Role of iron in the human body


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Role of iron in the human body

  1. 1. Essential trace elements(role of iron) Eman abd el-raouf ahmed
  2. 2. The content Definition Iron Iron deficiency
  3. 3. Definition: Trace metals are metals in extremely small quantities that are present in animal and plant cells and tissue. They are a necessary part of nutrition and physiology. Ingestion of, or exposure to, excess quantities is often toxic. However, insufficient plasma or tissue levels of certain trace metals can cause pathology as well; as is the case with iron.
  4. 4. Trace metals include iron, magnesium, lithium, zinc, copper, chromium, nickel, cobalt, vanadium, ar senic, molybdenum, manganese, selenium and others.
  5. 5. Trace metals are depleted through the expenditure of energy by various metabolic processes living organisms. They are replenished in animals through diet as well as environmental exposure, and in plants through the uptake of nutrients from the soil in which the plant grows.
  6. 6. Some metals are naturally found in the body and are necessary for proper human health. Iron can help to prevent anemia, and zinc is a cofactor in over 100 enzyme reactions. All though trace metals are good for humans, in high doses they may be toxic to the body.
  7. 7. Essential trace elements are required by man in amounts ranging from 50 micrograms to 18 milligrams per day. Acting as catalytic or structural components of larger molecules, they have specific functions and are indispensable for life. Research during the past quarter of a century has identified as essential six trace elements whose functions were previously unknown. In addition to the long-known deficiencies of iron and iodine, signs of deficiency for chromium, copper, zinc, and selenium have been identified in free-living populations. Four trace elements were proved to be essential for two or more animal species during the past decade alone. Marginal or severe trace element imbalances can be considered risk factors for several diseases of public health importance, but proof of cause and effect relationships will depend on a more complete understanding of basic mechanisms of action and on better analytical procedures and functional tests to determine marginal trace element status in man.
  8. 8. Role of Iron in the Body Iron is an essential element for most life on Earth, including human beings. Iron is needed for a number of highly complex processes that continuously take place on a molecular level and that are indispensable to human life, e.g. the transportation of oxygen around your body!
  9. 9. Iron is required for the production of red blood cells (a process known as haematopoiesis), but it's also part of haemoglobin (that is the pigment of the red blood cells) binding to the oxygen and thus facilitating its transport from the lungs via the arteries to all cells throughout the body. Once the oxygen is delivered the iron (as part of haemoglobin) binds the carbon dioxide which is then transported back to the lung from where it gets exhaled. Iron is also involved in the conversion of blood sugar to energy. Metabolic energy is crucial for athletes since it allows muscles to work at their optimum during exercise or when competing
  10. 10. The production of enzymes (which play a vital role in the production of new cells, amino acids, hormones and neurotransmitters) also depends on iron, this aspect becomes crucial during the recovery process from illnesses or following strenuous exercise or competing.
  11. 11. The immune system is dependent on iron for its efficient functioning and physical and mental growth require sufficient iron levels, particularly important in childhood and pregnancy, where the developing baby solely depends on its mother's iron supplies.
  12. 12. Iron is lost by the body through a variety of ways including urination, defecation, sweating, and exfoliating of old skin cells. Bleeding contributes to further loss of iron which is why women have a higher demand for iron than men. If iron stores are low, normal haemoglobin production slows down, which means the transport of oxygen is diminished, resulting in symptoms such as fatigue, dizziness, lowered immunity or reduced ability for athletes to keep up with their training programs. Since our bodies can’t produce iron itself, we need to make sure we consume sufficient amounts of iron as part of our daily diet. Spatone, natural liquid iron supplement can provide your body’s daily absorbed iron needs whilst being extra gentle on the stomach.
  13. 13. Iron deficiency Iron deficiency (sideropenia or hypoferremia) is one of the most common of the nutritional deficiencies.[1] Iron is present in all cells in the human body, and has several vital functions. Examples include as a carrier of oxygen to the tissues from the lungs in the form of hemoglobin, as a transport medium for electrons within the cells in the form of cytochromes, and as an integral part of enzyme reactions in various tissues. Too little iron can interfere with these vital functions and lead to morbidity and death.
  14. 14. The eventual consequence of iron deficiency is iron deficiency anemia where the body's stores of iron have been depleted and the body is unable to maintain levels of haemoglobin in the blood. Children and pre-menopausal women are the groups most prone to the disease.
