can result in [[iron overload disorder]]s, known medically as [[hemochromatosis]].<ref name="lpi" /> Many people have an undiagnosed genetic susceptibility to iron overload, and are not aware of a family history of the problem. For this reason, people should not take iron supplements unless they suffer from [[iron deficiency (medicine)|iron deficiency]] and have consulted a doctor. Hemochromatosis is estimated to be the cause of 0.3–0.8% of all metabolic diseases of Caucasians.<ref>{{Cite journal|title=Hereditary hemochromatosis|journal=Rev Méd Interne|date=2000 |volume=21 |issue=11 |pages=961–71 |doi=10.1016/S0248-8663(00)00252-6 |pmid=11109593|last1=Durupt|first1=S.|last2=Durieu|first2=I.|last3=Nové-Josserand|first3=R.|last4=Bencharif|first4=L.|last5=Rousset|first5=H.|last6=Vital Durand|first6=D.}}</ref> <!--f[[MRI]] studies show that iron accumulates in the [[hippocampus]] of the brains of those with [[Alzheimer's disease]] and in the [[substantia nigra]] of those with [[Parkinson disease]].<ref>{{Cite journal| url = https://archneur.highwire.org/cgi/content/abstract/66/3/371 |pmid= 19273756|doi = 10.1001/archneurol.2008.586|date = 2009|last1 = Brar|first1 = S.|last2 = Henderson|first2 = D.|last3 = Schenck|first3 = J.|last4 = Zimmerman|first4 = E.A.|title = Iron accumulation in the substantia nigra of patients with Alzheimer disease and parkinsonism|volume = 66|issue = 3|pages = 371–74|journal = Archives of Neurology}}</ref>-->

Overdoses of ingested iron can cause excessive levels of free iron in the blood. High blood levels of free ferrous iron react with [[peroxide]]s to produce highly reactive [[free radical]]s that can damage [[DNA]], [[proteins]], [[lipids]], and other cellular components. Iron toxicity occurs when the cell contains free iron, which generally occurs when iron levels exceed the availability of [[transferrin]] to bind the iron. Damage to the cells of the [[Human gastrointestinal tract|gastrointestinal tract]] can also prevent them from regulating iron absorption, leading to further increases in blood levels. Iron typically damages cells in the [[heart]], [[liver]] and elsewhere, causing adverse effects that include [[coma]], [[metabolic acidosis]], [[Shock (circulatory)|shock]], [[liver failure]], [[coagulopathy]], long-term organ damage, and even death.<ref name="Cheney" /> Humans experience iron toxicity when the iron exceeds 20 milligrams for every kilogram of body mass; 60 milligrams per kilogram is considered a [[lethal dose]].<ref name="emed-topic285">{{cite web|url=https://www.emedicine.com/emerg/topic285.htm|title=Toxicity, Iron
| publisher = Medscape|access-date=23 May 2010}}</ref> Overconsumption of iron, often the result of children eating large quantities of [[ferrous sulfate]] tablets intended for adult consumption, is one of the most common toxicological causes of death in children under six.<ref name="emed-topic285" /> The [[Dietary Reference Intake]] (DRI) sets the Tolerable Upper Intake Level (UL) for adults at 45 mg/day. For children under fourteen years old the UL is 40 mg/day.<ref name="IOM">{{citation|title=Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals |publisher=Food and Nutrition Board, Institute of Medicine, National Academies |year=2004 |url=https://www.iom.edu/Global/News%20Announcements/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Summary_Listing.pdf |access-date=2009-06-09 |url-status=dead |archive-url=https://web.archive.org/web/20130314000722/https://www.iom.edu/Global/News%20Announcements/~/media/Files/Activity%20Files/Nutrition/DRIs/DRI_Summary_Listing.pdf |archive-date=14 March 2013 }}</ref>

The medical management of iron toxicity is complicated, and can include use of a specific [[chelation|chelating]] agent called [[deferoxamine]] to bind and expel excess iron from the body.<ref name="Cheney">{{Cite journal| last1 =Cheney|first1 =K.| last2 =Gumbiner|first2 =C.| last3 = Benson|first3 =B.| last4 = Tenenbein|first4 =M.|title=Survival after a severe iron poisoning treated with intermittent infusions of deferoxamine |journal=J Toxicol Clin Toxicol |volume=33 |issue=1 |pages=61–66 |date=1995 |pmid=7837315 |doi=10.3109/15563659509020217}}</ref><ref>{{Cite journal| last = Tenenbein|first = M.|title=Benefits of parenteral deferoxamine for acute iron poisoning |journal=J Toxicol Clin Toxicol |volume=34 |issue=5 |pages=485–89 |date=1996 |pmid=8800185 |doi=10.3109/15563659609028005}}</ref><ref name="pmid21102602">{{cite journal |vauthors=Wu H, Wu T, Xu X, Wang J, Wang J | title = Iron toxicity in mice with collagenase-induced intracerebral hemorrhage | journal = J Cereb Blood Flow Metab | volume = 31 | issue = 5 | pages = 1243–50 |date=May 2011 | pmid = 21102602 | doi =10.1038/jcbfm.2010.209 | pmc=3099628}}</ref>