Iron: A Cure for “Pale Weakness”
Iron (= Ferrum) (Fe)
For humans – a remedy for “pale weakness”.
One of the vital elements is iron. Among all metals, iron plays the most versatile and significant role in life on Earth. It is the most abundant metal on Earth after aluminum, making up 4.2% of the weight of the Earth’s crust.
In the human body, iron is involved in hematopoiesis, oxygen metabolism, as well as in immunobiological and redox reactions.
The daily requirement for iron in the male body is about 10 mg, while the female body requires up to 20 mg (women lose 10–40 mg of iron monthly with menstrual blood). Iron deficiency can develop if the intake of this element is less than 1 mg/day. Safe iron intake in dietary nutrition is up to 45 mg/day.
Normal iron stores in the body range from 300–1000 mg for adult women and 500–1500 mg for adult men. Many people have iron reserves at the lower limit of normal. It has been proven that many healthy women have virtually no iron reserves. 57% of the iron content is in hemoglobin, 23% is found in tissues and tissue enzymes, and 20% is stored in the liver, spleen, and bone marrow.
The amount of iron in the body varies depending on weight, hemoglobin concentration, sex, and depot size. The largest depot is hemoglobin, particularly in erythrocytes. Iron reserves here vary according to body mass, sex, and hemoglobin concentration and account for approximately 57% of all iron contained in the human body. For example, a person weighing 50 kg with a blood hemoglobin concentration of 120 g/L has a heme iron content of 1.1 g.
The amount of non-heme iron stored in the form of ferritin and hemosiderin also depends on age, sex, body weight, as well as iron loss (usually from bleeding), pregnancy, or iron overload (in hemochromatosis). The tissue pool of iron includes myoglobin (a form of hemoglobin present in muscle tissue) and a small but essential fraction of iron in enzymes. Approximately 9% of iron is contained in myoglobin. There is a “labile pool” – a rapid component of recirculation that has no specific anatomical or cellular location.
Iron transport is associated with transferrin. This pathway typically transports 20–30 mg of iron per day.
Daily iron losses amount to approximately 1 mg per day. They mainly occur through the digestive tract: desquamation of epithelial cells in the intestine (0.3 mg/day), through microbleeding, and losses with bile. Iron is also consumed during the desquamation of epithelial cells in the skin and to a lesser extent with urine (less than 0.1 mg/day).
In healthy individuals, compensation for these losses occurs through the absorption of iron from food. Animal-derived food products contain iron in a more easily absorbable form. It is believed that the body absorbs up to 35% of “animal” iron. At the same time, other sources report that this figure is less than 3%.
In women, monthly iron loss occurs with menstrual blood. Quantitative analysis of iron loss related to menstruation or pregnancy is very difficult. Although menstrual blood loss in a healthy woman tends to be constant each month, differences among women are quite significant. Menstrual blood losses increase with the presence of intrauterine devices and decrease with the use of contraceptive pills.
In the human body, iron is involved in hematopoiesis, oxygen metabolism, as well as in immunobiological and redox reactions.
The daily requirement for iron in the male body is about 10 mg, while the female body requires up to 20 mg (women lose 10–40 mg of iron monthly with menstrual blood). Iron deficiency can develop if the intake of this element is less than 1 mg/day. Safe iron intake in dietary nutrition is up to 45 mg/day.
Normal iron stores in the body range from 300–1000 mg for adult women and 500–1500 mg for adult men. Many people have iron reserves at the lower limit of normal. It has been proven that many healthy women have virtually no iron reserves. 57% of the iron content is in hemoglobin, 23% is found in tissues and tissue enzymes, and 20% is stored in the liver, spleen, and bone marrow.
The amount of iron in the body varies depending on weight, hemoglobin concentration, sex, and depot size. The largest depot is hemoglobin, particularly in erythrocytes. Iron reserves here vary according to body mass, sex, and hemoglobin concentration and account for approximately 57% of all iron contained in the human body. For example, a person weighing 50 kg with a blood hemoglobin concentration of 120 g/L has a heme iron content of 1.1 g.