  15. 15. Total body iron averages approximately 3.8 g in men and 2.3 g in women. In blood plasma, iron is carried tightly bound to the protein transferrin. There are several mechanisms that control human iron metabolism and safeguard against iron deficiency. The main regulatory mechanism is situated in the gastrointestinal tract. When loss of iron is not sufficiently compensated by adequate intake of iron from the diet, a state of iron deficiency develops over time. When this state is uncorrected, it leads to iron deficiency anemia.
  16. 16. Symptoms of iron deficiency can occur even before the condition has progressed to iron deficiency anemia. Symptoms of iron deficiency are not unique to iron deficiency (i.e. not pathognomonic). Iron is needed for many enzymes to function normally, so a wide range of symptoms may eventually emerge, either as the secondary result of the anemia, or as other primary results of iron deficiency. Symptoms of iron deficiency include: fatigue dizziness pallor hair loss twitches irritability weakness pica brittle or grooved nails
  17. 17. causes chronic bleeding (haemoglobin contains iron) excessive menstrual bleeding non-menstrual bleeding bleeding from the gastrointestinal tract (ulcers, hemorrhoids, Ulcerative Colitis gastric or colonic carcinoma etc.) rarely, laryngological bleeding or from the respiratory tract inadequate intake substances (in diet or drugs) interfering with iron absorption malabsorption syndromes inflammation where it is adaptive to limit bacterial growth in infection, but is also present in many other chronic diseases such as Inflammatory bowel disease and rheumatoid arthritis blood donation Though genetic defects causing iron deficiency have been studied in rodents, there are no known genetic disorders of human iron metabolism that directly cause iron deficiency.
  18. 18. Athletics Possible reasons that athletics may contribute to lower iron levels includes mechanical hemolysis (destruction of red blood cells from physical impact), loss of iron through sweat and urine, gastrointestinal blood loss, and haematuria (presence of blood in urine).[4][5] Although small amounts of iron are excreted in sweat and urine, these losses can generally be seen as insignificant even with increased sweat and urine production, especially considering that athlete’s bodies appear to become conditioned to retain iron better.[4] Mechanical hemolysis is most likely to occur in high impact sports, especially among long distance runners who experience “foot-strike hemolysis” from the repeated impact of their feet with the ground. Exercise- induced gastrointestinal bleeding is most likely to occur in endurance athletes. Haematuria in athletes is most likely to occur in those that undergo repetitive impacts on the body, particularly affecting the feet (such as running on a hard road or Kendo) and hands (e.g.Conga or Candombe drumming). Additionally, athletes in sports that emphasize weight loss (ballet, gymnastics, marathon running, wrestling) as well as sports that emphasize high-carbohydrate, low-fat diets, may be at an increased risk for iron deficiency.
  19. 19. Diagnosis A complete blood count can reveal microcytic anemia,[6] although this is not always present - even when iron deficiency progresses to iron deficiency anaemia. Low serum ferritin *see below Low serum iron High TIBC (total iron binding capacity), although this can be raised in cases of anaemia of chronic inflammation It is possible that the fecal occult blood test might be positive, if iron deficiency is the result of gastrointestinal bleeding, although the sensitivity of the test may mean that in some cases it will be negative even with enteral blood loss As always, laboratory values have to be interpreted with the lab's reference values in mind and considering all aspects of the individual clinical situation. Serum ferritin can be elevated in inflammatory conditions and so a normal serum ferritin may not always exclude iron deficiency, and the utility is improved by taking a concurrent C reactive protein (CRP). The level of serum ferritin that is viewed as "high" depends on condition. For example, in Inflammatory bowel disease the threshold is 100, where as in chronic heart failure (CHF) the levels are 200.
  20. 20. Treatment Before commencing treatment, there should be definitive diagnosis of the underlying cause for iron deficiency. This is particularly the case in older patients, who are most susceptible to colorectal cancer and the gastrointestinal bleeding it often causes. In adults, 60% of patients with iron deficiency anemia may have underlying gastrointestinal disorders leading to chronic blood loss.[7] It is likely that the cause of the iron deficiency will need treatment as well. Upon diagnosis, the condition can be treated with iron supplements. The choice of supplement will depend upon both the severity of the condition, the required speed of improvement (e.g. if awaiting elective surgery) and the likelihood of treatment being effective (e.g. if has underlying IBD, undergoing dialysis or is having ESA therapy). Examples of oral iron that are often used are ferrous sulfate, ferrous gluconate, or amino acid chelate tablets. Recent research suggests the replacement dose of iron, at least in the elderly with iron deficiency, may be as little as 15 mg per day of elemental iron.
