The role of iron in the body and its homeostasis - Dissertation Example

? Role of Iron in the Body and its Homeostasis Role of Iron in the Body and its Homeostasis Iron is an important nutrient that is required for several biochemical processes. It is also a component of various elements of the body such as hemoglobin and myoglobin. Iron is usually toxic when in excess and therefore its consumption should be regulated. This paper will try to describe what iron is in chemotherapy or in biology. This description will be biological in nature. The description will include the elements of iron and its basic properties and also the roles of iron in the body. The paper will also describe the roles of iron in the body, what it does and how it does it and also describe the various elements that help iron in its functioning. The paper will look into detail the absorption process of iron in the body and this will include how iron is absorbed and which forms of iron are absorbed in the body. This will include a detailed description of the entire absorption process. The homeostasis of iron will also be described in detail, and include the importance of iron in anemia or rather how lack of iron is affecting the body and causing anemia. Finally, this discourse will describe the limitations of having too much iron the body or in the blood and the various disorders or diseases that may result due to too much iron in the body. The paper will have an abstract which describes what the paper is about, the introduction which will describe briefly the topic in question, the main body which describes the various elements of iron and its roles and functions together with the absorption process and homeostasis, and finally the conclusion which will summarize what has been discussed in the paper and give the views. Introduction Iron is both a chemical element and a metal. It is the most common element that is found both in the inner and outer core of the earth. Iron exists in different states of oxidation and it occurs in environments with low oxygen rates. Iron plays an important role in biology in that it forms complex structures with oxygen in hemoglobin and myoglobin (Williams 2011, p. 56). Hemoglobin is a protein which contains iron and is used in transporting oxygen. It is found in the red blood cells in all vertebrates apart from the fish family. It is used to carry oxygen from the lungs to the rest of the body to help in providing energy to nutrients that are burnt up so that the organism can function effectively. In mammals, hemoglobin makes up almost all of the red blood cells. It also carries other gasses apart from oxygen such as carbon dioxide and nitric oxide, and it is also found outside red blood cells. Myoglobin is a protein which has iron and is oxygen binding. It is found in the tissue of vertebrates. Myoglobin is not found in the blood unless it is released when a muscle is injured. It has a single chain protein with eight alpha helices with a hydrophobic core. Iron is found in all living things including human beings (Williams 2011, p. 79). The color of the blood is usually characterized with the amount of hemoglobin in the blood. The hemoglobin is a protein which contains iron. Iron is usually bound to cofactors such as the hemes. Enzymes and proteins which contain iron usually take part in many biological oxidations and transportation processes. Iron is very pervasive and it is found in various diets or foods such as red meat, lentils, beans and fish. These foods contain high amounts of iron. It can, however, be found in low amounts in molasses and teff. Iron in meat is usually more easily absorbed than iron in vegetables. Iron provided by foods or dietary supplements is usually found as iron fumarate. This is an iron salt of fumaric acid which appears as a reddish powder used as a supplement in the intake of iron (Williams 2011, p. 109). Iron sulphate is usually cheaper and easily absorbed as compared to fumaric iron. Elemental iron which is also known as reduced iron is usually absorbed at a higher efficiency and often added to foods such as cereals. Iron can be chelated to amino acids and this is the instance when it is mostly available to the body. In the body cells and red blood cells, the iron storage is usually regulated. The protein transferring usually binds iron ions that are absorbed from the duodenum and carries them in the blood and distributes it to the cells (Andrews 1999, p. 31). The distribution of iron is mostly regulated in mammals. This is because irons are toxic when absorbed in large numbers and therefore can be harmful to organisms especially human beings. The uptake of iron is highly regulated in the body even though it has no means of secreting excess iron. Small amounts of iron are usually lost on a daily basis as a result of cell sloughing in the mucosal and epithelial skin and large amounts are lost through the regulation process (Andrews 1999, p. 67). Iron is an absolute requirement for most forms of living things including bacteria. The toxic nature of iron comes about when it catalyzes the conversion of hydrogen peroxide into