The amount of non-heme iron stored in the form of ferritin and hemosiderin also depends on age, sex, body weight, as well as iron loss (usually from bleeding), pregnancy, or iron overload (in hemochromatosis). The tissue pool of iron includes myoglobin (a form of hemoglobin present in muscle tissue) and a small but essential fraction of iron in enzymes. Approximately 9% of iron is contained in myoglobin. There is a “labile pool” – a rapid component of recirculation that has no specific anatomical or cellular location.
Iron transport is associated with transferrin. This pathway typically transports 20–30 mg of iron per day.
Daily iron losses amount to approximately 1 mg per day. They mainly occur through the digestive tract: desquamation of epithelial cells in the intestine (0.3 mg/day), through microbleeding, and losses with bile. Iron is also consumed during the desquamation of epithelial cells in the skin and to a lesser extent with urine (less than 0.1 mg/day).
In healthy individuals, compensation for these losses occurs through the absorption of iron from food. Animal-derived food products contain iron in a more easily absorbable form. It is believed that the body absorbs up to 35% of “animal” iron. At the same time, other sources report that this figure is less than 3%.
In women, monthly iron loss occurs with menstrual blood. Quantitative analysis of iron loss related to menstruation or pregnancy is very difficult. Although menstrual blood loss in a healthy woman tends to be constant each month, differences among women are quite significant. Menstrual blood losses increase with the presence of intrauterine devices and decrease with the use of contraceptive pills.
Biological role in the human body. Iron is a component of the most important iron-containing proteins, including enzymes, in which it is present both in heme form and in non-heme form. The majority of iron in heme form is included in hemoglobin. Additionally, iron in the same form is part of cytochrome P-450, cytochrome G5, mitochondrial respiratory chain cytochromes, and antioxidant enzymes (catalase, myeloperoxidase). Therefore, this macroelement is important not only for supplying the body with oxygen but also for the functioning of the respiratory chain and ATP synthesis, metabolism and detoxification of endogenous and exogenous substances, DNA synthesis, and inactivation of toxic peroxide compounds.
Thus, the most important functions of iron in the body are the production of hemoglobin and myoglobin and the enrichment of erythrocytes with oxygen.
How does iron “work” in the human body? The human body is permeated with tiny vessels – capillaries. Most of them are so thin that erythrocytes have to transform from a sphere into a thin rod to squeeze inside. Despite the long and difficult journey through the large circulation – from the left ventricle to the right atrium – some erythrocytes spend less than 30 seconds on the run, and during this time they must manage to deliver oxygen to the tissues. In the capillaries of the lungs, erythrocytes pass through in just 10 seconds, managing to release the CO2 they have captured in the body’s tissues and replace it with a new portion of O2.
Erythrocytes would not be so agile if it were not for hemoglobin. The globin protein, which forms its basis, has the appearance of a sphere made up of four subunits – polypeptide chains folded into pockets. Each of these pockets contains an iron-containing complex – heme. As soon as one molecule of O2 penetrates the pocket and binds to iron, the other globin chains begin to twist sequentially in such a way that the second, third, and fourth iron atoms “stick out” outward. Here, iron instantly binds with oxygen, which in the lungs is almost as abundant as in the surrounding air, that is, relatively plentiful. Due to the rearrangement of the globin molecule, the so-called cooperative effect arises: the binding of the first globin subunit with oxygen increases the affinity of the second subunit for it, the binding of the second increases the affinity of the third, and so on. With each step, the attachment of O2 to the iron of hemoglobin becomes easier. Thus, the fourth iron atom acquires 500 times more affinity for oxygen than the first. This mechanism was established by British biochemist and Nobel laureate Max Perutz in the 1960s.
