Abstract Iron is essential nutrients, excesses or deficiencies of which cause impaired cellular functions and eventually cell death. Systemic iron deficiency generates cellular iron deficiency, which in human results in diminished work capacity, reduced intellectual capacity, diminished growth, alterations in bone mineralization, and diminished immune response. Iron is similarly required in numerous essential proteins, such as the heme-containing proteins, electron transport chain and microsomal electron transport proteins, and iron-sulfur proteins and enzymes such as ribonucleotide reductase, prolyl hydroxylase phenylalanine hydroxylase, tyrosine hydroxylase and aconitase. The essentiality of iron resides in their capacity to participate in one electron exchange reactions. Iron metabolism is very fine tuned. The free molecule is very toxic; there¬fore, complex regulatory mechanisms have been developed in mammalian to insure adequate intestinal ab¬sorption, transportation, utilization, and elimination.