IRON IN THE HUMAN BODY

Tasks and function

The human body has one Iron content of 3-5g. The daily Iron requirement is around 12-15mg. Only part of the iron supplied through food is absorbed in the gastrointestinal tract and made available to the organism. Iron is either a double positive (Fe2 +) or triple positive (Fe3 +) ion. Only the Fe2 + can be absorbed by the intestinal cells. Hence the simultaneous intake of vitamin C., which converts iron into the doubly charged form, to one better absorption. In addition, iron can be absorbed very well in heme-bound form. Heme is a molecule that is found in many proteins Iron binds - such as the red blood pigment, the hemoglobin. Animal iron, which is present in this form in high proportions, is therefore well absorbed.

Once the iron is absorbed into the intestinal cells, there are two options:
the iron can either be released into the blood via transporters and fed into the circulation. If there is already a high iron concentration in the blood, these transporters become less active and instead the iron accumulates more in stores in the cells (the Ferritin) on. Since the life span of the intestinal cells is limited, in this condition with the regular exfoliation of these intestinal cells, the iron stored in them is excreted in the stool. When iron reserves are high, many cells release more ferritin to the blood. For this reason, ferritin levels can be viewed as a rough measure of the level of iron in the body.
In the blood, iron binds to the iron transport protein transferrin. Since unbound iron is harmful to kidney and liver cells, for example, transferrin must always be present in a healthy body in order to bind the iron so that it is not free in the body. Usually about 15-45% of the iron binding sites of transferin are occupied (transferrin saturation). This value can be used to determine the body's current iron requirement. Due to the high capacity of the transferrin, even larger amounts of released iron can be intercepted without fear of damage from free iron.
People lose around 1-2 mg of iron per day. This is mainly due to dying skin and intestinal cells. Bleeding (and with it menstruation) has a major impact on iron loss, as about 0.5 mg of iron is lost with every milliliter of blood. This is one possible explanation for the fact that women are predominantly iron deficient. Apart from normal cell death, the body has no way of excreting iron. It is therefore essential that iron absorption is strictly regulated. One mechanism to reduce absorption is the release of the protein hepcidin by the liver. Hepcidin binds to iron transporters in the intestine and leads to their breakdown. A disease in which this mechanism no longer works, hereditary hemochromatosis, leads to severe iron overload in the liver and, if left untreated, liver failure.

Do you suspect iron storage disease is the cause of your problems? - Then read our article: Symptoms of hemochromatosis

The functions of iron in the body are extremely diverse. In terms of quantity, the most important task is the transport of oxygen in the blood: over half of the total iron is in the red blood pigment, hemoglobin.No other element can take on this task, since iron-containing hemoglobin quickly absorbs oxygen in the lungs, but also releases it again in the tissue.
The symptoms of iron deficiency are therefore mainly due to the reduced amount of hemoglobin and the resulting inadequate oxygen transport capacity of the blood.
In muscle tissue there is a similar protein, myoglobin, which stores oxygen and, when there is a high demand for oxygen, maintains the performance of endurance muscles and gives them their red color.
Iron also plays a crucial role in converting oxygen to carbon dioxide in the cell.
The poisonous effect of potassium cyanide is based on the blockage of an iron-containing protein, cytochrome c, which leads to internal asphyxiation.
And the most important enzymes that initiate the breakdown of endogenous and exogenous substances such as poisons and drugs also contain iron.

This article might be of interest to you: Ferritin deficiency - what's behind it?

Iron deficiency

Iron deficiency is one of the most common and clinically most important deficiency diseases. Around 30% of the world's population is affected, women around five times more often than men. The main reasons are malnutrition and increased menstrual bleeding; But also chronic intestinal diseases and blood loss through operations or injuries can trigger or worsen iron deficiency. The increased need for iron during pregnancy can also lead to iron deficiency.
Since the iron uptake of the intestine is limited, therapy is often difficult and lengthy. Iron deficiency can develop into iron deficiency anemia (anemia). The size of the red blood cells decreases and they contain less red blood pigment, so that the oxygen transport capacity of the blood decreases. The symptoms are tiredness, paleness, possibly shortness of breath and palpitations. In addition, it can lead to angular irritation (painful, often inflamed tears in the corners of the mouth), nail and hair changes.
The diagnosis of iron deficiency can be made on the basis of reduced ferritin and increased transferrin levels (the former stands for the low iron content, the latter for the high iron requirement). Iron deficiency anemia is determined by the number of red blood cells and the concentration of hemoglobin in the blood in the blood. Therapeutically, any underlying disease that leads to iron deficiency should primarily be treated and, in the long term, a diet that ensures an adequate iron supply should be maintained. Otherwise, iron can also be administered in the form of tablets or, if this is not successful, intravenously.

Further information on the subject can be found at: Iron Deficiency, How to Fix Iron Deficiency

Foods with iron

A vegan diet is a risk factor for iron deficiency. This is due to the fact that many animal foods - liver is to be mentioned here in particular - contain relatively large amounts of iron and this is mainly present as heme iron, which is well absorbed. However, many vegan foods also have a comparable iron content, so that a conscious choice of iron-rich foods can prevent iron deficiency even for vegans. Plant-based foods high in iron include grains such as whole wheat and rye, oatmeal, nuts and white beans. However, it should be noted that most of the free iron found in plants is particularly sensitive to other foods that inhibit iron absorption (such as tannins) or promote (vitamin C). Depending on the need and the promoting or inhibiting substances, iron absorption fluctuates between about 4% and 40%.

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