Iron is an essential element as it takes part in a wide variety of metabolic processes, including oxygen transport, deoxyribonucleic acid (DNA) synthesis, and electron transport. Disorders of iron metabolism are very common and include a broad spectrum of diseases with diverse clinical manifestations, ranging from anemia to iron overload (1).
Bioavailability
Heme and nonheme are two different forms of dietary iron. The sources of heme iron are hemoglobin and myoglobin found in meat, poultry, and fish, whereas sources of nonheme iron are cereals, pulses, legumes, fruits, and vegetables. Heme iron is highly bioavailable (15%-35%) and dietary factors show little effect on its absorption, whereas nonheme iron absorption is much lower (2%-20%) and is influenced by the presence of other food components. The major inhibitors of iron absorption are phytic acid, polyphenols, calcium, and peptides from partially digested proteins. Ascorbic acid is an enhancer of iron absorption (1).
Dietary iron from plant foods is called nonheme iron and is usually in ferric form. Heme iron is absorbed better than nonheme iron because heme iron can be absorbed directly into the small intestine, whereas nonheme iron requires a carrier. Vitamin C acts as a carrier and increases iron absorption (2).
Iron requirements
Iron deficiency is commonly found in parts of a population that have inadequate access to foods rich in absorbable iron & during stages of high iron demand. Children, adolescents, and women of reproductive age, in particular during pregnancy are at a higher risk of iron deficiency (1)
Iron demand is more in infants and adolescents as a result of rapid growth. Women of reproductive age require more iron due to excessive blood loss during menstruation. During pregnancy, there is a significant increase in iron requirement because of the rapid growth of the placenta and the fetus. Adult men and postmenopausal women are at low risk of iron deficiency as the amount of iron in a normal diet are usually sufficient to cover their physiological requirements (1).
Iron deficiency anemia
When Fe stores (i.e. serum ferritin- sFer) have become depleted but Hemoglobin (Hgb) has not yet declined to a level indicative of anemia, this is the beginning of functional or subclinical iron deficiency (ID). Under conditions of severe Iron Deficiency, Hemoglobin synthesis may become compromised in addition to depleted iron stores causing iron deficiency anemia (IDA). With IDA, a range of physical performance measures are affected due to reduced oxygen transport.
Supports immunity
Iron works as cofactor for many enzymes of the immune system. Its deficiency is reported to cause impairment of cell-mediated immunity, mucosal immunity and proliferation of T- cells.
It is very important to monitor the ferritin levels which indicate the iron stores of the body.