Editing Zinc (section)

===Deficiency===
{{Main|Zinc deficiency}}

Nearly two billion people in the developing world are deficient in zinc. Groups at risk include children in developing countries and elderly with chronic illnesses.<ref name="Prasad2003">{{cite journal|last=Prasad|first =AS|title=Zinc deficiency : Has been known of for 40 years but ignored by global health organisations|journal=British Medical Journal |volume=326 |date=2003|pmid=12595353|pmc=1125304|doi=10.1136/bmj.326.7386.409|issue=7386|pages=409–410}}</ref> In children, it causes an increase in infection and diarrhea and contributes to the death of about 800,000 children worldwide per year.<ref name="Hambridge2007" /> The World Health Organization advocates zinc supplementation for severe malnutrition and diarrhea.<ref name="WHO2007">{{cite web|title=The impact of zinc supplementation on childhood mortality and severe morbidity|publisher=World Health Organization |url=https://www.who.int/child_adolescent_health/documents/zinc_mortality/en/index.html|date=2007| archive-url=https://web.archive.org/web/20090302033104/http://www.who.int/child_adolescent_health/documents/zinc_mortality/en/index.html |archive-date=March 2, 2009}}</ref> Zinc supplements help prevent disease and reduce mortality, especially among children with low birth weight or stunted growth.<ref name="WHO2007" /> However, zinc supplements should not be administered alone, because many in the developing world have several deficiencies, and zinc interacts with other [[Micronutrient|micronutrients]].<ref>{{cite journal |last=Shrimpton |first=R|author2=Gross R |author3=Darnton-Hill I |author4= Young M |title=Zinc deficiency: what are the most appropriate interventions?|journal=British Medical Journal|volume=330|date=2005|pmid=15705693|pmc =548733|doi=10.1136/bmj.330.7487.347|issue=7487|pages=347–349}}</ref> While zinc deficiency is usually due to insufficient dietary intake, it can be associated with [[malabsorption]], [[acrodermatitis enteropathica]], chronic liver disease, chronic renal disease, [[sickle cell disease]], [[diabetes]], [[malignancy]], and other chronic illnesses.<ref name="Prasad2003" />

In the United States, a federal survey of food consumption determined that for women and men over the age of 19, average consumption was 9.7 and 14.2&nbsp;mg/day, respectively. For women, 17% consumed less than the EAR, for men 11%. The percentages below EAR increased with age.<ref>{{cite web|author1=Moshfegh, Alanna |author2=Goldman, Joseph |author3=Cleveland, Linda|date=2005|url=https://www.ars.usda.gov/SP2UserFiles/Place/80400530/pdf/0102/usualintaketables2001-02.pdf|access-date=January 6, 2015|title=NHANES 2001–2002: Usual Nutrient Intakes from Food Compared to Dietary Reference Intakes|publisher=U.S. Department of Agriculture, Agricultural Research Service|at=Table A13: Zinc}}</ref> The most recent published update of the survey (NHANES 2013–2014) reported lower averages – 9.3 and 13.2&nbsp;mg/day – again with intake decreasing with age.<ref>[https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf What We Eat In America, NHANES 2013–2014] {{webarchive|url=https://web.archive.org/web/20170224042515/https://www.ars.usda.gov/ARSUserFiles/80400530/pdf/1314/Table_1_NIN_GEN_13.pdf |date=February 24, 2017 }}.</ref>

Symptoms of mild zinc deficiency are diverse.<ref name="DRI" /> Clinical outcomes include depressed growth, diarrhea, impotence and delayed sexual maturation, [[alopecia]], eye and skin lesions, impaired appetite, altered cognition, impaired immune functions, defects in carbohydrate use, and reproductive [[teratogenesis]].<ref name="DRI" /> Zinc deficiency depresses immunity,<ref>{{cite journal|last=Ibs|first=KH|author2=Rink L|title=Zinc-altered immune function|journal=Journal of Nutrition |volume=133|issue=5 Suppl 1|date=2003|pmid=12730441|pages=1452S–1456S|doi=10.1093/jn/133.5.1452S|doi-access=free}}</ref> but excessive zinc does also.<ref name="Rink2000" />

Despite some concerns,<ref name="Canada 2003">{{cite journal|url=https://www.vrg.org/nutrition/2003_ADA_position_paper.pdf|pmid=12778049|year=2003|title=Position of the American Dietetic Association and Dietitians of Canada: Vegetarian diets|journal=Journal of the American Dietetic Association|volume=103|issue=6|pages=748–765 |doi=10.1053/jada.2003.50142|url-status=live|archive-url=https://web.archive.org/web/20170114103128/http://www.vrg.org/nutrition/2003_ADA_position_paper.pdf|archive-date=January 14, 2017|author1=American Dietetic Association}}</ref> western vegetarians and vegans do not suffer any more from overt zinc deficiency than meat-eaters.<ref>{{cite journal|author=Freeland-Graves JH|author2=Bodzy PW|author3=Epright MA|title=Zinc status of vegetarians|pmid=7440860|journal=Journal of the American Dietetic Association |date=1980 |volume=77|pages=655–661|issue=6|doi=10.1016/S1094-7159(21)03587-X|s2cid=8424197}}</ref> Major plant sources of zinc include cooked dried beans, sea vegetables, fortified cereals, soy foods, nuts, peas, and seeds.<ref name="Canada 2003" /> However, [[phytates]] in many whole-grains and fibers may interfere with zinc absorption and marginal zinc intake has poorly understood effects. The zinc [[chelation|chelator]] [[phytic acid|phytate]], found in seeds and [[cereal]] [[bran]], can contribute to zinc malabsorption.<ref name="Prasad2003" /> Some evidence suggests that more than the US RDA (8&nbsp;mg/day for adult women; 11&nbsp;mg/day for adult men) may be needed in those whose diet is high in phytates, such as some vegetarians.<ref name="Canada 2003" /> The [[European Food Safety Authority]] (EFSA) guidelines attempt to compensate for this by recommending higher zinc intake when dietary phytate intake is greater.<ref name="EFSA" /> These considerations must be balanced against the paucity of adequate zinc [[biomarker]]s, and the most widely used indicator, plasma zinc, has poor [[sensitivity and specificity]].<ref>{{cite journal|last=Hambidge|first=M|title=Biomarkers of trace mineral intake and status|journal=Journal of Nutrition|volume=133|series=133|date=2003|pmid=12612181|issue=3|pages=948S–955S|doi=10.1093/jn/133.3.948S|doi-access=free}}</ref>