Thus, hemoglobin becomes saturated with oxygen without forming a strong chemical bond with it and is 100% converted into bright red oxyhemoglobin, which is typical for arterial blood. In the capillaries, where the concentration of O2 is lower than in the arteries, the stability of oxyhemoglobin decreases. Danish physiologist Christian Bohr, father of the famous Niels Bohr, established that not only does a high concentration of carbon dioxide displace oxygen from hemoglobin, but the binding of each CO2 molecule to an iron atom reduces the affinity of neighboring atoms for O2, meaning there is a competition between two cooperative systems. As a result, hemoglobin very quickly delivers all the oxygen to the tissues and becomes saturated with carbon dioxide, changing color to a darker shade – the color of venous blood.
Hemoglobin is synthesized where young erythrocytes are born – in the bone marrow. One erythrocyte contains 400 million hemoglobin molecules, and the bone marrow produces 2.5 million erythrocytes every second! However, 70% of the total iron in the body, or about 0.8–0.9 g, is sufficient to saturate the blood with hemoglobin at a rate of 160 g/L.
The lifespan of an erythrocyte is short – only 125 days. In the “graveyard” of erythrocytes, in the spleen, hemoglobin breaks down, and it needs to be rebuilt. Iron from destroyed erythrocytes is largely returned to the site of synthesis, therefore the daily iron requirement for a healthy person does not exceed 10–20 mg.
Iron is also necessary for increasing the activity of many enzymes, for growth processes, energy production, and maintaining the normal state of the immune system.
Iron-containing compounds play an important role in the functioning of the immune system, primarily the cellular component. The most obvious manifestation of iron deficiency is iron deficiency anemia, which can be associated with serious disorders in the body (chronic blood loss from internal bleeding).
Thus, the most important functions of iron in the body are the production of hemoglobin and myoglobin and the enrichment of erythrocytes with oxygen.
How does iron “work” in the human body? The human body is permeated with tiny vessels – capillaries. Most of them are so thin that erythrocytes have to transform from a sphere into a thin rod to squeeze inside. Despite the long and difficult journey through the large circulation – from the left ventricle to the right atrium – some erythrocytes spend less than 30 seconds on the run, and during this time they must manage to deliver oxygen to the tissues. In the capillaries of the lungs, erythrocytes pass through in just 10 seconds, managing to release the CO2 they have captured in the body’s tissues and replace it with a new portion of O2.
Erythrocytes would not be so agile if it were not for hemoglobin. The globin protein, which forms its basis, has the appearance of a sphere made up of four subunits – polypeptide chains folded into pockets. Each of these pockets contains an iron-containing complex – heme. As soon as one molecule of O2 penetrates the pocket and binds to iron, the other globin chains begin to twist sequentially in such a way that the second, third, and fourth iron atoms “stick out” outward. Here, iron instantly binds with oxygen, which in the lungs is almost as abundant as in the surrounding air, that is, relatively plentiful. Due to the rearrangement of the globin molecule, the so-called cooperative effect arises: the binding of the first globin subunit with oxygen increases the affinity of the second subunit for it, the binding of the second increases the affinity of the third, and so on. With each step, the attachment of O2 to the iron of hemoglobin becomes easier. Thus, the fourth iron atom acquires 500 times more affinity for oxygen than the first. This mechanism was established by British biochemist and Nobel laureate Max Perutz in the 1960s.
Thus, hemoglobin becomes saturated with oxygen without forming a strong chemical bond with it and is 100% converted into bright red oxyhemoglobin, which is typical for arterial blood. In the capillaries, where the concentration of O2 is lower than in the arteries, the stability of oxyhemoglobin decreases. Danish physiologist Christian Bohr, father of the famous Niels Bohr, established that not only does a high concentration of carbon dioxide displace oxygen from hemoglobin, but the binding of each CO2 molecule to an iron atom reduces the affinity of neighboring atoms for O2, meaning there is a competition between two cooperative systems. As a result, hemoglobin very quickly delivers all the oxygen to the tissues and becomes saturated with carbon dioxide, changing color to a darker shade – the color of venous blood.
