Iron is an essential nutrient. It is needed in small quantities to help form normal red blood cells (rbcs). Iron is a critical part of haemoglobin, the protein in red blood cells that binds oxygen in the lungs and releases it as blood travels to other parts of the body.Cognitive learning psychology definition low iron levels can lead to anaemia and the production of rbcs that are small (microcytic) and pale (hypochromic). Large quantities of iron can be toxic to the body, and absorption of too much iron over time can lead to the accumulation of iron compounds in organs and tissues.Cognitive learning psychology definition this can damage organs such as the liver, joints, heart, and pancreas.

Iron is normally absorbed from food in the small intestine and transported throughout the body bound to transferrin, a transport protein produced by the liver.Cognitive learning psychology definition about 70% of the iron transported is incorporated into the haemoglobin inside rbcs. Most of the rest is stored in the tissues as ferritin or haemosiderin.Cognitive learning psychology definition small amounts of iron are used to produce other proteins such as myoglobin (the oxygen carrying protein in muscle), and some enzymes.

• serum iron - measures the concentration of iron in the blood.Cognitive learning psychology definition the amount of iron within the blood varies throughout the day, and from one day to the next. An blood (serum) iron test is therefore not a useful measure of iron status if it is used on its own unless iron overdose is suspected.Cognitive learning psychology definition serum iron is therefore often requested in combination with other tests of iron status. Such tests include transferrin saturation, ferritin, TIBC (total iron binding capacity) and UIBC (unbound iron binding capacity).Cognitive learning psychology definition

• transferrin or TIBC (total iron binding capacity). A laboratory will often measure one of either TIBC or transferrin. Transferrin is the main transport protein to which iron is bound in the blood.Cognitive learning psychology definition TIBC is a measure of all the proteins in the blood that are available to bind with iron (including transferrin). The TIBC test is a good indirect measurement of transferrin, as transferrin is the primary iron-binding protein.Cognitive learning psychology definition the body produces transferrin in relationship to the need for iron. When iron stores are low, transferrin levels increase and vice versa. In healthy people, about one-third of the binding sites on transferrin are used to transport iron.Cognitive learning psychology definition

Tests for iron, ferritin, transferrin saturation, and a transferrin or TIBC may be requested when a doctor suspects that a person may have a chronic iron overload.Cognitive learning psychology definition in the absence of a history of multiple transfusions, the most common cause of iron overload is a genetic condition called hereditary haemochromatosis.Cognitive learning psychology definition HFE genetic testing (see below) may be requested to help confirm a diagnosis of hereditary haemochromatosis and sometimes when a person has a family history of haemochromatosis.Cognitive learning psychology definition the signs and symptoms of iron overload are as follows:

• haemoglobin and haematocrit - these tests are performed as part of a full blood count (FBC).Cognitive learning psychology definition A low value for either test indicates that a person has anaemia. Iron deficiency is a very common cause of anaemia. The average size of red cells (mean cell volume or MCV) and the average amount of haemoglobin in red cells (mean cell haemoglobin or MCH) are also measured in an FBC.Cognitive learning psychology definition in iron deficiency, insufficient haemoglobin is made, causing the red blood cells to be smaller and paler than normal. Both MCV and MCH are low.Cognitive learning psychology definition

• HFE gene test - haemochromatosis is a genetic disease in caucasians that causes the body to absorb too much iron. It is usually due to an inherited abnormality in a specific gene, called the HFE gene that affects the amount of iron absorbed from the gut.Cognitive learning psychology definition in people who have two copies of the abnormal gene too much iron can be absorbed and excess iron is deposited in many different organs, where it can cause damage and organ failure.Cognitive learning psychology definition the HFE gene test determines whether a person has the mutations that cause the disease. The most common mutation is called C282Y. Not everyone with this genetic mutation will develop haemochromatosis.Cognitive learning psychology definition

• zinc protoporphyrin (ZPP) - protoporphyrin is the precursor to the part of haemoglobin (haem) that contains iron. If there is not enough iron, another metal, such as zinc, will attach to the protoporphyrin instead.Cognitive learning psychology definition the amount of zinc protoporphyrin in red cells is increased in iron deficiency. Sometimes ZPP (and its ratio to haem levels) is used as an early indicator of iron deficiency in children.Cognitive learning psychology definition however, the test is not specific for iron deficiency, and elevated values must be confirmed by other tests. The test is therefore rarely used in the UK, but still has a role in developing countries.Cognitive learning psychology definition

Iron deficiency can range in severity. The mildest stage is iron depletion, which means the amount of functioning iron in the body is adequate, but the body does not have any extra iron stores.Cognitive learning psychology definition serum iron concentration may be normal in this stage, but ferritin levels will be low. As iron deficiency worsens, all of the stored iron is used and the body begins to produce more transferrin to increase iron transport.Cognitive learning psychology definition serum iron becomes low, and transferrin and TIBC are high. As this stage progresses, fewer red cells are produced. In iron-deficiency anaemia, the number of red cells is decreased and many of the cells appear smaller and paler than normal.Cognitive learning psychology definition

Iron overload may be acute or chronic. Acute iron overload is suspected if the iron level is high but TIBC and ferritin are normal. If the person has a clinical history consistent with iron overdose, then iron poisoning is the most likely diagnosis.Cognitive learning psychology definition iron poisoning occurs when a large amount of iron is taken all at once. While this is rare, it most commonly occurs in children who ingest their parents' iron supplements.Cognitive learning psychology definition in some cases, iron poisoning can be fatal.

