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Iron is of immense significance in human nutrition. The human body of adults contains between 3 to 4 g of the nutrient of which about 60 to 70 per cent is present in the blood (Hb iron) as circulating iron and the rest 1 to 1.5 g as storage iron. Each gram of hemoglobin contains about 3.34 mg of iron.
Functions of Iron:
Iron is necessary for carrying out several functions in the body including the formation of hemoglobin, brain development and function, regulation of body temperature, muscle activity and catecholamine metabolism. Lack of iron directly affects the immune system. It diminishes the number of T- cells and the production of antibodies. Besides, hemoglobin, iron is a component of myoglobin, the cytochromes, catalase and certain enzyme systems.
Iron is essential for binding oxygen to the blood cells. Its central function is ‘oxygen transport’ and cell respiration.
Iron Sources:
The two forms of iron are haem –iron and non –haem iron. Haem iron is better absorbed than non-haem iron. Foods rich in haem iron are livers, meat, poultry and fish. They are not only important sources of readily available iron but also promote the absorption of non haem irons in plant foods eaten at the same time. The iron content of milk is low in all mammalian species. Iron content of breast milk averages less then 0.2 mg /dl and is well utilized. Foods containing non haem iron are those of vegetable origin such as cereals, green leafy vegetables, legumes, nuts and oil seeds, jaggery and dry fruits.
The bioavailability of non haem iron is poor owing to the presence of phytates, oxylates, carbonates, phosphates and dietary fiber which interfere with the absorption of iron. Other foods that inhibit the absorption of the macronutrient are milk, eggs and tea. In some areas significant amounts of the nutrient may be derived from cooking in iron vessels.
Absorption:
Iron is mostly absorbed from duodenum and upper small intestine in the ferrous state as per the specific needs of the body. The rate of iron absorption is influenced by a great many factors such as the iron reserves of the individual, the presence of inhibitors such as phosphates and promoters like ascorbic acids and disorders of duodenum and jejunum like celiac disease, tropical sprue. Absorption of the nutrient is greater when there is an increase in demand for iron as in pregnancy.
The absorbed iron is transported as plasma ferritin and stored in the liver, spleen, bone marrow and kidney. The characteristic feature of iron metabolism is conservation. When red blood cells are broken down the liberated iron is re-utilized in the formation of new red cells. Calcium, copper, zinc, lead and phosphates inhibit iron absorption.
Iron Losses from the body:
The total daily iron loss of an adult is 1 mg and 2 mg in menstruating women. Major routes of iron loss are:
Hemorrhage: It is a condition characterized by blood loss from the body. The causes for this may be physiological or pathological such as menstruation, childbirth, hookworms, malaria, hemorrhoids and peptic ulcer.
Basal Losses: These are marked by the excretion through urine, sweat and bile.
Deficiency:
The most common nutritional deficiency disease is anemia. About 30 per cent of the total world population is anemic. It often leads to the irreversible impairment of the child’s learning ability. In adults, it results in impaired work capacity. The causes of iron deficiency are hookworm infection, nutritional deficiency of iron, repeated pregnancy, chronic blood loss, nephrosis, kidney glomeruli mechanism is in efficient and proteinurea results. The deficiency of the nutrient is marked by microcytic hypochromic anemia. It results when the hemoglobin level is less than 12 gm /dl. When the level is lower than 10 gm, body cells lack oxygen and the individual becomes uninterested in surroundings.
Treatment of Iron:
Oral iron supplementation is the treatment of choice. A number of iron supplements are available in the market in the form of tablets, capsules and injections.
Before taking any mineral supplements it is essential for you to consult a registered medical practitioner in order to determine if the nutrient is required by your body or not. You must also make note of any of the diseases or ailments you might be suffering from such as high blood pressure, coronary heart disease, depression, kidney problem, gastro intestinal disease, high cholesterol levels etc. you must also consider your present medical condition, if you are allergic to any prescription of over the counter (OTC) drugs
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