radicals which can cause damage to cellular structures, and in the end kill the cell. To prevent such damage, the organisms usually bind the iron atoms to proteins. The most important group of proteins that take part in iron binding is the hemes which contain iron at their centers (Andrews 1999, p. 85). Human beings usually use different types of hemes to carry out redox reactions. These reactions are usually important for oxidative processes which are the main source of energy for the cells. Body iron stores Most people who eat well and are well nourished usually have about four to five grams of iron in their system. Only 2.5 grams are usually found in the hemoglobin that is needed to carry oxygen through the blood to most body parts (Fleming 2005, p. 123). The rest is usually found in ferritin complexes that are present in all cells but most commonly found in the bone marrow and liver. The liver stores a lot of ferritin and is the main source of iron reserve in the body and is usually lower in women because they use the iron a lot to replace the ones lost during menstruation and pregnancy. About four hundred grams of the total iron content found in the body is devoted to cellular proteins that use iron for important cellular processes such as transportation and storage of oxygen and energy producing reactions such as redox (Fleming 2005, p. 134). When there is little iron in the body, the storage centers of iron in the body will be the first to be attacked. The attack of these stores usually has no symptoms although some scientists have argued that it has symptoms even though vague and not specific. The dietary iron usually has several sources which include the animal sources, the vegetable sources and the supplements. The iron found in meat is known as the heme iron. It is the iron that is derived from the hemoglobin in the blood of animals. It is more readily absorbed as compared to other iron types which are not heme. The non heme irons are found in plants or vegetables. Vegetables have iron which is non heme because they do not have any hemoglobin in them. The various supplements from which you can acquire iron include the ferrous gluconate, the ferrous sulphate which is the most usual form and the most affordable way to take supplements of iron, ferrous fumarate and the spirulina which facilitates the absorption of iron and this is usually the main reason why it is added to some supplements to help in quick absorption (Fleming 2005, p. 163). Iron is the main atom for the heme group because it is the metal that binds molecular oxygen in the lungs and carries it to all of the other cells in the body that need oxygen for their survival and their functionality. If there existed a heme group without iron in it, then living organisms would not exist because there would be no site for oxygen to bind with proteins, and hence no oxygen would be delivered to the cells. Iron has been to known to be important in the functioning of red blood cells. Although it is usually obtained from a wide variety of foods and supplements, it still has a deficiency and its deficiency is the most known form of mineral deficiency. Iron levels in the blood should not be too much or too little. Too much of something is usually dangerous and this is not an exception for iron; and hence at any given point of time, there should be an optimal level of iron in the blood to avoid either a deficiency or an overload. A deficiency is where there is little iron in the blood or in the body and an overload is where there is too much iron in the blood. Excessive intake of ingested iron can therefore cause excessive levels of iron in the blood which could be harmful to the cells especially the ones around the heart and the liver. Too much iron contains too much ferrous components which will react with peroxides to produce radicals that are very sensitive due to the fact that they easily react with other chemicals (Fleming 2005, p. 210). The reactions can cause damage to proteins and other cellular components. Overconsumption of iron is usually a result of people taking too much iron tablets that contain too much ferrous compounds, for example, most children usually take ferrous tablets that are prescribed for adults or they take dosage that is meant for adults. This will lead to too much ferrous intake in the form of iron and may cause a lot of damage to the human being or to any other living organism. Role of iron in the body When dealing with iron in the body, a person has to ask oneself what role iron plays in the body. Iron has several roles and functions in the body but the main role that it plays is binding with hemoglobin which is the protein in the red blood cell so that it can help in the carrying of oxygen from the lungs to other parts of the body. Iron is needed for several processes in the body that are very complex and that take place on a molecular level, and that are indispensable to human life. Example of such processes is transportation of oxygen around the body. One of the roles of iron in the body is that it is required for the production of red blood cells. Iron is also part of the