Iron is an essential part of hemoglobin (heme portion), myoglobin in muscles, certain enzymes in mitochondria etc. It is stored in the form of ferritin in the body and transported in the blood as transferrin.
The average body of adult humans has 3 to 4 gms of iron, women have about ½ gm less than their male counterparts. About 2.5 gms of iron is in the redblood cells (formed or forming) and ½ to 1 gm is in the storage form. Circulating iron in plasma is 5 to 7 mg and about ½ gm is in myoglobin and various enzymes.
Diet in western countries contains about 10-15 mg of iron daily. In the Asian countries quantity of iron is about ½ to 2/3 of the western diet. Non-vegetarian food iron is absorbed to the extent of 30 % while in vegetarian food only about 10 % of iron is absorbed. Phytates, tannates, phosphates reduce iron absorption while vitamin C enhances it. Iron in vegetarian food is in ferric form and absorption is mainly in ferrous form.
25 to 30 mg of iron may be released from dying RBCs and most of this is very efficiently reused by the body. Iron is lost from the body in sweat, skin and gastrointestinal cells which are shed continuously from the lining of skin and GIT.
Iron is absorbed mainly from duodenum and absorption increases in iron deficiency states. It is decreased in iron surplus states.
Iron deficiency results in anemia with small RBCs which have reduced hemoglobin. The deficiency states are diagnosed by S Iron , S ferritin, S transferrin level and RBC indices.
Common causes of Iron Deficiency are
Reduced dietary intake
Increased losses in the body from bleeding (menstruation, worms, GI bleeds, nose bleeds , injuries )
Reduced absorption (antacids, GI diseases)
Most woman are chronically deficient in Iron due to menstrual losses and their Hemoglobin is closer to 13 compared to 15 in men. Iron deficiency anemia is a common cause of poor health , fatigue, pregnancy complications etc.
Treatment of Iron deficiency
By increasing dietary Iron (fortified wheat flour) etc and iron supplements in the form of oral and injectable iron preparations. Oral drugs are safer but may cause GI Side-effects. Most Injectable preparations available nowadays have few serious reactions but these have to be administered under supervision.