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Iron (Serum)

Iron in the blood: hereditary iron overload, when symptoms can appear and the limits for men

Iron is the mineral the body uses to build haemoglobin, the oxygen-carrying protein in red blood cells. Iron comes in through the gut, and according to Thuisarts the body can store a small surplus of iron, mainly in the liver.

In hereditary iron overload, according to Thuisarts, the body keeps taking too much iron from food and drink, and that iron can damage the liver, the pancreas, the heart and the joints. Whether the iron in the blood is raised only a blood test shows.

Laboratories report serum iron in micromoles per litre (µmol/l). Star-SHL uses 8 to 35 µmol/l for men aged 51 to 65 and 7 to 31 µmol/l for men aged 66 to 80.

Doctor's Assessment Included

Serum iron is the amount of iron in the blood at the moment of the draw; in healthy people it averages about 20 µmol/l according to the NVKC. Star-SHL and Unilabs use separate limits for men and women, Star-SHL also per age, and Certe one limit for everyone.

The NVKC advises drawing blood preferably in the morning before breakfast, because iron-rich food raises iron temporarily.
According to the NVKC, iron is preferably judged with the transferrin saturation, which usually lies between 20% and 45%; with an iron (much) higher than 20 µmol/l and a saturation above 50%, there can be iron overload.
Certe uses one iron limit of 10 to 30 µmol/l for all ages and both sexes, and calls it target values.

Reference Ranges

See the value that applies to you:

Age years

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This range also depends on context such as cycle phase or sample material; the highlighted rows apply to your group.

Your reference range

umol/l

7 39 umol/l

Reference ranges by group, in umol/l
Sex	Age	Reference range (umol/l)	Relative scale
Male	· 6–12 years	7–30 umol/l	7 30
Male	· 13–18 years	9–35 umol/l	9 35
Male	· 19–50 years	8–39 umol/l	8 39
Male	· 51–65 years	8–35 umol/l	8 35
Male	· 66–80 years	7–31 umol/l	7 31
Male	· 81 years and older	8–29 umol/l	8 29

7 39 umol/l

Source: NVKC Reference population: Dutch general-practice population (NUMBER, n = 7,574,327)

Reference ranges may vary between laboratories. When you order a test, a BIG-registered doctor assesses your personal results in context. For treatment decisions, discuss your results with your GP.

Check your own value

Iron (Serum): what Dutch laboratories use

Reference ranges by group, in umol/l
Laboratory	Group	Reference value (umol/l)	Relative scale
Star-shl	· Male · 19–50 years	8–39 µmol/l	8 39
Star-shl	· Male · 51–65 years	8–35 µmol/l	8 35
Star-shl	· Male · 66–80 years	7–31 µmol/l	7 31
Star-shl	· Male · 81 years and older	8–29 µmol/l	8 29
Unilabs	· Male	14–35 µmol/l	14 35
Certe	· Everyone · target values	10–30 umol/L	10 30
Diagnostiek voor U	· Male	14–35 µmol/L	14 35

0 42.9 umol/l

Source: Star-shl

Source: Unilabs

Source: Certe

Source: Diagnostiek voor U

Each value as the laboratory itself publishes it, retrieved in 2026.

Iron (Serum): what this test measures

An iron measurement in the blood gives the amount of iron in serum or plasma in micromoles per litre (µmol/l). To assess iron overload, according to the NVKC, iron is preferably measured together with transferrin, so the transferrin saturation can be calculated, and ferritin is also important to map how severe the overload is.

Star-SHL measures iron in serum, photometrically, that is, with the help of light.

Iron (Serum): why this value matters

A high serum iron matters because, together with a transferrin saturation above 50%, it can point to iron overload according to the NVKC, and according to Thuisarts people with hereditary iron overload often notice little or nothing. According to the NVKC, ferritin in iron overload is often above 500 micrograms per litre.

In hereditary iron overload, according to Thuisarts, too much iron can make liver cells die and leave scars (cirrhosis of the liver), can cause diabetes through iron in the pancreas and can weaken the heart.

Iron (Serum): how the blood test works

Referral: No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
The draw: A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
Which test: Iron Studies · €89,- · Anemia · €132,-
Where: 650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Iron (Serum): how to prepare

Better not right after an infection
Recommended

After an infection or vaccination this value can be off for 2 weeks. Preferably draw once you are fully recovered.
Preferably fasting
Recommended

Coming fasting gives a slightly cleaner value, but it is not required. If it suits you, eat nothing from 22:00 the evening before and drink only water.
Preferably in the morning
Recommended

A morning draw makes this value easiest to compare with its reference range. Plan the draw before 10:00 if you can.

Water is always fine. Drink as usual beforehand, it makes the draw easier.
Take your usual medication, unless your own doctor told you otherwise.

Iron (Serum): when is testing worthwhile?

According to the NVKC, serum iron is measured with symptoms that fit iron overload, such as fatigue, joint complaints and diabetes, to check whether it is the hereditary form.

In anaemia in people over 50, according to Thuisarts, an examination of the stomach or bowel is sometimes needed, to be sure that it is not stomach or bowel cancer.

