Iron is an essential mineral because it transports oxygen in the blood to all the cells in the body. Most of the iron in the body is found in the haemoglobin of the red blood cells. Iron deficiency can cause fatigue and palpitation of the heart, and serious deficiency can cause problems with the oral mucosa and the mucous membrane of the tongue, and it can also cause skin and nail problems. Iron contributes to the normal production of red blood cells and haemoglobin, as well as contributing to normal transportation of oxygen in the body and normal energy-yielding metabolism. Iron also helps the immune system to function normally and reduces fatigue and exhaustion.