Iron is an essential nutrient that is normally acquired from food1. The total amount of iron in the body is approximately 3 to 4 grams, which corresponds to a concentration of 40-50 mg of iron per kilogram of body weight2.
Iron plays a vital role in the transport and storage of oxygen, in oxidative metabolism and in cellular growth: Iron is an essential building block for haemoglobin, a protein present in the red blood cells that carries oxygen from the lungs to the tissues and organs. Haemoglobin is dependent on iron for its formation and oxygen-carrying property, and a lack of iron can cause a drop in the haemoglobin level and result in a condition called iron deficiency anaemia.
Iron deficiency is thought to be the most common cause of anaemia globally, although other nutritional deficiencies (e.g. folic acid and vitamin B12), inflammation, parasitic infections, and disorders that affect haemoglobin or red blood cell production, can also cause anaemia.
According to the World Health Organisation (WHO), non-pregnant adult women with a haemoglobin level below 12 g/dl are defined as anaemic, whereas for adult men this level is below 13 g/dl3.
1. Donovan, A., Roy, C. N. & Andrews, N. C. Physiology 21, 115-123 (2006)
2. Crichton, R. D., Bo.G; Geisser, P. Fourth Edition edn, (Bremen: UNI-MED, 2008)