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Vitamin B11 (B9)

Insight into your folic acid level.

Folic acid (vitamin B11 in the Netherlands, B9 internationally) is essential for cell growth, DNA production, and blood formation. A test gives insight into your folate status, with personal explanation from our doctors.

Also known as: vitamin B11, folate, vitamin B9

Results typically within 2 working days
No referral required
800+ collection points

Personal assessment by our BIG-registered doctors

How it works?

How Bloodworks works

  1. Order online

    Choose your package and preferred location

  2. Receive your lab form

    Within 24 hours by email, with appointment planner

  3. Schedule your blood draw

    Or choose a walk-in location

  4. Blood draw

    Takes just a few minutes

  5. Receive your report

    Securely, typically within 2 working days from our physicians

Background

What is folic acid?

Folic acid is a water-soluble B vitamin needed by the body for DNA production and cell division. It is therefore especially important in rapidly growing tissue, for example during pregnancy and in the production of red blood cells. In the Netherlands it is called foliumzuur or vitamin B11; internationally it is usually referred to as vitamin B9 or folate.

The body cannot produce folic acid on its own, it is obtained through food (leafy green vegetables, legumes, liver) or supplements. A deficiency can develop relatively quickly because the body's reserves are limited. Pregnant women, people with malabsorption (such as coeliac disease), and those on certain medications have an increased risk of a low folic acid level.

In brief

B vitamin

B11 (Netherlands) / B9 (international)

DNA production

Important for cell division

Blood formation

For red blood cells

Pregnancy

Important before and during

This marker is also included in

Testing several values in a single draw takes one blood collection and gives a more complete picture. The choice is yours.

Common reasons to test

When can insight into your Folic Acid be valuable?

Below are some situations in which measuring Folic Acid can provide insight.

Insight into your folic acid status

A test gives a baseline for your folic acid level.

When planning a pregnancy

Before and during the first 10 weeks of pregnancy, adequate folic acid is important. A test can give insight into the baseline.

With questions about fatigue

Fatigue is a commonly reported complaint; folic acid status is one of the possible factors that can be investigated.

With macrocytic anaemia

With known macrocytic anaemia (elevated MCV), folic acid is measured alongside B12 as part of the cause analysis.

With elevated homocysteine

Elevated homocysteine sometimes indicates a deficiency of folic acid, B12, or B6. The three together regulate the breakdown.

With gastrointestinal conditions

In coeliac disease, Crohn's disease, or following gastric surgery, folic acid absorption may be reduced.

What your result means

Folic acid too low or too high: what does your value mean?

Folic acid is measured in nanomoles per litre (nmol/L) in serum. Some laboratories also measure intracellular folate (RBC folate), we measure standard serum folic acid. Reference values differ between laboratories and methods; the values of the laboratory that performs your test are leading.

Low / below reference

A low value

A low folic acid level indicates a deficiency. Possible causes include insufficient intake, malabsorption, or certain medications. Supplementation through diet or supplements is a common approach.

Within reference

A normal value

Folic acid within the reference range gives a reassuring picture of this vitamin status. For pregnant women, a higher lower threshold is sometimes applied, supplementation before and early in pregnancy remains recommended in line with standard guidelines, even with normal values.

Above reference

A high value

An elevated serum folic acid level is often seen with active supplementation and is usually not harmful. With high values, we advise also checking B12 status, as high folic acid can mask a potential B12 deficiency.

How we interpret your result

Our doctors interpret your folic acid in the context of your situation, age, sex, any pregnancy or wish to conceive, diet, medication use, and related markers such as B12 and homocysteine.

Related tests

Often combined with Folic Acid.

A single marker gives one perspective. For a broader picture you can combine Folic Acid with a theme package or related markers.

+ €29 blood draw fee per orderFree from €225

Frequently asked questions

Everything you want to know

Do I need to fast for a folic acid test?

We advise fasting for 8 hours before a folic acid measurement, as recent food intake can temporarily raise the value.

What is the difference between folic acid and folate?

Folate is the natural form found in food. Folic acid is the synthetic form in supplements and fortified foods. Both are converted in the body to the active form 5-MTHF (methylfolate). In some people, this conversion is slower (MTHFR variant).

Which foods contain a lot of folic acid?

Good natural sources include leafy green vegetables (spinach, broccoli, kale), legumes (lentils, chickpeas), liver, oranges, avocado, and wholegrain products.

Are there disadvantages to a high folic acid level?

In healthy people, excess folic acid is excreted in the urine. However, a high dose of folic acid can mask an underlying B12 deficiency, which is why we recommend also checking B12 status when actively supplementing.

Is it worthwhile measuring folic acid if I am already supplementing?

Yes, a measurement can confirm that your level is sufficient. This is particularly valuable information for women who are planning a pregnancy or are in early pregnancy.

How does folic acid relate to homocysteine?

Folic acid is one of three B vitamins (together with B6 and B12) that help break down homocysteine. A deficiency of folic acid can lead to elevated homocysteine.

Does my medication affect my folic acid level?

Yes, certain medications (including methotrexate, sulphasalazine, and certain anti-epileptics) can affect folic acid status. Please let us know of any medication you are taking.

What do I do with my result?

You will receive a PDF report with your value and explanation. What you do with it, such as discussing it with your GP or midwife, remains entirely your choice.

Is vitamin B11 the same as vitamin B9?

Yes. In the Netherlands this B vitamin is usually called vitamin B11 or foliumzuur, while internationally people speak of vitamin B9 or folate. It concerns the same vitamin and the same blood test. On supplements and results from abroad you will therefore often see B9 where we write B11.

What does my folic acid level mean?

The reference values come from the laboratory that analyses your blood, and those are leading. A low value can point to a deficiency, for example through insufficient intake, reduced absorption or medication use. A high value is mainly seen with active supplementation and is usually not harmful, although it can mask a B12 deficiency. Our doctor places your value in the context of your situation and related markers such as B12 and homocysteine.

Which symptoms can fit with a folic acid deficiency?

Frequently mentioned complaints are fatigue, pallor, breathlessness on exertion, irritability and cracks at the corners of the mouth. A deficiency can also go together with anaemia in which the red blood cells are enlarged. These complaints are not specific and can have many other causes. If they persist, please see your GP.

In the Health Guide

Read more about this value

Ready for insight into your folic acid status?

You receive your folic acid level including personal explanation from a doctor, typically within 2 working days. No referral required.

Order Folic Acid

Want to test multiple markers at once?

Combine Folic Acid with other markers via Bloodworks Select. The blood draw and collection fee is charged once per order, and is waived from €225.

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30,-

+ €29 blood draw fee

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