Chronic iron overload can occur due to a genetic condition called hereditary haemochromatosis, following multiple blood transfusions or due to other conditions such as liver disease.Cognitive learning psychology definition hereditary haemochromatosis occurs in persons with two genetic mutations of the HFE gene. The most common mutation is known as C282Y. However, many people who have this genetic mutation will not develop symptoms for their entire life, while others will start to develop symptoms such as joint pain, abdominal pain, and weakness in their 30s or 40s.Cognitive learning psychology definition iron overload may also occur in people who have multiple transfusions, such as may happen with thalassemia or other forms of anaemia. The iron from each transfused unit of blood stays in the body, eventually causing a large build up in the tissues.Cognitive learning psychology definition some people who abuse alcohol with chronic liver disease may also develop iron overload.

Normal iron concentrations are maintained by a balance between the amount of iron taken into the body and the amount of iron lost.Cognitive learning psychology definition normally, a small amount of iron is lost each day, so if too little iron is taken in, deficiency will eventually develop. Unless a person has a poor diet, there is usually enough iron to prevent iron deficiency and/or iron deficiency anaemia in healthy people.Cognitive learning psychology definition in certain situations, there is an increased need for iron. Persons with chronic bleeding from the gut (usually from ulcers or tumours, long term usage of nonsteroidal anti-inflammatory drugs [nsaids] such as ibuprofen or aspirin) or women with heavy menstrual periods will lose more iron than normal and can develop iron deficiency.Cognitive learning psychology definition iron from food is absorbed into the bloodstream in the small intestine. An intestinal disorder, such as celiac disease, which affects the intestine's ability to absorb nutrients from digested food, can lead to iron deficiency anemia.Cognitive learning psychology definition women who are pregnant or breast feeding supply iron to their baby and can develop iron deficiency if not enough extra iron is taken in. Children, especially during times of rapid growth, may need extra iron and can develop iron deficiency.Cognitive learning psychology definition

Low serum iron can also occur in states where the body cannot use iron properly despite sufficient iron stores. In many chronic diseases, especially cancers, autoimmune diseases, and chronic infections (including AIDS), the body cannot properly use iron to make more red cells, and so an anaemia develops.Cognitive learning psychology definition this disorder is known as “functional iron deficiency” or “anaemia of chronic disease”. The blood tests in persons with this condition will normally show low levels of serum iron and transferrin but normal or even high ferritin levels.Cognitive learning psychology definition

Iron deficiency refers to a decrease in the amount of iron stored in the body, while anaemia refers to a drop in the number of red blood cells (rbcs) and/or the amount of haemoglobin within the rbcs.Cognitive learning psychology definition it typically takes several weeks after iron stores are depleted for the level of haemoglobin and production of rbcs to be affected and for anaemia to develop.Cognitive learning psychology definition there are usually few symptoms in the early stages of iron deficiency. However, as the condition worsens levels of haemoglobin and rbcs decrease, and ongoing weakness and fatigue can develop.Cognitive learning psychology definition relatively mild iron deficiency, which may cause no effects at all, is referred to as ‘iron depletion’. If a person is otherwise healthy, symptoms seldom appear before the haemoglobin in the blood drops below a certain level (100g per litre).Cognitive learning psychology definition

As the iron levels continue to be depleted further symptoms of the anaemia may develop such as shortness of breath and dizziness. If the anaemia is severe then chest pain, headaches, fast heartbeat and leg pains may occur.Cognitive learning psychology definition children may develop learning (cognitive) disabilities. Besides the general symptoms of anaemia, certain symptoms are characteristic of long-term iron deficiency.Cognitive learning psychology definition these include pica (cravings for specific substances, such as liquorice, chalk, dirt, or clay), a burning sensation in the tongue or a smooth tongue, sores at the corners of the mouth, and spoon-shaped finger- and toe-nails.Cognitive learning psychology definition

Haem-iron is the easiest form of iron for the body to absorb. It is found in meats and eggs. Non-haem iron is found in a wide variety of plants and in iron supplements.Cognitive learning psychology definition iron-rich sources include: dark green leafy vegetables (such as spinach, watercress and curly kale), iron-fortified breads, apricots, raisins, nuts and pulses (beans, peas and lentils).Cognitive learning psychology definition however, the amount of iron that is absorbed in the gut can also be altered by other substances in the diet; vitamin C can help absorbing iron while tea, coffee and foods with high levels of phytate, such as wholegrain cereals can reduce absorption.Cognitive learning psychology definition if you have been diagnosed with iron deficiency anaemia or you are pregnant or breast feeding, vitamin pills or tablets may be needed to provide extra iron.Cognitive learning psychology definition ask your doctor about the right supplement for you. In some occasions, where oral intake of iron does not improve the iron levels (eg; absorption problems) iron will be given intravenously via a drip. (through a small tube in to your arm).Cognitive learning psychology definition