The mineral iron forms the most important part of the oxygen capture protein hemoglobin in human blood - this protein is involved in binding with oxygen and is part of red blood cells - iron gives blood its red color. Hemoglobin carries oxygen bound in the lungs to the cells and binds with carbon dioxide again as blood flows back from the cells to the lungs for re-oxygenation. The mineral iron also forms a vital component in myoglobin - a molecule related to hemoglobin found in muscles. Myoglobin acts as the receptor and storage point for some of the oxygen found in muscle tissues. The intracellular cytochrome protein system also requires the presence of iron - this protein system is involved in energy production in the mitochondria of all cells. The average human adult body has at least 3 to 5 grams of iron in total. The liver acts as the site for storage of approximately one gram of the body's iron molecules. The iron found in red blood cells is salvaged somewhat efficiently when red blood cells undergo disintegration. The rest of the body's iron is nevertheless lost through the sweat, to hair and via the skin; iron is also lost through bleeding and through urinary and fecal excretion. Iron loss for the average healthy adult male is about one mg daily, while iron loss in healthy women is from one to two mg of iron a day. The iron lost in menstrual bleeding, through injury and bleeding, is drastically higher. Iron deficiency can have far reaching effects in the person, as iron is required in some amount by all cells in the body and all cells depend on oxygen from hemoglobin. The direct consequence of iron deficiency is anemia. In this disorder, there is a marked lowering of the total amount of circulating hemoglobin in the blood. Anemic iron loss results in the red blood cells turning very pale - they are not able to bind and transport as much oxygen as the cells normally require. Symptoms that are evident in a person affected by anemia include pallor, generalized weakness, persistent fatigue, and labored breathing on even mild exertion, symptoms like a headache, heart palpitation and persistent tiredness are also normally evident in the person. A form of a condition called pica - a perverted appetite for a (usually) non-edible item - often affects a person suffering from long term iron deficiency. People affected by such a condition can also develop an appetite for ice -pagophagia. Iron deficiency can also cause physical symptoms such as the dry scaling of lips, development of spoon nails and loss of hair. The immune system of the person suffering from iron deficiency anemia is also depressed in most cases. The ability of white blood cells to eliminate bacteria and other infective particles is also disrupted and reduced. The use of iron supplements in two groups of children affected by anemia and a depressed immunity led to an improvement in their ability to ward off infections of all kinds. The development and growth of tumors induced in test animals by means of chemical agents or viruses was also enhanced if they suffered from iron deficiency. The degeneration of the periodontal tissues in test animals is also connected to iron deficiency. Toxicity due to cadmium in animals can actually be prevented using supplements of iron in excess of nutritional requirements - this has been proven in clinical test animals. Cadmium toxicity is usually eliminated by vitamin C's protective action - this protective action of the vitamin C lies in its ability to boost the amount of iron absorbed and made available to the cells and tissues. Iron has an RDA in infants of 10 - 15 mg daily, this increases to 15 - 20 mg of iron for young children, and can be 10 - 18 mg of iron for adolescents and adults, with up to 18 mg of iron needed by pregnant and lactating women - thus the RDA requirement of different people and age groups differs. The RDA arrived at in these figure is estimated form the amount of iron that has to be ingested to account for the average daily loss of iron through various pathways in the body. The normal rate of iron loss from the body is about 1 - 2 mg per person per day. All the iron found in the dietary sources is not necessarily fully absorbed. The amount of iron absorbed from the daily diet according to nutrition scientists may account for less than ten percent of what is available in the food. As a result, to replace the losses of 2 mg at least more than 20 mg of iron must be supplied via dietary sources. At the same time, the presence of many other physical and biochemical factors can lead to an increase in the requirement for iron; some of these factors include pregnancy, the loss of blood and bleeding injury. The requirement of iron by the mother tends to continuously increase during the entire duration of a pregnancy, as the developing fetus may require a total of 300 to 500 mg of iron for development processes. This increase in iron necessary for fetal development is in addition to iron requirement of the mother - therefore, pregnant women may require supplements. In some pregnant women, iron supplements as high as 60 mg daily have sometimes been found to be inadequate in raising the total levels of hemoglobin to levels that can be considered normal for adults. The presence of high amounts of phosphates, oxalates, and phytates - which are all common compounds found in foods -can adversely affect the absorption rate of iron from dietary sources. Iron absorption is also impaired by foods like egg yolk. As far as dietary sources of iron are concerned, iron from animal sources is always absorbed better than iron from plant sources. Consuming meat may also enhance the absorption of iron from plant based foods. Acids and acidic foods also tend to increase the rate of absorption of iron from dietary sources. Iron absorption rates can also be boosted by the vitamin C (ascorbic acid) - absorption is increased as much as tenfold. Iron is abundant in foods like the various organ meats - the liver and heart, kidney etc, it is also found in high amounts in lean meats, in shellfish, and among vegetables in dried beans and fruits, in all kinds of nuts and green leafy vegetables, as well as whole grains and in blackstrap molasses. The rather poor absorption of iron used to fortify processed cereals has been suggested by some clinical studies. The iron present in human milk is absorbed five times more efficiently as is the iron found in cow's milk or baby milk formula. A well nursed baby does not require any additional iron supplements if the nursing mother has sufficient iron stores in her body. Drug stores sell different types of iron supplements in a large range of doses. Tablets of 1 mg to 60 mg or more are available in the market. These include a wide variety of supplemental forms - such as ferrous sulphate, glaciated ferrous sulphate, the ferrous fumarate, etc. At