The World Health Organization considers Iron deficiency the number one nutritional disorder in the world. As many as 80% of the world's population may be Iron deficient, while 30% may have Iron deficiency anemia. Iron is one of the most abundant metals on Earth and it is essential to most life forms and to normal human physiology. It is an integral part of many proteins and enzymes that maintain good health. In humans, Iron is an essential component of proteins involved in oxygen transport. It is also essential for the regulation of cell growth and differentiation. A deficiency of Iron limits oxygen delivery to cells, resulting in fatigue, poor work performance, and decreased immunity. On the other hand, excess amounts of Iron can result in toxicity and even death. Iron is vital for all living organisms because it is essential for multiple metabolic processes, including oxygen transport, DNA synthesis, and electron transport. Iron equilibrium in the body is regulated carefully to ensure that sufficient Iron is absorbed in order to compensate for body losses of Iron.
Iron supplements are used to treat or prevent low blood levels of Iron (e.g., for anemia or during pregnancy). The best sources of Iron include dried beans; dried fruits; eggs (especially egg yolks); Iron-fortified cereals; liver; lean red meat (especially beef); oysters; poultry- dark red meat; salmon; tuna; whole grains; etc. Iron deficiency develops gradually and usually begins with a negative iron balance, when Iron intake does not meet the daily need for dietary Iron. This negative balance initially depletes the storage form of Iron while the blood hemoglobin level, a marker of iron status, remains normal. Iron deficiency anemia is an advanced stage of iron depletion. It occurs when storage sites of iron are deficient and blood levels of iron cannot meet daily needs. Blood hemoglobin levels are below normal with iron deficiency anemia. Iron deficiency anemia can be associated with low dietary intake of Iron, inadequate absorption of Iron, or excessive blood loss. Women of childbearing age, pregnant women, preterm and low birth weight infants, older infants and toddlers, and teenage girls are at greatest risk of developing Iron deficiency anemia because they have the greatest need for Iron. Women with heavy menstrual losses can lose a significant amount of Iron and are at considerable risk for iron deficiency. Adult men and post-menopausal women lose very little Iron, and have a low risk of Iron deficiency.
References:
Office of Dietary Supplements. http://dietary-supplements.info.nih.gov/factsheets/iron.asp
WebMD. http://www.emedicine.com/med/topic1188.htm
Medline Plus. http://www.nlm.nih.gov/medlineplus/ency/article/002422.htm
