Iodine deficiency diseases are a group of diseases that are or can be caused by a lack of iodine in the body. Iodine is a dark purple nonmetallic element that belongs to the halogen group but is less reactive than other halogens. It has a boiling point of 13.5ºC and a melting point of 183ºC, when heated it emits purple vapors. It can be extracted from seawater, algae and oil well brines. It is also concentrated in the thyroid gland as part of the thyroid hormone. Iodine is found more in water than on land, this is because the iodine cycle is very slow and incomplete in most regions, so it takes a long time for the soil to regain iodine (Michael Zimmermann & Creswell J. Eastman, 2009 ), which is leached from the soil by processes such as leaching and continuous erosion. Then crops grown on such soil become iodine deficient. Carried away iodine usually ends up in seawater, hence areas of high iodine content (World Health Organization, 1995) and areas subject to frequent flooding, but can also occur in coastal regions (Michael Zimmermann & Creswell J. Eastman, 2009). Iodine is also necessary for the growth and development of the fetus. Iodine deficiency is also known as iodine deficiency and can cause miscarriage, stillbirth, mental retardation, growth retardation and goiter. Humans need a very small amount of iodine to prevent deficiencies (World Health Organization, 1995). According to the WHO book, humans only need 250 micrograms of iodine, which is only a quarter of a milligram (World Health Organization, 1995). This small amount is able to support humans and help them have a healthy life. The tables below show the recommended daily intake of iodine.Table 1: World Health Organization recommendations...... middle of document ......m-topic-overview?page=2Health. (2010, July 16). Hypothyroidism underactive thyroid. Retrieved August 20, 2012, from Web MD: http://www.webmd.com/a-to-z-guides/hypothyroidism-underactive-thyroid-symptoms-causes-treatmentsHealthwise Staff, Romito, K., & KIm, M.I. ( 2012, August 7). Hypothyroidism. Retrieved from UW Health: http://www.uwhealth.org/health/topic/major/hypooidism/hw145667.htmlHealthwise Staff, Thomson, E., & Lau, D.C. (2011, August 4). Hyperthyroidism. Retrieved November 2012 from UW Health: http://www.uwhealth.org/health/topic/major/hyperthyroidism/hw149039.html#sec-hw149039-HealthToolsMichael Zimmermann, M., & Creswell J. Eastman, M. (2009, 1 September). Iodine deficiency disorders. Retrieved May 28, 2012, from Thyroid Disease Disorders: http://www.thyroidmanager.org/chapter/the-iodine-deficiency-disorders/Ministry of Health. (2012).