times combined with multi-vitamins, supplemental iron is also available in the form of syrup. Iron in its most absorbable form called "heme" iron, is abundant in oysters, meat and poultry as well as fish. Iron called non-heme iron is present in these foods as well; non-heme iron is found in dried fruits and molasses, in green leafy vegetables, in wine and is the form of the element present in the majority of iron supplements available in the market. Dietary sources for iron include acidic foods like tomato sauce when they are cooked in an iron pan - in this case, the cooking utensil serves to supply most of the iron. As a general rule, iron intake of non-vegetarians is generally higher than that of vegetarians. Vegetarian iron intake is also affected by another factor in that the iron they consume is at times less absorbable than iron sourced from non-vegetarian foods. A low store of iron in the body tends to affect vegetarians for this reason. The lack of iron in the diet alone is not necessarily the only cause of iron deficiency. Such deficiencies usually have an underlying causative factor, as an example, iron loss in menstrual blood, could be one reason for iron deficiency in women. Iron deficiency disorders are likely to affect women in a term of pregnancy, people who use aspirin, marathon and long distance runners as well as individuals affected with parasitic infections, long term hemorrhoids, internal ulcers, ulcerative colitis, Crohn's disease, gastrointestinal cancers or any other disorder that produces excessive blood loss or affected iron intake by malabsorption from the consumed food. Iron supplements must not be automatically used by anybody who fits any of the descriptions that define these groups of people, in fact, iron supplements are not to be taken at will even by pregnant women unless under supervision by a doctor. Various other factors can induce physical fatigue, which is the initial physical symptom of iron deficiency - to ensure that supplements are not taken at will; a doctor must always be consulted. The requirement for supplementation using iron supplements must first be assessed by a nutritionally oriented doctor, this is a very important step as the use of iron supplements when iron is not required by the body may cause harm to the body and lead to the development of unpleasant side effects in the body.
The consumption of supplements of iron becomes necessary if a nutritionally oriented doctor diagnoses that a patient is affected by iron deficiency. A daily dose of 100 mg supplemental iron is the typical adult dosage during a supplemental regimen. The cause of iron deficiency in the body must also be determined by a doctor after he or she has diagnosed that such a deficiency affects a person. Iron deficiency is normally not a serious or severe disorder - it can have simple causes such as the blood loss which occurs in normal menstrual cycles or blood donation. However, in some circumstances, the presence of iron deficiency can be a signal for the presence of ulcers or even colon cancer in the individual. Unless using iron supplements, the majority of pre-menopausal women often become marginally iron deficient due to the loss of blood as part of normal menstruation. In these cases, iron present in amounts of 18 mg in the majority of multiple-vitamin or mineral supplements is often considered enough to replenish the body's store of iron.
Fatalities can often result from huge overdoses of iron supplements - for example, a child swallowing an entire bottle of iron supplements can be lethal for him or her. For this reason, all iron containing supplements must be kept out of a reach of children at home. The excessive storage of iron in the body is apparent in disorders like hemochromatosis and hemosiderosis, as well as polycythemia and different iron loading anemias - including thalassemia and sickle cell anemia. The use of iron supplements by individuals with these disorders can be very dangerous. Iron supplements consumed in doses required to overcome an iron deficiency often induce constipation as a side effect. This can sometimes be avoided by switching the form of supplemental iron, by getting more exercise or by treating the constipation by consuming a lot of fibers and drinking a lot of fluids. When constipation occurs, the amount of iron must sometimes be correspondingly lowered. While no concrete link has been discovered, many clinical researchers have connected the presence of excessive amounts of iron in the body to pathologies like diabetes and cancer, an increased risk of infection, and diseases like systemic lupus erythematosus (SLE), it is believed to exacerbate rheumatoid arthritis and increase the chances of heart disease. The connection between high amounts of iron and these diseases have not been proven in clinical studies to date. At the same time, it is known that free radical damage in the cells is increased by the presence of too much iron; damage from free radicals can in turn cause or exacerbate many of the diseases mentioned above. As potential risk exists and no benefits may accrue, it is advisable for people not affected by an iron deficiency to use supplement iron unnecessarily. The rate of iron absorption in the body is reduced by caffeine, all high fiber foods and supplements of the mineral calcium. At the same time, the rate of iron absorption is slightly increased by vitamin C. Iron deficiency can often be treated by consuming supplemental vitamin A with supplements of iron, this is because the vitamin A aids the body in utilizing the body's store of iron in the liver - the result is a higher amount of iron in circulation within the body. A drug called deferoxamine can bind to some metals, including iron, this compound then transports the iron to different parts of the human body. The compound is therefore used in the treatment of acute iron poisoning, as well as in the treatment of chronic iron overload and in alleviating aluminum accumulation that affected people with kidney failure and related renal distress. Iron supplements must also not be used by individuals taking deferoxamine to treat an iron overload disorder; such individuals should avoid the use of all iron supplements including the amounts of iron present in many multivitamin and combination mineral supplements. The compound penicillamine also binds to metals such as copper and iron and transports them out of the body when it is excreted. There is a marked reduction in the rate of absorption and activity of penicillamine, when it is taken together with iron supplements. Reports of penicillamine induced kidney damage in at least four cases are recorded due to complete stoppage of concomitant iron therapy; these are presumably caused by a sudden increase in the rate of absorption and consequent toxic effects of excess penicillamine in the body.