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Minerals

Serum Iron: Normal Values and What a Low Iron Means

Serum iron testing provides insight into your current iron availability. Combined with ferritin and TIBC, it supports comprehensive iron status assessment and early intervention.

Doctor's Assessment Included

Serum iron is the amount of iron circulating in the blood at the time of the draw; in healthy people it averages about 20 µmol/l. The laboratories use different limits for men and women.

  • Iron is judged together with transferrin saturation (normally 20 to 45 percent) and ferritin.
  • In iron overload the transferrin saturation is above 50 percent; in iron deficiency it is often below 10 percent.
  • Certe calls its limit of 10 to 30 µmol/l target values, not reference values.

Reference Ranges

See the value that applies to you:

Choose male or female — this range differs by sex.

Enter your age — this range changes with age.

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
6 39 umol/l
Reference ranges by group, in umol/l
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
Female · 6–12 years 7–31 umol/l
7 31
Female · 13–18 years 6–35 umol/l
6 35
Female · 19–50 years 7–35 umol/l
7 35
Female · 51–65 years 8–30 umol/l
8 30
Female · 66–80 years 8–30 umol/l
8 30
Female · 81 years and older 7–28 umol/l
7 28
6 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
Star-shl · Male · 19–50 years 8–39 µmol/l
8 39
Star-shl · Female · 19–50 years 7–35 µmol/l
7 35
Star-shl · Male · 51–65 years 8–35 µmol/l
8 35
Star-shl · Female · 51–65 years 8–30 µmol/l
8 30
Star-shl · Male · 66–80 years 7–31 µmol/l
7 31
Star-shl · Female · 66–80 years 8–30 µmol/l
8 30
Star-shl · Male · 81 years and older 8–29 µmol/l
8 29
Star-shl · Female · 81 years and older 7–28 µmol/l
7 28
Unilabs · Male 14–35 µmol/l
14 35
Unilabs · Female 10–25 µmol/l
10 25
Certe · Everyone · target values 10–30 umol/L
10 30
Diagnostiek voor U · Male 14–35 µmol/L
14 35
Diagnostiek voor U · Female 10–25 µmol/L
10 25
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

This test measures the amount of iron bound to transferrin in your blood at the time of testing. It reflects your current iron availability rather than long-term stores.

Iron (Serum): why this value matters

Iron is vital for producing red blood cells and carrying oxygen. Both low and high levels can affect your health. Serum iron is best interpreted alongside ferritin and TIBC for a complete picture. Consult your healthcare provider.

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
on its own €10,- Iron Studies · €89,- · Anemia · €132,- · InsideTracker Endurance · €159,- · InsideTracker · €399,-
Where
650+ draw sites run by independent laboratories across the Netherlands. Draw sites

Iron (Serum): how to prepare

  1. 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.

  2. 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.

  3. 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?

Testing may be recommended if you experience fatigue, weakness, or shortness of breath. It is often part of an iron studies panel when evaluating anaemia or iron metabolism disorders.

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

Low Levels

Low serum iron may be associated with fatigue, pale skin, weakness, dizziness, cold hands and feet, and difficulty concentrating.

High Levels

High serum iron may be associated with joint pain, fatigue, abdominal pain, and skin changes. Chronically elevated iron can damage organs and requires medical evaluation.

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

What lowers the value

  • Blood loss

    Chronic blood loss, for example from heavy periods, leads to iron deficiency and can cause anaemia.

  • Too little iron in the diet

    A poor diet is one of the causes of iron deficiency.

  • Poor uptake in the gut

    Iron is absorbed in the gut, so when the gut works less well a deficiency can develop.

What raises the value

  • Iron overload (haemochromatosis)

    The body then keeps absorbing too much iron from the gut; ferritin is usually strongly raised, often above 500 µg/l.

  • Recently started iron tablets

    Starting iron tablets can raise serum iron.

  • Iron-rich meal before the draw

    Iron-rich food, such as apple syrup or spinach, gives a temporary rise, which is why blood is preferably drawn before breakfast.

Iron (Serum): lifestyle and this value

Eat a balanced diet with iron-rich foods. Pair plant-based iron with vitamin C for better absorption. Avoid excessive iron supplementation without medical guidance, as too much iron can be harmful.

Iron (Serum): frequently asked questions

Why does serum iron fluctuate?

Serum iron levels can vary throughout the day, with meals, and due to recent iron intake. For the most accurate results, testing is typically done in the morning while fasting.

What is the difference between serum iron and ferritin?

Serum iron reflects current circulating iron, while ferritin indicates stored iron. Together, they give a more complete picture of your iron status.

Can diet alone correct low iron?

Mild deficiencies may improve with dietary changes, but significant deficiencies may require supplementation. Always consult your healthcare provider for appropriate guidance.

Iron (Serum): sources

  1. 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
  2. Star-shl, Labbepalingen (referentiewaarden per bepaling), star-shl.nl, geraadpleegd 2026-10-01 (retrieved 2026) star-shl.nl
  3. Unilabs, Bepalingenklapper (referentiewaarden per bepaling), bepalingenklapper.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenklapper.nl
  4. Certe, Bepalingenwijzer (referentiewaarden per bepaling), bepalingenwijzer.certe.nl, geraadpleegd 2026-10-01 (retrieved 2026) bepalingenwijzer.certe.nl
  5. Diagnostiek voor U, eLabgids (Referentiewaarden DvU), diagnostiek.getincontrol.eu, geraadpleegd 2026-10-01 (retrieved 2026) diagnostiek.getincontrol.eu
  6. NVKC, Alles over testen: IJzer, allesovertesten.nl, geraadpleegd 2026-10-03 (retrieved 2026) allesovertesten.nl

Test Products

This marker is included in the following test panels.

InsideTracker

InsideTracker

An InsideTracker blood test with 35 biomarkers: heart, hormones, metabolism, inflammation, recovery and iron status. Measured in the Netherlands.

SHBG (Sex Hormone Binding Globulin) TSH (Thyroid Stimulating Hormone) ALT (Alanine Aminotransferase) LDL Cholesterol GGT (Gamma-Glutamyl Transferase) Cortisol DHEA-S Estradiol (E2) Free Testosterone Total Testosterone Folate (Folic Acid) Vitamin B12 Calcium Ferritin Iron (Serum) Magnesium Potassium Progesterone Sodium Transferrin CRP (C-Reactive Protein) Glucose (Fasting) HbA1c (Glycated Hemoglobin) ApoB (Apolipoprotein B) HDL Cholesterol Total Cholesterol Albumin AST (Aspartate Aminotransferase) Vitamin D (25-OH) Insulin (Fasting) Leukocyte Differential Creatine Kinase (CK) Transferrin Saturation Triglycerides Basic Blood Count HOMA-IR Cholesterol/HDL Ratio Non-HDL Cholesterol LDL/HDL Ratio
€399,-

Medical reviewer

Medical standards

Dr. Naimi oversees the medical standards behind our content and assessments.

Medical policy
CIBG Ministerie van Volksgezondheid,
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Iron (Serum)

€10,-