Iron (Serum): symptoms of a high or low value

Low Levels

In people over 50, too little iron in the body often comes from small amounts of blood loss through the stomach or bowel over a long time, according to Thuisarts, sometimes without the person noticing, for example from stomach problems caused by painkillers, a bowel polyp or bowel cancer.

The symptoms of anaemia that Thuisarts names include palpitations in the chest or throat, sweating, ringing in the ears and feeling faint.

High Levels

People with hereditary iron overload often notice little or nothing according to Thuisarts, because the iron in the body builds up very slowly; according to Thuisarts, symptoms can only come with a lot of iron in the body, usually between the ages of 40 and 50. When symptoms of hereditary iron overload come, Thuisarts names fatigue, pain in the joints of the hands and wrists, abdominal pain, a grey-brown skin, heart complaints and, in men, erectile dysfunction, among others, and writes that these symptoms can also come from something else.

When hereditary iron overload is suspected, according to Thuisarts a DNA test in hospital follows, which gives certainty.

Iron (Serum): causes of a low or high value

What lowers the value

Heavy periods

According to the NVKC, women can lose so much blood during their period that iron deficiency develops, and that can lead to anaemia.
Long-term blood loss through the stomach or bowel

According to Thuisarts, losing small amounts of blood through the stomach or bowel over a long time is often the cause of too little iron in people over 50.
Too little iron in the diet

According to Thuisarts, years of eating very little food that contains iron can lead to too little iron in the body.
Poor uptake in the gut

According to Thuisarts, the body can have too little iron with a disease that makes it harder for iron to get into the body through the gut.
Pregnancy

According to Thuisarts, the body needs more iron during pregnancy than comes in with food.

What raises the value

Hereditary iron overload (haemochromatosis)

With an iron (much) higher than 20 µmol/l and a transferrin saturation above 50%, there can be iron overload according to the NVKC, in which the body constantly takes up too much iron from food.
Recently started iron tablets

According to the NVKC, a rise can also occur in people who have just started taking iron tablets.
Iron-rich meal before the draw

Iron-rich food, such as apple syrup or spinach, gives a temporary rise according to the NVKC; that is why blood is preferably drawn in the morning before breakfast.
Inflammation of the liver (hepatitis)

According to MedlinePlus, a higher-than-normal iron may be a sign of inflammation of the liver.
Frequent blood transfusions

According to MedlinePlus, a higher-than-normal iron may be a sign of frequent blood transfusions.

Iron (Serum): lifestyle and this value

In hereditary iron overload, the treatment according to Thuisarts is usually bloodletting: half a litre of blood is taken each time, often at first and then usually 4 to 8 times a year. For people with hereditary iron overload, Thuisarts also advises no or little red meat, no fruit or fruit juice with vitamin C at meals and no alcohol, because alcohol and too much iron together damage the liver even more.

Iron (Serum): frequently asked questions

Can iron overload cause erection problems?

According to Thuisarts, hereditary iron overload can lead to men not getting an erection or getting one with difficulty, besides symptoms such as fatigue and joint pain. According to Thuisarts, those symptoms can also come from something else.

Should relatives be tested in iron overload?

In hereditary iron overload, according to Thuisarts, relatives can also be tested, including brothers, sisters and children from 18 years. According to Thuisarts, young children still use a lot of iron, so not much iron stays in their body.

Which iron range does Star-SHL use for men?

Star-SHL uses its own iron limit for men per age: 8 to 39 µmol/l from 19 to 50, 8 to 35 µmol/l from 51 to 65, 7 to 31 µmol/l from 66 to 80 and 8 to 29 µmol/l above 80. Unilabs uses 14 to 35 µmol/l for men.

Iron (Serum): sources

den Elzen WPJ, Brouwer N, Thelen MH, Le Cessie S, Haagen I-A, Cobbaert CM. NUMBER: standardized reference intervals in the Netherlands using a 'big data' approach. Clin Chem Lab Med 2018;57(1):42-56. (retrieved 2026) doi.org
Star-shl, Labbepalingen (referentiewaarden per bepaling), star-shl.nl, geraadpleegd 2026-10-01 (retrieved 2026) star-shl.nl
Unilabs, Bepalingenklapper (referentiewaarden per bepaling), bepalingenklapper.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenklapper.nl
Certe, Bepalingenwijzer (referentiewaarden per bepaling), bepalingenwijzer.certe.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenwijzer.certe.nl
Diagnostiek voor U, eLabgids (Referentiewaarden DvU), diagnostiek.getincontrol.eu, geraadpleegd 2026-10-01 (retrieved 2026) diagnostiek.getincontrol.eu
NVKC, Alles over testen: IJzer, allesovertesten.nl, geraadpleegd 2026-10-16 (retrieved 2026) allesovertesten.nl
NHG, Thuisarts.nl: Ik heb bloedarmoede, geraadpleegd 2026-10-12 (retrieved 2026) thuisarts.nl
MedlinePlus Medical Encyclopedia: Serum iron test, U.S. National Library of Medicine, geraadpleegd 2026-10-12 (retrieved 2026) medlineplus.gov