Hemoglobin is synthesized where young erythrocytes are born – in the bone marrow. One erythrocyte contains 400 million hemoglobin molecules, and the bone marrow produces 2.5 million erythrocytes every second! However, 70% of the total iron in the body, or about 0.8–0.9 g, is sufficient to saturate the blood with hemoglobin at a rate of 160 g/L.
The lifespan of an erythrocyte is short – only 125 days. In the “graveyard” of erythrocytes, in the spleen, hemoglobin breaks down, and it needs to be rebuilt. Iron from destroyed erythrocytes is largely returned to the site of synthesis, therefore the daily iron requirement for a healthy person does not exceed 10–20 mg.
Iron is also necessary for increasing the activity of many enzymes, for growth processes, energy production, and maintaining the normal state of the immune system.
Iron-containing compounds play an important role in the functioning of the immune system, primarily the cellular component. The most obvious manifestation of iron deficiency is iron deficiency anemia, which can be associated with serious disorders in the body (chronic blood loss from internal bleeding).
Iron synergists and antagonists. Calcium promotes the absorption of iron, except in cases where calcium doses are very high.
In the form of chelating compounds, iron can act as a synergist of chromium.
In the form of chelating compounds, iron can act as a synergist of chromium.
Phosphates found in eggs, cheese, and milk, oxalates, phytates, and tannins contained in black tea, bran, and coffee hinder the absorption of iron.
Vitamin E and zinc in high concentrations reduce iron absorption. Coffee, dark leafy vegetables, as well as vitamin A deficiency can decrease the body’s ability to absorb iron.
Vitamins C, B6, B12, gastric acid, pepsin, and copper promote iron absorption, especially when derived from animal sources.
Decreased acidity of gastric juice due to prolonged use of antacids or acid-reducing medications (such as Zantac, Tagamet, Pepcid, Askid) is accompanied by a reduction in iron absorption.
Excess iron reduces the body’s ability to absorb copper and zinc.
Vitamin E and zinc in high concentrations reduce iron absorption. Coffee, dark leafy vegetables, as well as vitamin A deficiency can decrease the body’s ability to absorb iron.
Vitamins C, B6, B12, gastric acid, pepsin, and copper promote iron absorption, especially when derived from animal sources.
Decreased acidity of gastric juice due to prolonged use of antacids or acid-reducing medications (such as Zantac, Tagamet, Pepcid, Askid) is accompanied by a reduction in iron absorption.
Excess iron reduces the body’s ability to absorb copper and zinc.
Iron deficiency is most often due to impaired absorption and assimilation, and can also result from intestinal bleeding, excessive blood loss during menstruation, a diet high in phosphorus, digestive disorders, prolonged illnesses, ulcerative lesions, prolonged use of antacid medications, excessive consumption of coffee or tea, and other causes.
Excessive physical exercise and heavy sweating increase the excretion of iron from the body.
Excessive physical exercise and heavy sweating increase the excretion of iron from the body.
Signs of iron deficiency: anemia, pallor of the skin, injection of scleral vessels, brittleness and loss of hair, gray hair, nail detachment, nails in the shape of spoons, difficulty swallowing, inflammation of the oral mucosa, digestive disorders, dizziness, weakness, fatigue, nervousness, slowed mental reactions, brittle bones, obesity.
Iron deficiency anemia accounts for 80% of all anemias. From the 6th to the 16th century, that is, almost all of the Middle Ages, anemia was considered particularly characteristic of young girls and was called “pale weakness.” With the development of medical chemistry, its cause was established – iron deficiency in the blood, and the disease was named “chlorosis,” from the Greek word meaning pale-green color. Both names highlight the externally noticeable symptom of the disease. Today, the disease is called iron deficiency or hypochromic anemia.
