What about iron deficiency during pregnancy?

The need for iron rises sharply in pregnancy, because your body makes more blood and the child builds its own store. Anyone who starts pregnancy with a low store almost always runs short. The midwife therefore checks haemoglobin as standard around week twelve and week thirty. The bands on this page apply outside pregnancy; in that period your midwife reads the result with other limits.

Can you have iron deficiency without anaemia?

Yes, and that is the rule rather than the exception. The store runs out before the production of red blood cells suffers, so your ferritin can already be low while your haemoglobin still sits within the band. Tiredness and restless legs can already be there in that stage. Anyone who looks only at haemoglobin misses that stage; so always read ferritin together with the blood count.

Iron deficiency

Iron deficiency means the iron store in your body is running out. Tiredness that does not lift is among the complaints described with it, but often you notice nothing for a long time. One value in your blood shows where your store stands: ferritin. Iron deficiency is also called sideropenia.

Medically reviewed by

Aäron Spapens

Lifestyle physician at Optimize

What are the symptoms of iron deficiency?

ComplaintEvidence
Tiredness, even after rest
Also without anaemia.
strong
Restless legs
Mostly in the evening.
fair
Trouble concentrating
fair
Craving ice or soil
Rare. Usually goes once your iron is replenished.
fair
Hair loss and brittle nails
limited

Later, with anaemia

Pale skin
Mostly inside your lower eyelid.
strong
Out of breath quickly
During effort you normally handle easily.
strong

How strong is the evidence?

strong: In the Dutch guideline, or confirmed in several controlled trials.
fair: From one controlled trial, an international guideline or a review of research.
limited: The research does not point one way.

Evidence as of October 2026. New research can shift this.

These complaints are also described with anaemia, an underactive thyroid, a vitamin B12 deficiency, low testosterone, PCOS.

An early iron deficiency can exist without complaints for a long time: the body first quietly draws on the store, and complaints follow late or not at all.

None of these complaints belongs to iron deficiency alone, and a measurement explains no complaint: the reading and the diagnosis belong with your GP. The complaint list follows the Dutch GP guideline on anaemia (NHG) and research on iron deficiency without anaemia.

How does iron deficiency develop?

Iron deficiency develops in steps. Your body keeps iron as a reserve, and draws on that first.

Your reserve runs downFerritin falls, the value that measures your iron store. Tiredness can already be there.Your ferritin
Your blood cells get too little ironProduction suffers: your red blood cells become smaller and paler.Your MCV
AnaemiaThere is too little haemoglobin, the protein that carries oxygen. Looking pale and shortness of breath belong to this stage.Your hemoglobin

When is your ferritin too low?

How much iron your body has in store. The first value to fall.

Normal for women:

30 to 120 µg/L

Your value

Enter your value as it appears on your results. Range for adults.

1530120

No value yet? How to get it measured

How do you replenish an iron deficiency?

Eat iron-rich food daily

Today. Anyone who eats plant-based, does sport or is pregnant plans iron deliberately.

Where iron is

AnimalThe form your body absorbs best.
- Red meat
- Fish
- Poultry
Plant
- Legumes
- Whole grains
- Nuts
- Leafy greens

Helps absorption

Vitamin C alongsideWith the meal, for plant iron.
- Pepper
- Citrus
- Kiwi

Slows absorption

Coffee and teaWith the meal.
DairyBecause of the calcium. The effect is small.

Iron tablets

If the store is empty. Food usually does not catch up with an empty store. Iron tablets can. Which tablet suits you and how often you take it is something you can discuss with your GP.

Close the leak

At the same time. With heavy periods it can help to tackle those, for instance with the pill or a coil. Blood loss without a clear reason is worth having looked at, certainly above fifty.

Your haemoglobin is checked

After 4 weeks. Haemoglobin recovers first, the store only after that.

Another 8 to 12 weeks

Once your haemoglobin is normal again. At half the dose, so the store fills up too.

Measure your ferritin again

After that. Ferritin for the store, haemoglobin for the effect. A ferritin that does not rise while you take tablets means the leak is larger than the refill or the gut is not absorbing it.

The timings follow the Dutch GP guideline on anaemia (NHG) and apply to anaemia from iron deficiency. Without anaemia the schedule can differ.

What causes iron deficiency?

Blood loss

Most common

More iron leaves the body than comes in. In adults this is the most common route.

Heavy or prolonged menstruation
Bleeding in the stomach or bowel, which is not always visible
Donating blood regularly

Reduced absorption

The iron is there in the diet, but the bowel takes up too little of it.

Coeliac disease or another bowel condition
Long-term use of acid-suppressing medication
After gastric surgery

Higher demand

Intake is normal, but the body temporarily asks for more than usual.

Pregnancy and the period after birth
Growth during puberty
Intensive endurance sport

Low intake

Rarely the only cause

Rarely the only cause in adults, but a factor that amplifies the other three.

A diet with little or no meat, without deliberate supplementation

How to get iron deficiency measured

Every value below has its own page: what is normal, and what your value means.

