Iron values table: iron, ferritin and transferrin reference ranges

An iron panel consists of several values that each show a different piece of your iron status. Iron in your serum measures what is floating in your blood at that moment, ferritin shows your stores, and transferrin is the protein that carries iron. Only together do they tell you whether you have enough iron.

I notice that many women see a row of numbers after a blood test and do not know which value really matters. So in this article I line them up, with a table and indicative reference ranges for women. Note: labs and guidelines use slightly different limits, so always read your own result next to the reference range from your own lab.

Which iron values are there?

The main iron values are serum iron, ferritin, transferrin and transferrin saturation. Your MCV, the average size of your red blood cells, is often included too. Each value highlights a different aspect, from your current iron in the blood to your stored reserve.

Serum iron fluctuates strongly over the day and after a meal. Ferritin is more stable and is regarded as the best measure of your stores. Transferrin and the saturation show how hard your body is trying to take up and carry iron.

These values are almost always requested together, because a single value says too little.

Iron values table: reference ranges

The table below lines up the main iron values, with an indicative reference range for women and what each value reveals. These are guide values, not hard limits. Your own lab may use slightly different numbers, so always compare your result with the reference range on your own lab report.

If you see a value just below or above these limits, that does not have to mean something is wrong. A single deviating value often calls for a repeat or for the other values alongside it. Discuss a result that worries you with your GP.

What is the difference between iron and ferritin?

Serum iron is the iron travelling through your blood at that moment, while ferritin reflects your stored reserve. Serum iron fluctuates strongly over the day, ferritin is far more stable. That is why ferritin is usually the better value for detecting an iron shortage.

You can have a normal serum iron while your reserve is almost empty. According to Thuisarts.nl and the NHG guideline, a low ferritin is the clearest sign of iron deficiency.

That is also why a result with only serum iron is sometimes misleading. If you want to know what a low ferritin means, read our article on iron deficiency without anaemia.

What do transferrin and transferrin saturation say?

Transferrin is the protein that carries iron through your blood, and the transferrin saturation shows what share of it is actually loaded with iron. With an iron shortage your body makes more transferrin, while the saturation drops. This is how your body tries to catch every bit of iron.

A high transferrin with a low saturation therefore fits a shortage. A low transferrin with a high saturation can point to iron overload, although that is rarer.

These two values complement ferritin and help to interpret a doubtful result more clearly.

When do you test which iron value?

With fatigue, paleness or breathlessness, a complete iron panel with ferritin, transferrin and saturation is the most useful. Testing only serum iron often gives too little information. Your GP usually also looks at your haemoglobin to rule out anaemia.

Women who lose a lot of blood during menstruation have a greater risk of a shortage. An iron panel can also be useful with a plant-based diet or around a pregnancy.

Not sure whether your complaints come from your iron? Then read our pillar on anaemia in women and which blood values to test.

Testing your own iron values

At Lunara you can have your iron status drawn without a referral. The Iron Status test looks at iron, ferritin, transferrin and the saturation in one go. Your blood is drawn in the morning at one of more than 750 draw locations.

Your result is always assessed by a BIG-registered doctor, so you are not left staring at a row of numbers on your own. If you first want to know more about the single value, read our article on the ferritin level and what a low ferritin means.

Testing yourself is a handy starting point, but does not replace your GP's judgement.

Frequently asked questions

Which iron value is the most important?

For detecting an iron shortage, ferritin is usually the most important value, because it shows your reserve. Serum iron fluctuates too much to rely on alone. A complete panel gives the fullest picture.

What is a normal ferritin value for women?

Many labs use roughly 15 to 150 microgram per litre for women, but the limits differ per lab and guideline. A value below the reference range usually points to a shortage. Always compare your result with the reference range on your own lab report.

Can my iron be normal while my ferritin is low?

Yes, that happens regularly. Your serum iron can still be normal while your reserve, measured with ferritin, is almost gone. That is why ferritin is seen as the better measure for an early shortage.

Do I have to be fasting for an iron test?

For ferritin and transferrin you usually do not have to be fasting. Serum iron does fluctuate after a meal, so a fasting morning draw is sometimes advised. The draw location will let you know whether that is needed for your test.

What does a high transferrin mean?

A high transferrin often fits an iron shortage: your body makes more transport protein to catch scarce iron better. Combined with a low saturation this strengthens the picture of a shortage. Discuss a deviating result with your GP.

References

1. NHG. NHG guideline Anaemia. Dutch College of General Practitioners.
2. Thuisarts.nl. I have anaemia due to an iron shortage. Dutch College of General Practitioners.
3. Voedingscentrum. Iron in the diet. Netherlands Nutrition Centre.

Every blood test result through Lunara includes a professional assessment by a BIG-registered doctor. Blood testing through Lunara does not replace your GP's judgement. For treatment decisions, discuss your results with your GP.