What is iron and why is it important?
Iron is a mineral that the body needs to produce haemoglobin, the protein in red blood cells that transports oxygen from the lungs to the body’s tissues. Iron is also needed for energy metabolism, normal blood formation and several important functions in the body.
This iron deficiency test measures P-Iron, also known as plasma iron or Fe. The analysis shows the amount of iron in the blood at the time of sampling and can indicate whether your iron levels are low or elevated. Since P-Iron can vary during the day, the sample should be taken in the morning and interpreted together with symptoms and preferably other iron markers, such as ferritin and transferrin saturation, for a more complete picture of your iron status.
Why should you test your iron level?
An iron test may be relevant if you have symptoms that could be related to low iron levels, or if you want to follow up on previously abnormal iron values. Iron deficiency is common and can occur, for example, due to low iron intake, heavy menstrual bleeding, pregnancy, breastfeeding, blood loss or reduced absorption from the stomach and intestines.
In case of fatigue and lack of energy
Low iron levels can contribute to fatigue, reduced energy, dizziness, headaches, palpitations and becoming short of breath more easily. The symptoms can be non-specific and therefore need to be assessed together with blood tests and, if needed, further investigation.
When iron deficiency is suspected
P-Iron can indicate whether there is an insufficient amount of iron available in the blood. A low value may suggest iron deficiency, but can also be seen in inflammation, infection or chronic disease. It is therefore often valuable to supplement the test with ferritin and transferrin saturation.
When monitoring iron status
The test can be used to monitor iron values over time, for example after dietary changes, iron supplements or previously abnormal test results. For comparable results, the sample should be taken at approximately the same time of day, preferably in the morning.
Who may an iron test be suitable for?
An iron test may be suitable if you want to check your iron level or if you have symptoms that could be linked to low iron levels. It may be particularly relevant if you:
often feel tired, dizzy, short of breath or lacking in energy without a clear cause.
have heavy menstrual bleeding or have previously had low iron values.
are pregnant, breastfeeding or have recently been pregnant.
eat a vegetarian or vegan diet and have a limited intake of iron-rich foods.
want to follow up iron values after iron supplements or dietary changes.
What is analysed in the iron test?
The test analyses the marker P-Iron, which shows how much iron is present in the blood at the time of sampling. The value is affected by several factors, including time of day, diet, iron supplements, inflammation and certain medical conditions.
P-Iron
P-Iron measures the amount of iron in plasma. Low levels can be seen in iron deficiency, but also in inflammation or infection. Elevated levels may occur in iron overload or after iron treatment. Since P-Iron alone does not show the body’s iron stores, the result should often be interpreted together with ferritin, transferrin and transferrin saturation.
Interpreting test results for P-Iron
The result shows whether your P-Iron is within, below or above the laboratory’s reference range. For adults, the reference range is often approximately 9–34 µmol/L, but the interval may vary slightly between laboratories. It is therefore important to always use the reference range shown in your test result.
Low P-Iron – what can it mean?
Low P-Iron may be due to iron deficiency, but also to inflammation, infection or chronic disease. Low P-Iron together with low ferritin more often indicates actual iron deficiency. If ferritin is normal or elevated, however, low P-Iron may in some cases be due to inflammation or another underlying influence.
High P-Iron – what can it mean?
High P-Iron can be seen in iron overload, after taking iron supplements or after intravenous iron treatment. To assess whether there is a true iron overload, additional tests are often needed, such as ferritin and transferrin saturation.
How is the blood test performed?
The iron test is taken as a venous blood sample by trained healthcare staff. The sample is usually taken from a vein in the arm and then sent to an accredited laboratory for analysis. The sampling usually only takes a few minutes.
Do you need to address low iron levels?
If the test shows low P-Iron, it may be relevant to review your diet, iron intake and possible causes of low iron levels. Iron-rich foods include meat, blood pudding, offal, legumes, whole grains and dark green vegetables. Vitamin C can increase the absorption of iron from food, while coffee, tea and calcium-rich foods can reduce absorption if consumed at the same time.
You should not start treatment with iron supplements based only on a single test result without understanding the cause of the abnormal value. In case of clear symptoms, significantly abnormal values or recurring low iron levels, further medical assessment may be needed.
When should you seek further investigation?
Contact healthcare services if you have low iron values together with symptoms such as pronounced fatigue, paleness, palpitations, shortness of breath, dizziness or suspected anaemia. In case of heavy menstrual bleeding, gastrointestinal symptoms, blood in the stool, unexplained weight loss or recurring iron deficiency, the underlying cause should be investigated further.
