How much iron does your body need?

The essential trace element iron is vital for our body. Since the body cannot produce it itself, it must be supplied through the diet. How much iron does your body need to avoid iron deficiency? Do all people have the same iron requirements or do we need more in certain phases of life?

Humans need about 1-2 mg of iron per day to compensate for the normal loss. However, due to the limited bioavailability, about ten times the amount of iron must be supplied. In addition, women of childbearing age in particular have a significantly higher loss, as they lose blood and thus iron through monthly menstruation. Accordingly, the reference values for the recommended intake are higher at this age. Together with the nutrition societies of Austria and Switzerland, the German Nutrition Society (DGE) publishes reference values for recommended iron intake. These D-A-CH reference values exist for all nutrients and are continuously updated.

Reference values of the German Nutrition Society (DGE) for recommended iron intake

More about determining iron levels in the body.

In some phases of life, humans have an increased need for iron. For women of childbearing age, indicated in the table as women aged 15 - 51, pregnant women and breastfeeding mothers, the German Nutrition Society already recommends a higher daily iron intake to prevent iron deficiency. However, growing children and adolescents, athletes and people who frequently donate blood also have an increased iron requirement.

Women of childbearing age, i.e. women who menstruate regularly, have an increased iron requirement due to the bleeding. During a normal menstruation, the blood loss is 30 - 60 ml per month, which corresponds to 15 - 30 mg of iron. In the case of cycle disorders with excessively heavy, excessively frequent or excessively long menstrual bleeding, the blood loss and thus also the iron loss can be significantly higher. The German Nutrition Society recommends a 50 % higher iron intake of 15 mg per day.

During pregnancy, approx. 30 - 40 % more blood must be produced so that the growing child is sufficiently supplied with blood and can develop properly. Additional iron is needed by the enlarged uterus and placenta, so the German Nutrition Society recommends an iron intake of 30 mg per day.

To avoid iron deficiency during pregnancy, the iron level in the blood is checked regularly as part of the preventive medical check-ups. This way, indications of an iron deficiency can be detected and treated in time. By taking iron supplements, the iron level in the blood is balanced again after a few weeks; longer-term supplementation is recommended to replenish the body's own stores. Untreated iron deficiency during pregnancy can lead to miscarriages and premature births.

Women in family planning are recommended to compensate for any existing iron deficiency before pregnancy.

Even during breastfeeding, the mother's iron requirement of 20 mg per day is still significantly increased, as the infant is supplied with iron through breast milk. It is important to determine the mother's iron status after birth, as there can be high blood losses during birth. An iron deficiency after birth, also called postpartum anaemia, is associated with postpartum depression according to current scientific knowledge [2]. Symptoms such as depressed mood, listlessness and loss of interest are not only stressful for mothers, but can also negatively influence the mother-child relationship.

Children and adolescents between the ages of 10 and 15 have an increased need for iron due to their physical development. Boys gain a lot of muscle mass during this time, which increases their total body iron stock. This is because iron is a component of the protein myoglobin, which stores and transports oxygen in muscle tissue. In girls, the onset of menstruation causes additional iron loss. The German Nutrition Society recommends an iron intake of 12 mg per day for boys and 15 mg for girls in this age group.

Iron is particularly important for healthy physical and mental development and for the immune system of children and adolescents. Especially during growth spurts, the iron store must be filled, as otherwise mental and physical growth may be delayed, in the worst case with long-term late consequences.

Athletes, especially endurance athletes, have an increased need for iron for several reasons. Firstly, iron is involved in the formation of ATP, the most important energy carrier of the metabolism. Athletes need a lot of energy, consequently a lot of ATP must also be produced. Iron is also a component of the protein myoglobin, which stores and transports oxygen in muscle tissue. The increased strain on the muscles means that more iron is consumed. In addition, excretion through the skin increases due to increased sweating. Another, usually negative influence on iron status is diet: many endurance athletes eat a high-carbohydrate diet with little meat. However, red meat in particular is a good source of iron, and animal iron is generally better absorbed by the body. Female athletes have a higher iron requirement than their male counterparts due to menstrual bleeding.

An iron deficiency in sports can cause reduced endurance performance and inexplicable drops in performance.

Donating blood is a life-saving service and helps to ensure the care of accident victims and seriously ill patients. But: with a blood donation of 500 ml, the body loses 250 mg of iron, which it makes up from its own reserves. Among other requirements for the donor, it is particularly important that the blood has a sufficiently high haemoglobin value (Hb value), because only then does the donor have sufficient own reserves for an increased formation of fully functional red blood cells. The Hb value is determined before each blood donation; the limit value is 12.5 g/dl for women and 13.5 g/dl for men. If the measured value is below the limit, the donor will not be allowed to donate that day.

With a balanced diet of meat, fish and vegetables, about 5 mg of iron can be returned to the store daily, so that the store is full again after about 50 days. According to the guideline from the Transfusion Act, a minimum interval of 56 days between two blood donations is prescribed so that the body can replicate the donated blood cells.

People lose 1-2 mg of iron per day; to compensate for the loss, they must take in 10 - 15 mg with food. Women of childbearing age, pregnant and breastfeeding women, athletes, children and adolescents as well as people who donate blood have a higher requirement. Regular monitoring of iron levels is important to counteract iron deficiency.