Iron is vital in human nutrition as the adult human body contains 3-4 grams of iron. Haem-iron and non-haem iron are the two types of iron. Foods rich in haem-iron include meat, liver, fish, and poultry. Foods that are high in non-haem iron are those of vegetable origin, like green leafy vegetables, cereals, legumes, oilseeds, nuts, dry fruits and jiggery. Iron is vital for numerous body functions, including hemoglobin formation, brain development and function, muscle activity, regulation of body temperature and catecholamine. Deficiency of iron affects immune system, reduces the number of T-cells and production of antibodies. Iron is also necessary for binding oxygen to body cells as its main function is oxygen transport and cell respiration. It works as an anti-cancer agent. Iron increases energy level of the body, improving physical performance. It prevents insomnia.