Blood test
Folate Test
A folate test measures the level of folate (a B vitamin) in your blood. It is used, often with vitamin B12, to investigate anaemia and tiredness.
Quick answer
Folate Test: what it is and what the results mean
Folate (vitamin B9) is needed to make healthy red blood cells and for many body processes. A folate blood test measures the level and is frequently checked together with vitamin B12.
- Why it is done: It is used to investigate a particular type of anaemia and symptoms such as tiredness, and to check folate status, which is especially important before and during pregnancy.
- Understanding results: A low folate can cause anaemia and tiredness and is usually treatable with diet and supplements, once B12 has also been checked.
What it is
Folate (vitamin B9) is needed to make healthy red blood cells and for many body processes. A folate blood test measures the level and is frequently checked together with vitamin B12.
Why it is done
It is used to investigate a particular type of anaemia and symptoms such as tiredness, and to check folate status, which is especially important before and during pregnancy.
What to expect
It is a standard blood test from the arm; fasting is not usually required. It is often measured alongside vitamin B12 and a full blood count.
Understanding the results
A low folate can cause anaemia and tiredness and is usually treatable with diet and supplements, once B12 has also been checked. Results are interpreted alongside the full blood count and your symptoms.
Good to know
Risks and limitations
The blood test is very safe. Because low folate and low B12 can look similar and are linked, B12 is checked too, as treating folate alone when B12 is also low can cause problems.
Education and reference only. This explains the test in general terms and is not medical advice. Always follow the specific instructions from the team arranging your test, and discuss your results with your clinician.
Answers
Folate Test: frequently asked questions
What does low folate cause?
Low folate can cause a type of anaemia with tiredness and breathlessness. It is usually treated with dietary changes and supplements, after checking vitamin B12 as well.
Why is folate important in pregnancy?
Adequate folate lowers the risk of certain birth defects, which is why folic acid supplements are advised before and in early pregnancy. Your clinician or midwife can advise on this.
Related tests
Other blood test investigations
Sources
Where this is drawn from
- NHS — Tests and treatments
- NICE — diagnostic guidance
- Association for Laboratory Medicine / relevant professional body
Building patient-education content for tests or procedures?
We create clear, accurate, referenced medical explainers and decision aids for teams.