In cases of insufficient iron intake into the body, iron-containing medications are used. For this purpose, even ordinary iron filings were previously used. From history, it is known that Count A.P. Bestuzhev-Ryumin (1693–1766) proposed drops (which became known as “Bestuzhev’s”) as a strengthening and stimulating agent, which were a solution of iron(III) chloride in a mixture of ethanol and ethyl ether.
Iron deficiency anemia accounts for 80% of all anemias. From the 6th to the 16th century, that is, almost all of the Middle Ages, anemia was considered particularly characteristic of young girls and was called “pale weakness.” With the development of medical chemistry, its cause was established – iron deficiency in the blood, and the disease was named “chlorosis,” from the Greek word meaning pale-green color. Both names highlight the externally noticeable symptom of the disease. Today, the disease is called iron deficiency or hypochromic anemia.
In cases of insufficient iron intake into the body, iron-containing medications are used. For this purpose, even ordinary iron filings were previously used. From history, it is known that Count A.P. Bestuzhev-Ryumin (1693–1766) proposed drops (which became known as “Bestuzhev’s”) as a strengthening and stimulating agent, which were a solution of iron(III) chloride in a mixture of ethanol and ethyl ether.
Iron excess in tissues and organs contributes to increased production of free radicals and increases the body’s need for vitamin E.
Elevated iron levels may also precede the development of heart diseases and malignant tumors.
Iron deposits in tissues lead to hemochromatosis; hereditary disorders of iron metabolism associated with its excess can cause bronze pigmentation of the skin; liver cirrhosis, diabetes, and heart diseases may also develop.
In workers of iron mines, a disease called siderosis of the lungs may occur, characterized by bronchitis, early emphysema, and dry pleurisy. Among welders, inflammatory diseases of the nasal mucosa and nasopharynx are observed.
When using iron for therapeutic purposes, side effects may occur, related to the development of constipation due to iron binding with hydrogen sulfide, which weakens intestinal motility.
Elevated iron levels may also precede the development of heart diseases and malignant tumors.
Iron deposits in tissues lead to hemochromatosis; hereditary disorders of iron metabolism associated with its excess can cause bronze pigmentation of the skin; liver cirrhosis, diabetes, and heart diseases may also develop.
In workers of iron mines, a disease called siderosis of the lungs may occur, characterized by bronchitis, early emphysema, and dry pleurisy. Among welders, inflammatory diseases of the nasal mucosa and nasopharynx are observed.
When using iron for therapeutic purposes, side effects may occur, related to the development of constipation due to iron binding with hydrogen sulfide, which weakens intestinal motility.
Iron is necessary: for children during growth, for pregnant women and nursing mothers, for young girls and women whose iron balance is under stress due to menstruation, for athletes who lose minerals due to sweating.
Dietary sources of iron: eggs, fish, liver, meat (especially veal), ham; molasses, brewer’s yeast; black bread; vegetables: potatoes, kelp (seaweed), beets, asparagus, Jerusalem artichoke, pumpkin, horseradish; green leafy vegetables; herbs: basil, coriander (cilantro), green onion, leek, chives, parsley, arugula, celery leaves, dill, garlic greens, spinach, sorrel; legumes: beans, peas, soybeans, beans, lentils; grains: buckwheat, corn, oats, millet, soft wheat, hard wheat, brown unpolished rice, wild rice, rye, barley, wheat and rice bran, whole grains; nuts and seeds: peanuts, cashews, sesame, poppy, macadamia, almonds, Brazil nuts, walnuts, pine nuts, sunflower seeds, pumpkin seeds, pistachios, hazelnuts; dried fruits: raisins, dried figs, dried apricots, dates, prunes; fruits: avocado, quince, cherry plum, grapes, pears, viburnum, cornelian cherry, raspberries, sea buckthorn, peaches, black chokeberry, black currants, persimmon, mulberries, apples; vegetable oils: pumpkin seed oil.