Iron

About Iron

Iron is an essential trace mineral found in hemoglobin, which carries oxygen in the blood, in myoglobin, which stores oxygen in muscle, and in many enzymes including the cytochromes of the electron transport chain. Official recommended intakes vary by age, sex and life stage. Iron deficiency is the most common nutritional deficiency in the world, with infants, adolescent girls and pregnant women at greatest risk. Heme iron from meat and fish is absorbed much more efficiently than non heme iron from plants. Vitamin C enhances non heme iron absorption by reducing ferric iron to the ferrous form, while phytates, tea polyphenols and calcium inhibit it. Absorption is regulated by the liver hormone hepcidin. Deficiency progresses from depleted stores with low ferritin, through iron deficient red cell production, to iron deficiency anemia, with fatigue, pallor, breathlessness and spoon shaped nails. Iron overload in hereditary hemochromatosis or after repeated transfusions damages the liver, heart and pancreas, causing cirrhosis, cardiomyopathy, diabetes and arthritis.