hemoglobin that binds to the oxygen and hence facilitates its transport from the lungs through the arteries to all the cells in all the parts of the body. Once the oxygen has reached its destination, the iron as part of the hemoglobin still binds to carbon dioxide and transports it through the veins back to the lungs where it can be removed from the body to give room for more oxygen (Conor 2004, p. 122). Another role of iron is that it can also be involved in the conversion of blood sugar to energy. Body cells and tissues need a lot of energy to carry out their functions and this energy is usually derived from blood sugars. The blood sugars are converted into energy with the use or help of iron. Metabolic energy is very important for athletes because it gives muscles room to work at their best level during exercise or when competing. Athletes therefore need a lot of energy in the body and iron plays an important role in the manufacture of that energy. The production of enzymes in the body also depends on iron. Enzymes are important in the body because they help in the production of new cells, amino acids, hormones and neurotransmitters. Enzymes are important when someone is recovering from an illness or following a very strenuous exercise or competition and therefore iron is also very vital in this process since it helps in the production of enzymes. Another role of iron is in the immune system. The immune system is the system that protects the body from illness or any pathogens that may infect it. The immune system is dependent on iron in order to function effectively and efficiently. The body is also dependent on iron for both physical and mental growth. This is very important for child development during pregnancy and after birth for child growth and development. The developing baby whether in the womb or after birth depends primarily on the irons of the mother especially through breastfeeding when the baby has been born and it cannot eat any solid foods or any foods that contain iron or iron components. Small children are, however, usually given iron supplements to boost the levels of iron in their bodies so as to avoid iron deficiency. Functions of iron Apart from the roles that iron plays in the body it has several special functions and they are underlined below: It helps in preventing and curing anemia which is caused by lack of iron in the body; It is also important in the production of hemoglobin in the blood with the help of vitamin C, copper and manganese for absorption purposes; Iron helps in growth because it ensures that the cells get enough oxygen to enable them stay alive and grow; Iron helps in the synthesis of proteins; It also helps in creating energy and fighting infection, and hence it leads to healthy skin and hair. Iron deficiency This is the most common sign of low iron blood levels. It usually leads to lack of energy which is also referred to as anemia. Iron deficiency is a condition resulting from too little iron in the body. It is the leading cause of anemia worldwide. The term anemia, iron deficiency and iron deficiency anemia can all be used to mean the same thing and hence they are usually used interchangeably. Iron deficiency has different categories from iron stores which have totally been depleted and have no functional or health impairment to iron deficiency with anemia which usually has an effect to the functioning of several organ systems (Conor 2004, p. 225). We should be concerned about iron deficiency because it can delay the development of an infant by limiting normal activity and movement of the infant or even the mental ability. We should also be concerned because iron deficiency anemia can lead to small or early babies which are underdeveloped. These babies are not healthy or normal and they are likely to have several health problems. Iron deficiency can also lead to fatigue. Fatigue is bad because it impairs the ability to do physical work in adults. Causes of iron deficiency The factors that cause iron deficiency fall into two broad categories namely the increased iron needs and the decreased iron intake or absorption. Increased iron needs The body may be experiencing certain conditions that may result to increase in the need of iron which might not be available at that particular time. Most of the people who need additional or extra iron are usually infants, toddlers, women, teenagers and athletes. Infants and toddlers grow rapidly if they are healthy. Because of their rapid growth, they usually need more or extra iron as compared to older children. This is because the body uses a lot of energy in the growth process and hence the increased need of iron usually causes iron deficiency since the body uses too much iron in producing energy. Women who are pregnant also need higher levels of iron than a normal woman. This is because they use a lot of energy and they also share their iron with the developing babies. People who lose blood usually lose a lot of iron and they therefore need higher levels of iron. They usually need extra iron to replace what they have lost through the blood. Decreased iron intake or absorption