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In a French study, 198 women aged 18 to 53 with unexplained fatigue, without anaemia and with a ferritin below 50 µg/l, were given iron or a placebo for twelve weeks. Their fatigue went down by 48 per cent in the iron group and by 29 per cent in the placebo group.[1]
On this page you can read what ferritin is, what the guidelines say about a value that is too low or too high, what affects your iron store and which values are best read alongside it.
Also known as: serum ferritin, ferritine (Dutch). At the lab: FERR.
Your body holds 3 to 4 grams of iron. About a quarter of that lies stored in the liver, the spleen and the bone marrow, as a reserve for later.[3]
Ferritin is the protein that holds on to iron. A small part of it ends up in your blood, and that is the part the lab measures. Without inflammation, the amount of ferritin in your blood is linked to the total iron store in your body: little ferritin when there is a deficiency, a lot when there is a surplus.[2]
Iron is needed for hemoglobin, the part of your red blood cells that carries oxygen through your body. Your cells use iron to make energy, and it contributes to the normal working of your immune system.[3]
You often notice a deficiency as tiring quickly, pale skin, getting out of breath quickly and restless legs. Those complaints can be there before there is anaemia, the most severe form of iron deficiency.[3]
Women who menstruate, women who are pregnant and women who are breastfeeding are more likely to have a deficiency. For vegetarians too it is good to keep an eye on iron.[3]
Too much iron can harm the liver. With the inherited condition haemochromatosis, in about 0.5 per cent of the population, the body builds up iron.[3]
The lab BioProfile works with uses a reference range of 30 to 400 µg/l. A value between those two limits is one the lab calls normal. The lab asks you to have blood drawn while fasting for this value.[4]
| Ferritin (µg/l) | What it can mean | Who it is for |
|---|---|---|
| below 15[2] | iron deficiency | adults who are otherwise healthy |
| below 70[2] | iron deficiency | adults with an infection or inflammation |
| above 150[2] | possible risk of iron build-up | women who menstruate and are otherwise healthy |
| above 200[2] | possible risk of iron build-up | men, and women who no longer menstruate, who are otherwise healthy |
| above 500[2] | possible risk of iron build-up | adults who are ill |
Source: WHO, guideline on ferritin (2020), table 1 and recommendation 1.3. The limits apply to adults from age 20, including after you turn 60.[2]
A low ferritin means a depleted iron store, but it does not say how severe the deficiency is. Below 15 µg/l, the WHO speaks of iron deficiency in an otherwise healthy adult. Between 15 and 30 µg/l your value is below the lab's reference range and above the WHO threshold for a deficiency. In the French study above, women with unexplained fatigue and a ferritin below 50 µg/l benefited from iron. The researchers write that doctors can consider iron in that group.[2, 1]
A high ferritin does not always mean too much iron. Ferritin also rises with inflammation, an infection, liver disease and obesity. That is why, according to the WHO, ferritin on its own does not prove iron overload: a high value calls for further investigation into the cause. In haemochromatosis, doctors look at a high transferrin saturation together with a high ferritin.[2, 5]
Labs measure ferritin with different methods, and the results differ from one method to another. That is why it is best to compare a value with an earlier value from the same lab.[6]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
Iron is in your food as haem iron and as non-haem iron. Haem iron is found only in meat, fish and chicken; your body absorbs about 25 per cent of it. Non-haem iron is in bread, wholegrain products, pulses, nuts, green vegetables and egg; of that your body absorbs 1 to 10 per cent.[3]
Vitamin C in the same meal improves the absorption of non-haem iron. Phytate in grains and pulses and polyphenols in tea and coffee slow that absorption down. Across the diet as a whole, the Voedingscentrum says you do not need to avoid foods because of that slowing effect.[3]
With a vegetarian diet the body absorbs on average 10 per cent of the iron, against over 15 per cent with an average diet. Vegetarians sometimes have smaller iron stores, which according to the Voedingscentrum are still sufficient.[3]
If you lose blood, you lose iron. That is why women who menstruate are more likely to have a small iron store. Your body itself takes more iron from your food as soon as the store goes down.[3]
In the French study, ferritin rose after twelve weeks on 80 mg of iron a day by 11.4 µg/l more than on a placebo. According to the Voedingscentrum, varied eating gives most people enough iron, and it advises against supplements with iron; anyone who does take one stays below the recommended daily amount. The Voedingscentrum says iron tablets belong only after talking with a doctor, and not with haemochromatosis.[1, 3]
Inflammation, an infection, liver disease and obesity raise ferritin, regardless of your iron store. Inflammation can hide a deficiency that way. That is why the WHO puts the threshold for a deficiency higher when there is inflammation, at 70 µg/l.[2]
Ferritin is in all five packages, from BioProfile 31 to BioProfile 150. In every package, iron, transferrin, transferrin saturation and CRP sit beside it, so you read your ferritin in context.[7]
The BioProfile editorial team wrote this page on 28 September 2026 from the sources below, which we read on 28 September 2026 and 29 September 2026. Every number on this page comes from one of those sources, with the number of that source next to it. An expert still has to check this page. After that check, the name of that expert and the date of the check will appear at the top. This page gives explanation, not a diagnosis. Discuss a value outside the range with your GP.
