Editing Human nutrition (section)

=== Vitamin and mineral malnutrition ===
Vitamins and minerals are essential to the proper functioning and maintenance of the human body.<ref name="stein-2010">{{Cite journal | title=Global Impacts of Human Mineral Malnutrition | last=Stein | first=A. J. | date=2010 | journal=Plant and Soil | doi=10.1007/s11104-009-0228-2 | volume=335 | issue=1/2 | pages=133–154 | bibcode=2010PlSoi.335..133S | s2cid=23959785}}</ref> There are 20 trace elements and minerals that are essential in small quantities to body function and overall human health.<ref name="stein-2010" />

[[Iron deficiency]] is the most common inadequate nutrient worldwide, affecting approximately 2 billion people.<ref name="ENA12">WHO. Iron deficiency anemia: assessment, prevention, and control. A guide for program managers. Geneva, WHO, 2001{{page needed|date=November 2013}}</ref> Globally, anemia affects 1.6 billion people, and represents a public health emergency in mothers and children under five.<ref name="Iron">WHO (2001). Iron deficiency anemia: Assessment, prevention, and control. A guide for program managers. Geneva, World Health Organization.</ref> The World Health Organization estimates that there exists 469 million women of reproductive age and approximately 600 million preschool and school-age children worldwide who are anemic.<ref name="ENA13">WHO, Centers for Disease Control. Worldwide prevalence of anemia 1993–2005: WHO global database of anemia. Geneva, WHO, 2008.{{page needed|date=November 2013}}</ref> [[Anemia]], especially iron-deficient anemia, is a critical problem for cognitive developments in children, and its presence leads to maternal deaths and poor brain and motor development in children.<ref name="Progress for Children" /> The development of [https://www.mayoclinic.org/diseases-conditions/anemia/symptoms-causes/syc-20351360#:~:text=Overview,weakness%20and%20shortness%20of%20breath. anemia] affects mothers and children more because infants and children have higher iron requirements for growth.<ref name="ENA14">W Institute of Medicine. Dietary reference intakes for vitamin A, vitamin K, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc. Washington DC, National Academy Press, 2001{{page needed|date=November 2013}}</ref> Health consequences for iron deficiency in young children include increased perinatal mortality, delayed mental and physical development, negative behavioral consequences, reduced auditory and visual function, and impaired physical performance.<ref name="ENA16">{{cite journal | vauthors=Algarín C, Peirano P, Garrido M, Pizarro F, Lozoff B | title=Iron deficiency anemia in infancy: long-lasting effects on auditory and visual system functioning | journal=Pediatric Research | volume=53 | issue=2 | pages=217–23 | date=February 2003 | pmid=12538778 | doi=10.1203/01.PDR.0000047657.23156.55 | doi-access=free}}</ref> The harm caused by iron deficiency during child development cannot be reversed and result in reduced academic performance, poor physical work capacity, and decreased productivity in adulthood.<ref name="Essential Nutrition Actions" /> Mothers are also very susceptible to iron-deficient anemia because women lose iron during menstruation, and rarely supplement it in their diet.<ref name="Essential Nutrition Actions" /> Maternal iron deficiency anemia increases the chances of maternal mortality, contributing to at least 18% of maternal deaths in low and middle income countries.<ref name="ENA20">"Global health risks – Mortality and burden of disease attributable to selected major risks". Geneva, WHO, 2009 (http://www.who.int/healthinfo/global_burden_disease/GlobalHealthRisks_report_full.pdf {{Webarchive|url=https://web.archive.org/web/20130810075230/http://www.who.int/healthinfo/global_burden_disease/GlobalHealthRisks_report_full.pdf |date=2013-08-10 }} accessed 31 July 2017).{{page needed|date=November 2013}}</ref>

[[Vitamin A]] plays an essential role in developing the immune system in children, therefore, it is considered an essential micronutrient that can greatly affect health.<ref name="Progress for Children" /> However, because of the expense of testing for deficiencies, many developing nations have not been able to fully detect and address vitamin A deficiency, leaving vitamin A deficiency considered a silent hunger.<ref name="Progress for Children" /> According to estimates, subclinical vitamin A deficiency, characterized by low retinol levels, affects 190 million pre-school children and 19 million mothers worldwide.<ref name="VitAWHO">WHO (2009). Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO Global Database on Vitamin A Deficiency. Geneva, World Health Organization. {{cite web | url=http://www.edu-lib.us/whqlibdoc.who.int/publications/2009/9789241598019_eng.pdf | title=Archived copy | access-date=1 March 2014 | url-status=usurped | archive-url=https://web.archive.org/web/20150923233815/http://www.edu-lib.us/whqlibdoc.who.int/publications/2009/9789241598019_eng.pdf | archive-date=23 September 2015}}</ref>

The WHO estimates that 5.2 million of these children under five are affected by night blindness, which is considered clinical vitamin A deficiency.<ref name="ENA9">WHO. Global prevalence of vitamin A deficiency in populations at risk 1995–2005: WHO Global database of vitamin A deficiency. Geneva, WHO, 2009.</ref> Severe vitamin A deficiency (VAD) for developing children can result in visual impairments, anemia and weakened immunity, and increase their risk of morbidity and mortality from infectious disease.<ref name="ENA10">Sommer A, West KP Jr. Vitamin A deficiency: health, survival, and vision. New York, Oxford University Press, 1996 p. 19 {{ISBN|0195088247}}</ref> This also presents a problem for women, with WHO estimating that 9.8 million women are affected by night blindness.<ref name="ENA11">{{cite journal | vauthors=Lozoff B, Jimenez E, Wolf AW | title=Long-term developmental outcome of infants with iron deficiency | journal=The New England Journal of Medicine | volume=325 | issue=10 | pages=687–94 | date=September 1991 | pmid=1870641 | doi=10.1056/NEJM199109053251004 | doi-access=free}}</ref> Clinical vitamin A deficiency is particularly common among pregnant women, with prevalence rates as high as 9.8% in South-East Asia.<ref name="VitAWHO" />

Estimates say that 28.5% of the global population is iodine deficient, representing 1.88 billion individuals.<ref name="Iodine">{{cite journal | vauthors=Andersson M, Karumbunathan V, Zimmermann MB | title=Global iodine status in 2011 and trends over the past decade | journal=The Journal of Nutrition | volume=142 | issue=4 | pages=744–50 | date=April 2012 | pmid=22378324 | doi=10.3945/jn.111.149393 | doi-access=free}}</ref> Although salt iodization programs have reduced the prevalence of iodine deficiency, this is still a public health concern in 32 nations. Moderate deficiencies are common in Europe and Africa, and over consumption is common in the Americas.<ref name="GNP" /> Iodine-deficient diets can interfere with adequate thyroid hormone production, which is responsible for normal growth in the brain and nervous system. This ultimately leads to poor school performance and impaired intellectual capabilities.<ref name="Progress for Children" />