This means that there is not enough iron being taken into the body. The decreased iron intake usually depends with the rate of absorption of iron in the body, for instance, iron that is found in meat, poultry or fish is absorbed twice more than that found in plants. The amount of iron that is absorbed from plants usually depends on the other types of foods that are eaten at the same meal. Foods that contain the heme iron usually enhance the absorption from food substances that do not have the heme iron, and therefore it is advisable to take vegetables and meat together for the enhancement purposes. The people who are more at risk due to iron deficiency are the young children and the pregnant women because of the rapid growth in young children and the high needs of iron in pregnant women. Adolescent girls and women are also at risk because of menstruation. In young children, iron deficiency is experienced mostly between six months and three years of age because of the increased growth and poor intake of dietary iron. The infants and children who are at risk are those that are born early or small, those who are fed with cow milk before they reach one year of age, and children who have special health needs, like those with chronic infections or restricted diets. Signs and symptoms of iron deficiency Too little functions can lead to the impairment of body functions. Most physical signs and symptoms usually do not show up unless iron deficiency anemia occurs. Some of the signs and symptoms of iron deficiency include: Feeling fatigued and weak; Decrease in performance either at work or at school; Slow development process in children; Irregular body temperatures all the time; Decrease in the functioning of the immune system which increases the chances of infection; Inflammation on the tongue; Iron deficiency can be detected by a doctor by carrying out several tests such as the blood test to specifically screen for iron deficiency. The most common tests used in the screening process are the hemoglobin test which measures the level of hemoglobin in the blood and the hematocrit test which measures the amount of red blood cells in the blood (Carol 2008, p. 116). These tests will show how much iron is in the body. Other tests that are used to confirm that the cause of anemia is indeed iron deficiency include complete blood count which helps in identifying the number and volume of the red blood cells, serum ferritin which measures the amount of stored iron, serum iron which measure the amount of iron in the blood, transferring saturation which measures the transported form of iron, and transferring receptor which measures the level of increased red blood cell production (Carol 2008, p. 121). Iron deficiency is usually treated depending on certain factors such as age, health and causes of the deficiency; for example, if the doctor thinks that the deficiency is caused by increased iron needs in the body, then he may prescribe an iron supplement before having any tests done. If the deficiency is caused by a low diet of iron, then a patient may be asked to eat more iron rich foods or diet. In order to prevent iron deficiency, it is advisable that one has to eat a healthy diet that is full of iron or has a good iron source. One may also eat foods that will enhance the absorption of iron in the body from other sources of iron. Iron overload This is the accumulation of extra iron in the body tissues. Iron overload leads to a disease called hemochromatosis which has both genetic and non-genetic causes. The body can substantially reduce the amount of iron that it absorbs across the mucosa even though it does not shut down the entire transport process. Overload can also occur when there is excess iron in the lining of the intestine when children eat a lot of iron tablets. The iron from the tablets is usually absorbed in the blood stream and cause a deadly syndrome called iron intoxication (Carol 2008, p. 121). Large amounts of iron in the body may also lead to damage to cells in the liver or heart. The body is able to control or regulate the intake of iron especially when it is in excess. Iron toxicity is therefore usually a result of ingestion of extraordinary substances such as overdose of iron tablets and not necessarily from the changes in the diet. Acute toxicity is very dangerous to the body as it causes more damage especially to the intestinal walls and the mucosal walls. When the iron toxicity is very chronic, it means that there is more chronic iron overload syndrome which is usually not normal in that it is caused by a genetic disease, repeated transfusions or other causes (Insel 2010, p. 312). When the iron overload is chronic, the iron stores in adults may reach fifty grams which is ten times the normal total body iron or even more than that. Iron overload can however be regulated by watching the levels of iron foods that are being taken into the system or limiting the use of iron supplements and iron tablets which might lead to too much iron in the body and which might further lead to diseases such as hemochromatosis. The absorption process The absorption of