  21. 21. Food sources Mild iron deficiency can be prevented or corrected by eating iron-rich foods and by cooking in an iron skillet. Because iron is a requirement for most plants and animals, a wide range of foods provide iron. Good sources of dietary iron have heme-iron as this is most easily absorbed and is not inhibited by medication or other dietary components. Three examples are red meat, poultry and insects
  22. 22. Non-heme sources do contain iron, though it has reduced bioavailability. Examples are lentils, beans, leafy vegetables, pistachios, tofu, fortified bread, and fortified breakfast cereals. Iron from different foods is absorbed and processed differently by the body; for instance, iron in meat (heme iron source) is more easily absorbed than iron in grains and vegetables ("non-heme" iron source) but heme/hemoglobin from red meat has effects which may increase the likelihood of colorectal cancer.Minerals and chemicals in one type of food may also inhibit absorption of iron from another type of food eaten at the same time. For example, oxalates and phytic acid form insoluble complexes which bind iron in the gut before it can be absorbed.
  23. 23. Because iron from plant sources is less easily absorbed than the heme-bound iron of animal sources, vegetarians and vegans should have a somewhat higher total daily iron intake than those who eat meat, fish or poultry.[15] Legumes and dark-green leafy vegetables like broccoli, kale and oriental greens are especially good sources of iron for vegetarians and vegans. However, spinach and Swiss chard contain oxalates which bind iron making it almost entirely unavailable for absorption. Iron from nonheme sources is more readily absorbed if consumed with foods that contain either heme- bound iron or vitamin C. This is due to a hypothesised "meat factor" which enhances iron absorption.
  24. 24. Many medicinal herbs can offer iron boosting properties to those who suffer from iron deficiency. These medicinal properties can easily be assimilated into the bloodstream as a hot water infusion (tea). Iron enhancing herbs include yellow dock, red raspberry leaf, gentian, yellowroot, turmeric, mullein, nettle, parsley, ginseng, watercres s, and dandelion.
  25. 25. Following are two tables showing the richest foods in heme and non-heme iron.[18] In both tables, foods serving size may differ from the usual 100g quantity for relevancy reasons. Arbitrarily, the guideline is set to 18 mg, which is the USDA Recommended Dietary Allowance for women aged between 19 and 50.
  26. 26. Iron deficiency can have serious health consequences that diet may not be able to quickly correct, hence an iron supplement is often necessary if the iron deficiency has become symptomatic.
  27. 27. Bioavailability and bacterial infection Iron is needed for bacterial growth making its bioavailability an important factor in controlling infection.[20] Blood plasma as a result carries iron tightly bound to transferrin, which is taken up by cells by endocytosing transferring, thus preventing its access to bacteria.Between 15 and 20 percent of the protein content in human milk consists of lactoferrinthat binds iron. As a comparison, in cow's milk, this is only 2 percent. As a result, breast fed babies have fewer infections.Lactoferrin is also concentrated in tears, saliva and at wounds to bind iron to limit bacterial growth. Egg white contains 12% conalbumin to withhold it from bacteria that get through the egg shell (for this reason prior to antibiotics, egg white was used to treat infections)
  28. 28. To reduce bacterial growth, plasma concentrations of iron are lowered in a variety of systemic inflammatory states due to increased production of hepcidin which is mainly released by the liver in response to increased production of pro-inflammatory cytokines such as Interleukin-6. This functional iron deficiency will resolve once the source of inflammation is rectified, however if not resolved it can progress to Anaemia of Chronic Inflammation. The underlying inflammation can be caused by fever,[24] Inflammatory Bowel Disease, infections, Chronic Heart Failure (CHF), carcinomas and following surgery.
  29. 29. Reflecting this link between iron bioavailability and bacterial growth, the taking of oral iron supplements causes a relative over abundance of iron that can alter the types of bacteria that are present within the gut. There have been concerns regarding parenteral iron being administered whilst bacteremia is present, although this has not been borne out in clinical practice. A moderate iron deficiency, in contrast, can provide protection against acute infection, especially against organisms that reside within hepatocytes and macrophages such as Malaria and TB. This is mainly beneficial in regions with a high prevalence of these diseases and where standard treatment is unavailable.
  30. 30. References: .full1.1116/6/