Iron: an essential trace element

Iron ore, steel and bridge building, adjectives like heavy, magnetic and solid: these are the words that probably spontaneously come to mind when you think of iron. But iron is also something else, namely one of the most important essential trace elements in the human body. It is indispensable for the oxygen supply of the entire body, involved in energy metabolism and important for mental performance. It is vital for our body and must be taken in daily with food.

Iron is a chemical element with the symbol Fe, derived from the Latin word ferrum. In the periodic table, iron with atomic number 26 is in group 8, also known as the iron group. Iron has a mass fraction of 4.7 % in the earth's crust, making it the fourth most abundant element in the earth's crust. Most of the iron in the Earth's crust is associated with other elements and forms various iron minerals. Economically important are the iron oxide minerals haematite, magnetite and siderite, which are mined for steel production.

But iron is also found in food: in plant foods such as vegetables or wholemeal products, and in animal foods such as meat or eggs. Iron is also found in our bodies: 2.5 to 5 grams of the essential mineral fulfil vital functions in our bodies. More about determining iron levels in the blood.

Our body contains 2.5 to 5 grams of iron, most of which is bound to the red blood pigment haemoglobin. About one fifth of the iron is stored in the spleen and liver and is available to the body if not enough iron is taken in. A daily intake of one to two milligrams compensates for the losses. Iron transports oxygen in the blood and supplies the cells; it also plays an important role in energy production. It supports the immune system and, as a component of the CYP enzymes, plays an important role in detoxifying the body.

Learn more about the functions of iron in the body here.

Humans lose about one to two milligrams of iron per day through excretions, sweat and skin and mucous membrane cells. To compensate for the loss, a significantly higher amount must be supplied daily through food, as the absorption rate of iron is only 5 to 30 %. The German Nutrition Society (Deutsche Gesellschaft für Ernährung e. V.) gives 10 mg of iron per day for men and 15 mg for women of childbearing age as reference values. Pregnant and breastfeeding women, but also growing children and adolescents, athletes and blood donors have a higher iron requirement. From about 51 years of age, when women no longer menstruate and thus lose blood, the recommended daily amount of iron to be taken in is equal to that of men.

Find out more about your daily iron requirement here.

Haemoglobin, ferritin, transferrin - there are many values that characterise the quality of your blood. To determine an iron deficiency or iron deficiency anaemia, several blood values are determined. The Hb value indicates the concentration of haemoglobin in the blood. The ferritin value determines the storage iron. Serum iron indicates the dissolved iron in the blood. Transferrin or transferrin saturation provides information about iron transport and its utilisation in the blood. Only by looking at several values can a statement be made about the iron status in the body.

Here you can find out more about the determination of iron levels in the blood.

Iron deficiency is the reduction of total body iron; if the haemoglobin concentration in the blood falls below a threshold value, iron deficiency anaemia is present. Iron deficiency often develops insidiously and is divided into three stages depending on its severity.Iron deficiency results from increased demand, increased loss or decreased absorption of iron. Functional iron deficiency occurs as a concomitant of chronic diseases such as inflammation, infection, tumour disease, rheumatoid arthritis and heart failure.

Learn more about the development of iron deficiency here.

Iron deficiency manifests itself in a variety of symptoms that affect the outer extremities on the one hand, and the reduced energy supply in the body on the other. Cold hands and feet, damage to nails and hair are typical signs of insufficient oxygen supply to the outer extremities. Persistent fatigue, listlessness and shortness of breath during physical exertion result from the reduced energy supply. In iron deficiency anaemia, the symptoms of iron deficiency intensify, and other symptoms such as pallor, palpitations and psychological changes are added.

Learn more about the typical symptoms of iron deficiency here.

Many foods contain iron, whereby the body can utilise animal heme iron significantly better than non-heme iron from plants. Some substances promote or inhibit iron absorption. Healthy people can prevent an iron deficiency by eating a balanced mixed diet, and vegetarians and vegans can also cover their daily iron requirements with a targeted diet. If there is an increased need or if there is already an iron deficiency, it should be clarified with a specialist whether iron substitution may be necessary.

Learn more about iron deficiency nutrition here.

Numerous different iron substitutes are available in supermarkets, drugstores or pharmacies. Food supplements with a combination of different vitamins and minerals but also natural iron preparations such as microalgae or curry leaf are usually lower dosed than tablets. Iron juices are usually low-dosed and consist of iron-rich fruits; they can also be drunk as a preventive measure against iron deficiency. Highly concentrated juices are taken as a more easily digestible alternative to tablets for existing iron deficiency. In the case of severe iron deficiency or iron deficiency anaemia, intravenous iron administration is the fastest way to supply the body with the necessary iron. Because of the risk of allergic shock and overdose, intravenous iron administration is only used in special cases.

Find out more about iron substitution here.

Has this article made you curious? The linked articles will give you more information on the individual topics.