Iron in Nutrition:
Iron is a trace element and a very important micro-nutrient. The total amount of iron in the body of an adult male is about 90 mg/kg or a total of 3.8 g, in a woman 2.3 g and in new born it is 250 mg. All body cells contain some iron.
Approximately 70% of the iron is in hemoglobin, 5% is in myoglobin in muscles, 5% is present in cellular constituents including the iron containing enzymes and 20% is stored as Ferritin by the liver, spleen and bone narrow. In healthy men, the iron reserve is about 1000mg, but in menstruating women, it is only 200-400 mg. Iron circulates in the plasma bound to a beta globulin is called Transferrin.
Function of Iron:
1. The most important function of iron is to carry oxygen in the body. Hemoglobin is the principal component of the red blood cells and it has most of the iron of the body.
Hemoglobin acts as a carrier of oxygen from the lungs to the tissues and helps in the return of carbon dioxide to the lungs. All the cells of our body continuously require oxygen for the oxidation reduction reactions.
2. Myoglobin is an iron-protein complex in the muscle which stores some oxygen for immediate use by the cells.
3. Some enzymes contain iron – like the catalyses, the Cytochromes in hydrogen ion transport and xanthine oxidase. Iron is also required as a co-factor for some other enzymes.