dietary iron is a process which varies due to many factors and it changes with different factors. The amount of iron which is taken in the body is usually more as compared to that which is absorbed. The amount of iron absorbed varies depending on different circumstances and the type of iron being absorbed. The absorption of dietary iron from supplements usually vary with the needs of iron in the body and is usually between ten and twenty percent of the total iron intake (World Health Organization 2004, p. 35). Absorption of iron from animal products such as meat is the best known absorption method of iron. It is very efficient allowing absorption of between fifteen and thirty five percent of intake into the body (World Health Organization 2004, p. 36). Heme iron is present in the proteins which is found in animal products while heme iron is found in mitochondria in all cells that use oxygen for breathing. Most of the mineral nutrients that are absorbed from digested food or supplements is usually absorbed in the duodenum by the enterocytes found in the lining of the duodenum. These cells have molecules which are specially designed to enable them move into the body. Dietary iron can therefore be absorbed as part of protein such as the heme protein which is ferrous in nature. A ferric enzyme reduces ferric three into ferric two. The divalent metal transporter then transports all kinds of divalent metals into the body and then it also transports the iron across the cell membrane of the enterocyte into the cell (Insel 2010, p. 315). The lining cells of the intestines can then store the iron as ferritin which will be accomplished by ferric three binding itself to a poferritin or the cell can transport it into the body by the help of a protein called ferroportin. The rates at which our bodies absorb iron usually respond to certain factors which are interdependent such as iron stores, the extent of production of red blood cells in the bone marrow, the level of concentration of hemoglobin in the blood and the level of oxygen in the blood. Adults absorb between one and two milligrams of iron everyday from the diet to compensate the iron which is lost through sweat, blood loss and other forms of iron loss. Iron usually passes through the apical and basolateral membranes for the epithelial cells which are highly absorptive so that they can reach the blood (World Health Organization 2004, p. 52). When it reaches the blood, it is incorporated in the proteins that transport iron. The non heme iron is usually transported via the divalent metal transfer. Homeostasis of iron Homeostasis in biology means the process of maintaining an internal equilibrium in the body to enable it to adjust itself physiologically when responding to external stimuli or external environmental changes. The main function of homeostasis is to keep all the body processes stable when there are variations in the outside environment (Sareen 2008, p. 78). Homeostasis is the reason why human beings can function well in different weather conditions; for example, they can function well in both hot and cold environments. Animals and human beings can maintain their internal body temperatures even though exposed to cold temperatures. These animals and human beings are called homeotherms. The process of homeostasis involves regulation of the blood pressure, temperature, blood sugar levels, hormone levels and enzyme levels in the human body or in the bodies of all the other mammals (Sareen 2008, p. 89). The organs which play an important role in the homeostasis process are the liver, kidneys and the brain. The kidneys are responsible for the control of the level of blood water and regulation of the salt and iron content in the blood. The liver is responsible for ensuring that metabolism of carbohydrates is stable and that toxic substances in the body have been rid off. The brain, on the other hand, helps in controlling the nervous system and the endocrine system which are very important in retaining homeostasis. The most important element of homeostasis is regulation of temperature. Our bodies are able to maintain a constant body temperature most of the time because of the process of homeostasis, for instance, when people sweat when it is hot or shiver when it is cold, there is a homeostasis process that is going on in the body that enables them to maintain a constant body temperature. Iron has a role in the homeostasis process. Iron is responsible for transporting oxygen from the lungs to all the parts of the body. Oxygen is usually used to generate energy and heat which will ensure that the temperature of the body is regulated. Conclusion The major role of iron in the body is mainly to produce hemoglobin which is very important for our bodies. Human beings should have a dose of more than one milligram of iron every day in order to ensure that there is no iron deficiency which can lead to anemia or iron overload which might lead to hemochromatosis References Andrews N, 1999 December 23. Disorders of Iron Metabolism. New England Journal of Medicine. Carol J 2008. 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