Which blood values show iron deficiency?
Value	What it shows	Points here when
Ferritindefining	How much iron your body has in store. The first value to fall.	low
Transferrin Saturationdefining	How much of your transport iron is actually occupied. Stays usable when inflammation distorts ferritin.	low

And 11 values that complete the picture

Which blood values show iron deficiency?
Value	What it shows	Points here when
Transferrin	The transport protein itself. Your body makes more of it when iron is short.	high
Serum Iron	The iron circulating in your blood right now. Swings widely over the day.	low
MCV	The average size of your red blood cells. Iron shortage makes them smaller.	low
MCH	How much haemoglobin an average red blood cell carries.	low
RDW	How much your red blood cells differ from each other in size. Often rises before MCV falls.	high
Hemoglobin	The protein in your red blood cells that carries oxygen. Falls only once the deficiency becomes anaemia.	low

Also in this test

The Iron & fatigue test (€99, single test) measures the values on this page.
Every draw is fasted: nothing to eat or drink from midnight, only water. Appointments are therefore in the morning, until 12:00.
You can draw at 600+ locations near you, no referral needed. See the locations
Results within 24 hours of analysis, in the app.

What is iron deficiency?

Your body keeps iron as a reserve and uses it to make haemoglobin, the protein with which red blood cells carry oxygen, and to keep the muscles and the energy production of every cell running. If that reserve runs out, you notice nothing at first: the body simply keeps making haemoglobin and meanwhile drains the store. Only when the store is truly empty does production suffer, and the red blood cells become smaller and paler. That is why iron deficiency becomes visible in two steps. Ferritin falls first, because that is the store gauge. Then the blood count changes: MCV falls, RDW rises because old and new cells exist side by side, and eventually haemoglobin falls. Anyone who looks only at that last number therefore sees the deficiency only in the final stage, while tiredness and restless legs can already be there with an empty store. Iron only comes in through food, and the body cannot get rid of it deliberately: what is lost, is lost through blood. That is why iron deficiency in adults is almost always a matter of loss outrunning intake, heavy periods first of all, and only then of a gut absorbing less or a body temporarily asking for more, in pregnancy or with a lot of endurance sport.

What is iron deficiency confused with?

Each with the one value that tells the two apart.

Anaemia

Distinguishing value: Hemoglobin

Iron deficiency is about the store, anaemia is about haemoglobin. You can have an empty iron store with a normal haemoglobin, and anaemia can have causes other than iron.

Vitamin B12 deficiency

Distinguishing value: MCV

Both cause tiredness, but MCV points the other way: iron shortage makes red blood cells smaller, a B12 deficiency makes them larger.

Anaemia of chronic disease

Distinguishing value: Transferrin Saturation

Here ferritin is normal or even raised while transferrin saturation stays low. The iron is present but held back.

Frequently asked questions

Below 30 µg/L your iron store is, in practice, running out. Where exactly the lower limit lies differs per lab: for an adult woman it runs from 6 to 30 µg/L. So the same 12 µg/L reads as normal on one report and as too low on another. Compare your ferritin with the range on your own results, and read it alongside your haemoglobin.

The complaints described with iron deficiency are tiredness that rest does not lift, restless legs, trouble concentrating, and hair loss and brittle nails. In controlled studies of women with low ferritin, fatigue eased after iron, also without anaemia. Women of childbearing age run a higher risk of a deficiency: heavy or prolonged menstruation is the route by which the store most often empties, and in pregnancy the demand rises. Often you notice nothing for a long time, and your ferritin shows it before your body does.

It is described, but the evidence is more mixed than for tiredness. Hair follicles are among the fastest-dividing cells of the body, and those notice an empty store first; that explains the thinking behind it. The loss is then diffuse, thinner over the whole head instead of in one spot. With hair loss ferritin is often measured and replenished if it is low, but a low store is not the only possible explanation.

Sources 13

1.NHG-Standaard Anemie. 2024. richtlijnen.nhg.org
2.Unilabs test directory, ferritin. 2026. bepalingenklapper.nl
3.Star-shl test directory, ferritin. 2026. star-shl.nl
4.Certe test directory, ferritin. 2026. bepalingenwijzer.certe.nl
5.Clinical Diagnostics test guide, ferritin. 2026. clinicaldiagnostics.nl
6.Voedingscentrum (Netherlands Nutrition Centre), iron in food. 2026. voedingscentrum.nl
7.Vaucher et al., iron supplementation for fatigue without anaemia, CMAJ. 2012. pubmed.ncbi.nlm.nih.gov
8.Allen et al., guidelines for the iron treatment of restless legs, Sleep Medicine. 2018. pubmed.ncbi.nlm.nih.gov
9.Murray-Kolb and Beard, iron and cognitive functioning in young women, American Journal of Clinical Nutrition. 2007. pubmed.ncbi.nlm.nih.gov
10.Trost et al., iron deficiency and its potential relationship to hair loss, Journal of the American Academy of Dermatology. 2006. pubmed.ncbi.nlm.nih.gov
11.Borgna-Pignatti and Zanella, pica as a manifestation of iron deficiency, Expert Review of Hematology. 2016. pubmed.ncbi.nlm.nih.gov
12.Houston et al., iron supplementation for fatigue without anaemia: systematic review of randomised trials, BMJ Open. 2018. pubmed.ncbi.nlm.nih.gov
13.Thuisarts.nl (NHG), I have anaemia. 2024. thuisarts.nl

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This page explains what a result means. It is not a diagnosis and not treatment advice. Discuss complaints or an abnormal value with your doctor.

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