AN OVERVIEW ON IRON
Iron is one of the crucial minerals required by our body. Approximately 70% of iron is found in our red blood cells as haemoglobin and in muscle cells as myoglobin. Iron performs many important roles - it is needed for the synthesis of red blood cells, collagen, energy metabolism, normal functioning of immune cells and neurotransmitters. Iron is required to serve many biochemical processes in the body. Haemoglobin is the main carrier of oxygen and nutrients, and transports them to various cells and organs of the body. For the formation of haemoglobin, we need iron and proteins. Lack of iron can lead to insufficient supply of oxygen, making us feel tired, lethargic and weak.
Role of Iron in diet:
⋅ Improves energy production
⋅ Lowers fatigue
⋅ Enhances cognitive function
⋅ Strengthens immune system
⋅ Carries oxygen in body
⋅ Produces red blood cells
⋅ Maintains healthy cell division
Since iron is present in our muscles as myoglobin, it supports the increased requirement of nutrients and oxygen during vigorous exercise schedule for better muscle contraction. We get iron from two sources - plants and animals. Plant based iron rich foods like cereals, vegetables, fruits, vegetables and legumes provide iron in the non-heme form, whereas animal-based foods like meat, fish and poultry contain heme form of iron. We eat food to derive energy and iron plays a significant role during energy metabolism. Iron is utilised by variety of enzymes which are involved in metabolic pathways like oxidative phosphorylation. Therefore, iron deficiency can critically affect our energy levels making it difficult for us to concentrate, focus and perform daily activities.
How much iron is needed by the body?
As per the Indian Council of Medical Research (ICMR), daily iron requirement of an adult male is 17 mg and for women is 21 mg. Daily recommended allowance of iron for pregnant women is higher and may increase to 35 mg per day. This is because the blood volume and formation of red blood cells are increased during pregnancy for the growing foetus. The absorption of iron is also increased and its inadequate supply might lead to premature delivery or low birth weight and chances of rise in cognitive disabilities. We additionally need iron for strong immune health. Lack of iron makes us prone to infections and diseases. Iron has been shown to play a role in activation of NF-κB which is associated with innate immunity and inflammation.
Iron is stored in the form of ferritin primarily in liver, spleen and bone marrow. Phytates are considered as the major inhibitor of iron absorption whereas vitamin C is known to enhance its bioavailability. Iron deficiency can result in anaemia and is seen due to various reasons like inadequate dietary intake, pregnancy, menstruation, excessive bleeding, colon cancer, haemorrhoids, renal disorders and alcoholism. Hence, it is very important to ensure that daily iron needs are met. Diet should be rich in iron and vitamin C rich foods. It is better to avoid intake of tea and coffee along with iron rich meals. Supplementation and using fortified foods is another way to address daily iron needs.
Iron deficiency :
Iron deficiency starts from depletion of iron stores (mild iron deficiency), progresses to iron-deficiency erythropoiesis (erythrocyte production), and eventually marks iron deficiency anemia (IDA). With iron-deficiency erythropoiesis (also known as marginal iron deficiency), iron stores get reduced and transferrin saturation declines, however, hemoglobin levels are normally within the normal range. IDA is characterized by low hemoglobin concentrations, and decrease in hematocrit (the proportion of red blood cells in blood by volume) and mean corpuscular volume (a measure of erythrocyte size). Serum ferritin concentration, which is a measure of the body’s iron stores, is at present the most efficient and economical test for diagnosing iron deficiency. As serum ferritin lowers in the first stage of iron depletion, it can identify low iron status prior to the onset of IDA. A serum ferritin concentration of less than 30 mcg/L suggests iron deficiency, and a reading lower than 10 mcg/L suggests IDA. However, serum ferritin is subjected to be influenced by inflammation , which elevates serum ferritin concentrations.
Hemoglobin and hematocrit tests are the most widely used measures to detect patients for iron deficiency. Hemoglobin concentrations are very often combined with serum ferritin measurements to detect IDA. If hemoglobin concentrations are less than 11 g/dL in children under 10 years of age, or less than 12 g/dL in individuals of 10 years or older in age, it suggests IDA. If we look the values, the normal hematocrit values are approximately 41% to 50% in case of males and 36% to 44% in case of females.
By now, it is evident that iron is a micronutrient that plays various roles in a human body and its deficiency can be life threatening . Thus it becomes very important to include the mentioned dietary sources and , if needed, supplementation as advised by the doctor to maintain optimal iron levels.