Vitamins and MineralsFolateFolic Acid



June 25, 2020

Vitamins and Minerals

What is Folate?

Folate is also known as vitamin B9. It plays a critical role in the production of DNA, RNA and red blood cells. Deficiency in folate can impair cell division and affect the development of unborn babies. It is therefore especially important for women of childbearing age to ensure that they have an adequate folate intake, even before pregnancy.

Folate is naturally present in many fresh fruit and vegetables, especially leafy green vegetables, such as spinach, broccoli, and lettuce. Some bread and cereals can be fortified with the synthetic form of folate, called folic acid. Folic acid is converted to folate in our bodies after intake. Folate is heat-sensitive and therefore overcooking can destroy the folate in food.

Excess folate leaves the body with urine and cannot be stored. Regular and frequent intake of folate-containing food is therefore necessary.

For more information about folate and pregnancy specifically, click here.

Why is this analysis important?

Measurement of folate levels in the blood is usually carried out to rule out or confirm folate deficiency. Early signs of folate deficiency can be very vague and nonspecific. It is especially important for women of childbearing age to check their folate levels and ensure that they do not have a deficiency.

Doctors can also order a folate test for the investigation of anaemia symptoms such as fatigue, paleness and shortness of breath.

In short, it is useful to analyse folate levels in the blood to:

  • Confirm or rule out vitamin B12 deficiency

  • Investigate the cause of anaemia (low blood count).


The reference range for folate levels in the blood can be different depending on the laboratory and technique used. Doctors usually also take into account a number of factors when evaluating folate values.

High levels of folate may be caused by:

  • A diet rich in folate or use of folic acid supplement

  • Vitamin B12 deficiency

Low levels of folate may be caused by:

  • A diet poor in folate

  • Malnutrition

  • Alcoholism

  • Malabsorption caused by for instance celiac disease or Crohn's disease

  • Hemolytic anemia (a disorder where red blood cells are destroyed)

  • Use of certain drugs such as Methotrexate, antibiotics (Trimethoprim) or anticonvulsants (Phenytoin, Valproate, Carbamazepine) that inhibit the use or absorption of folate.

Other Considerations

Some people can have a genetic condition where their bodies are unable to efficiently use the folate available. This means that their bodies need more folate than most other people and can have folate deficiency despite folate values within the normal reference range.

When a vitamin B12 deficiency is present, folate levels in the blood can rise. This is because our cells cannot use the folate that is present when there is no vitamin B12. Deficiency in folate and vitamin B12 can lead to very similar symptoms. Therefore, analysis of folate and vitamin B12 levels in the blood are usually carried out simultaneously.

Pregnant women and women who are planning pregnancy are recommended to take 400 microgram folic acid supplements daily until 12 weeks into pregnancy to prevent birth defects. This recommendation is valid regardless of the measured folate level in the blood.

Tests that include this marker


Causes and pathophysiology of vitamin B12 and folate deficiencies. Stanley L Schrier, MD. UpToDate Jul 02, 2018

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