All cells in the body need iron (S-Fe). The majority, approximately 70%, of iron is needed for producing haemoglobin in red blood cells. In the bloodstream, iron is transported bound to a transport protein called transferrin, from which it passes to mitochondria, which supply cellular energy. Excess iron, on the other hand, is stored as ferritin (S-Ferrit).
Approximately 1–2 milligrammes of iron are lost per day through the gastrointestinal tract and with dead cells. We should get the same amount of new iron daily to replace it and maintain the balance in the body.
Iron deficiency is quite common, especially among women. Their iron intake easily remains below recommendations, and women of fertile age also lose blood with menstrual periods, for example.
Iron is obtained from food. Good sources of iron include meat, liver, blood, dried basil and oregano, and bran. Vitamin C promotes the absorption of iron from food, while coffee, tea, calcium-containing products (such as milk), and soy protein decrease its absorption. The above-mentioned beverages that interfere with the absorption of iron should therefore be avoided when eating food containing iron.
Iron balance is regulated in the small intestine. Excessive iron intake weakens the body’s defence mechanisms and increases the risk of infections. Excessive iron is particularly detrimental to the liver, pancreas, and heart. Pregnant women and those who exercise a lot should ensure an adequate level of iron.
When should iron be measured?
Checking iron levels is a good idea in connection with the following symptoms:
- Humming in the ears
- Increased heart rate
- Getting out of breath more easily than before
- Tongue pain
- Pain when swallowing
- Fragile fingernails
- Apathy, lack of interest
- Stomach pain
- Weight loss
- Missing menstrual periods
- Bloody diarrhoea
What does an iron test measure?
The iron test measures the concentration of iron in the blood bound to transferrin. Usually, iron level is tested when investigating suspicions of iron deficiency, excessive iron, and iron toxicity.
How to interpret the (S-Fe) test result?
Normally, the result is:
- 9.0–34 µmol/l
When suspecting iron deficiency, ferritin (S-Ferrit), transferrin (fS-Transf), and red blood cell size (MCV value) should also be tested.
Please contact your physician or other healthcare professional if you suspect an illness or need help interpreting the results.
Read more about defining reference values.
What can cause elevated iron levels?
The body can get an excessive amount of iron. Excessive iron levels can cause tissue damage and liver cirrhosis or liver cancer. Elevated iron levels can be caused by the following factors:
- Accelerated breaking down of red blood cells in the body
- Haemochromatosis, in which the absorption of iron through the small intestine to the body increases 3–4-fold compared to normal
- Iron toxicity
- Blood transfusion
- Hepatitis (when storage iron is released)
- Use of contraceptive pills
- High alcohol consumption
What can cause decreased iron values?
Decreased iron levels can be caused by the following factors:
- Low iron concentration in food
- Heavy menstrual periods
- Gastrointestinal ulcer
- Growth period
- Strong acceleration of red blood cell production, such as when correcting vitamin B12 deficiency
- Malabsorption (such as coeliac disease)
Iron deficiency is the most common cause of anaemia. Nutritional iron deficiency anaemia is rare nowadays, because nutrition has become more diverse. Iron deficiency emerges when blood is lost over a long time due to heavy menstrual periods or gastric or intestinal bleeding, for example.
The most typical additional S-Fe tests:
- Ferritin indicates the status of the iron reserves of the body (1395 S-Ferrit)
- Transferrin receptor, soluble, carries iron into cells and tissues (1949 S-TfR)
- Complete blood count (CBC) shows the number of red and white blood cells, number of platelets, and cell type (3696 B-TVK)
SYNLAB test list: Iron (fS-Fe, fP-Fe) https://www2.synlab.fi/laboratoriokasikirja/tutkimuskuvaukset/rauta/
Terveyskirjasto health library: Raudanpuuteanemia https://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_artikkeli=dlk00867
Terveyskirjasto health library: Anemia (alhainen hemoglobiinin) https://www.terveyskirjasto.fi/terveyskirjasto/tk.koti?p_artikkeli=dlk00006
Terveyskirjasto health library: Raudanpuute ja ravitsemus. https://www.terveyskirjasto.fi/dlk01287/raudanpuute-ja-ravitsemus?q=raudanpuute
Potilaan lääkärilehti (Patient's Medical Journal): Rautaa voi joskus saada liikaa https://www.potilaanlaakarilehti.fi/artikkelit/rautaa-voi-joskus-saada-liikaa/
Fineli: Ravintotekijät rauta https://fineli.fi/fineli/fi/elintarvikkeet?foodType=ANY&portionUnit=G&portionSize=100&sortByColumn=component&sortOrder=desc&&component=2160
Duodecim: Perinnöllinen hemokromatoosi https://www.duodecimlehti.fi/duo91463
Fasting is not required
This examination does not require fasting