Iron deficiency: New ferritin target values ​​improve diagnosis

Anemia (anemia) caused by Eisenmangel is not a rare disease

DiagnosisPrevention and treatment of iron deficiency are therefore of great importance. New target values ​​for ferritin, a protein that stores iron, are now helping with the diagnosis.

It may be surprising that even in affluent societies, deficiency symptoms still occur and become significant. This is the case with iron deficiency anemia: 1-2 percent of the adult population is affected. Pure iron deficiency without evidence of anemia (anemia) is already present in 11% of women of childbearing age and 4% of men. Undersupply can also be proven in many children and young people.

Experts cite two main reasons: changes in eating habits, with no animal protein, and iron loss as a result of blood loss, especially menstrual bleeding.

Iron is a vital mineral and a component of the red blood pigment hemoglobin, the muscle pigment myoglobin and various enzymes. It binds oxygen in the blood and muscles and transports it to the individual cells in the body. Iron is stored by the protein ferritin. The so-called transferrin, also a protein, transports the iron in the blood.

Iron deficiency limits performance

People with iron deficiency typically suffer from symptoms such as weakness, dizziness, reduced performance, headaches and irritability. But even fainting and reduced heart function are possible. Therefore, prevention, Diagnosis and Therapy of iron deficiency is of great importance.

“Our body depends on a regular supply of iron through food in order to remain efficient,” says Dr. Reinhold Lunow, internist and medical director of the Praxisklinik Bornheim between Cologne and Bonn.

"The body normally contains 3-5 g of iron, two thirds of which are found in the hemoglobin of the red blood cells, the erythrocytes. 25 mg of iron are needed daily for the formation of new erythrocytes. Normally, this requirement is covered by recycling iron from the breakdown of old erythrocytes. After blood loss, for example due to heavy menstrual bleeding, the body needs more iron for the formation of new erythrocytes than it gains from the breakdown of old erythrocytes. It then draws on the stored iron bound to ferritin in the liver, spleen and bone marrow. A significantly reduced ferritin level is therefore always an indication of iron deficiency."

Conversely, a normal or elevated ferritin level does not rule out iron deficiency. This is because ferritin is an acute phase protein that can be released in increased amounts during an inflammatory reaction, regardless of the iron concentration.

Ferritin: Reliable iron deficiency diagnosis before supplies are used up

Another problem with diagnosing iron deficiency: At the previously assumed lower ferritin concentration limit of a maximum of 12 nanograms per milliliter (ng/ml) of blood, not only are the body's iron stores already completely exhausted, meaning that treatment is already indicated. The diagnosis itself is also only possible to a limited extent at this concentration. The sensitivity, i.e. the certainty of even detecting iron deficiency, is only 59%. Dr. Lunow, an expert in diagnostics, says: "Studies have shown that with a lower target value for ferritin of 30 ng/ml, the certainty of a correct diagnosis increases to 92%. In this range, the body's iron reserves are not yet used up, so countermeasures can be taken in good time."

Iron is mainly found in meat, offal, cereals, bread, vegetables and pulses. To prevent iron deficiency, the daily iron intake through food should be 10-15 mg, depending on age and gender. However, the body only absorbs about 1-1,5 mg of this amount, mainly through the duodenum.

In addition to the menstrual bleeding mentioned above, iron deficiency can also occur during pregnancy and breastfeeding, after blood donations, with recurrent nosebleeds, an accident or an operation. The body also loses iron through ongoing internal bleeding, which often goes unnoticed, for example in the gastrointestinal tract, with tumors or with blood in the urine. In addition, iron absorption can be impaired in gastrointestinal diseases if too little stomach acid is produced.

In addition, vegetarians often suffer from iron deficiency, as iron from plant-based raw materials is less well absorbed by the intestines than from animal foods.

"Even athletes who do extreme endurance sports are at risk of iron deficiency if they like to eat a low-calorie, low-protein diet," explains internist Dr. Lunow. "In addition, extremely long runs can cause microbleeds in the intestines and bladder. Iron loss through sweat, on the other hand, only plays a minor role and is compensated for by the body itself."

In addition, there are some medications that can impair iron absorption and thus disrupt iron levels: salicylates (acetylsalicylic acid), stomach acid deacidifiers (antacids), cholesterol-lowering agents (clofibrate) and medications for treating kidney stones (ion exchangers).

Diagnosis and treatment of iron deficiency only by the Doctor

To make a reliable diagnosis, Dr. Lunow first clarifies the individual relationship between iron requirements and intake. The anamnesis also includes questions about possible causes for impaired iron absorption or excessive loss. After a simple blood test and the Laboratory examination clarity is quickly achieved. In addition to the ferritin value, other inflammatory parameters are determined, such as the value of C-reactive protein (CRP).

Although there are numerous iron preparations available in the form of tablets, effervescent tablets, capsules, drops or juice to treat iron deficiency, Dr. Lunow warns against the unauthorized and uncontrolled use of such products.

"Under no circumstances should you take iron supplements on your own and without medical supervision. They can cause gastrointestinal problems and turn your stool black. If you take too much, you even risk symptoms of poisoning with vomiting, diarrhea, circulatory collapse, bleeding, and liver and kidney damage," says Dr. Lunow. "Before taking them, you should always seek medical advice and diagnosis."

(Image: Alexander Raths/Fotolia)