Folate (folic acid): what it is, what it tells you and when it’s tested

Folate is a B vitamin, B9. You find it in leafy greens, legumes and citrus fruit. Folic acid is the form used in supplements. Your body needs it to make red blood cells and build new cells. The test measures how much folate is in your blood.

When it’s tested

Doctors usually order folate together with vitamin B12. They do so when a blood count shows anaemia with large red cells, if you eat few vegetables, drink a lot of alcohol, have a condition that reduces absorption, such as coeliac disease, or take medicines that lower it.

It is not a routine test for people who feel well. Blood folate changes within days with what you eat, so a single result says little about your store. And a shortage that matters usually already shows on a blood count.

That is why Rosa does not test it. Instead it looks at vitamin B12, MCV and haemoglobin, which show whether a B12 or folate shortage is already changing your red blood cells.

What it tells you, and what it does not

If folate is low, you have taken in little over the last days or weeks, or your body is using or losing more.

On its own it does not say whether you have anaemia, or whether B12 is short too. A blood count and B12 answer that.

If it is normal, your folate is usually enough. If it is high, you almost always take a supplement.

That is why it is read together with other tests:

Normal folate levels

The lab decides what is normal, and it depends on the method. Many lab reports give 3.9 to 26.8 ng/mL. Some labs write µg/L, which is the same number, others nmol/L, with larger numbers.

Below 3 ng/mL there is usually a real shortage. Between 3 and your report’s limit there is a grey zone, to be read with a blood count and B12.

There is also a red cell folate test. It reflects the previous months, not just recent days, but it is rarely used.

What your result means

Find the row for your result, in ng/mL. Which values need a doctor? Those below your report’s limit, especially below 3.

If your folate is low or high

Folic acid before pregnancy

This is where folic acid matters most. If you are planning a pregnancy, or do not rule one out, the Italian recommendation is 0.4 mg of folic acid a day, from at least one month before conception until the third month of pregnancy.

It lowers the risk of some birth defects, such as spina bifida. You do not need a blood test to start: it applies to every woman in that situation.

In some cases the doctor advises a different dose. Talk to your doctor or gynaecologist.

What can skew the result

Blood folate follows what you have eaten recently. It helps to know this before your blood test.

When to worry

Talk to your doctor if:

Frequently asked questions

What is the difference between folate and folic acid? They are the same vitamin, B9. Folate is the name for the forms in food. Folic acid is the form used in supplements. On an Italian lab report the test may be called folati, folato sierico or acido folico.

What are normal folate levels? Many lab reports give 3.9 to 26.8 ng/mL, but it depends on the lab’s method. The range printed next to your result is what counts.

Do I need to fast for a folate test? Usually yes, because a recent meal or supplement raises it. You can drink water.

Should I have a folate test before pregnancy? Usually not. Folic acid is advised for every woman planning a pregnancy, without a test. A doctor orders it only in particular cases, for example if there is anaemia.

Does Rosa test folate? No. Rosa measures vitamin B12, MCV and haemoglobin, which show whether a B12 or folate shortage is changing your red blood cells. If your doctor wants folate, they order it separately.

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