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What is a Folic Acid test?

A folic acid test or folate test measures the levels of folic acid, a type of vitamin B in blood or serum. Folic acid performs various vital functions in the body, such as repairing tissues and synthesising red blood cells (RBCs) and components of DNA. This test is done to check for folic acid deficiency and monitor the treatment provided for the deficiency.  

  1. Why is a Folic Acid test performed?
  2. How do you prepare for a Folic Acid test?
  3. How is a Folic Acid test performed?
  4. Folic Acid test results and normal range

This test is mainly done to detect folic acid deficiency. It is performed in people with megaloblastic anaemia and anaemia due to folate deficiency. As folic acid is essential for foetal growth and prevention of foetal problems, such as spina bifida and neural tube defects, this test is also advised as an antenatal test during pregnancy. Folic acid test helps to:

  • Determine the cause of anaemia
  • Identify the cause for malnutrition
  • Identify problems with the absorption of folic acid

Individuals should not drink or eat (except water) for 6 hours before the test. They should stop taking folic acid supplements, as it can alter test results. The doctor should know about any regular prescription medications that you may be taking before the test. Discontinuing the consumption of the following drugs/substances might also be recommended as it can reduce folic acid levels:

  • Oestrogen
  • Alcohol
  • Penicillin
  • Phenytoin
  • Methotrexate
  • Birth control pills
  • Phenobarbital
  • Malaria medications
  • Ampicillin
  • Tetracyclines
  • Aminosalicylic acid
  • Erythromycin
  • Aminopterin
  • Chloramphenicol

A blood sample is withdrawn from a vein of the arm using a needle. The sample is collected into an airtight tube or vial attached to the needle. In younger children and infants, a lancet (a sharp tool) is used to puncture the skin for collecting blood into a small container. If bleeding continues, a bandage or cotton ball is placed over the area.

There are rarely any risks while withdrawing blood sample for a folic acid test. Some individuals might experience slight bruising at the site of blood withdrawal, which can be reduced by applying pressure on the area for a few minutes. Swelling might occur in a rare case. It can be controlled using a warm compress. Other uncommon risks associated with this procedure are:

Normal results: Normal levels (in nanograms per millilitre) of folic acid in serum are as follows:

  • Children: 5-21 ng/mL
  • Adults: 3-13 ng/mL

Normal levels (in nanograms per millilitre) of folic acid in RBCs are as follows:

  • Children: More than 160 ng/mL
  • Adults: 140-628 ng/mL

Abnormal results:

Folic acid levels that are higher than normal levels indicate the following:

Folic acid levels lower than normal indicate the following:

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is purely from an educational perspective and is in no way a substitute for medical advice from a qualified doctor. 

Lab Tests recommended for Folic Acid Test (Folate Test)

Folate OR Folic Acid RBC

25% छूट + 5% कैशबैक

Folate OR Folic Acid Serum

25% छूट + 5% कैशबैक


  1. Frances Fischbach & Marshall B. Dunning III. A Manual of Laboratory and Diagnostic Tests. 2015. Lippincott Williams & Wilkins - Wolter Kluwer, Inc
  2. National Heart, Lung, and Blood Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Pernicious Anemia
  3. UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; Health Information: Folic Acid Test
  4. Benioff Children's Hospital [internet]: University of California, San Francisco; Folic Acid Test
  5. MedlinePlus Medical Encyclopedia: US National Library of Medicine; Folic acid - test
  6. Linus Pauling Institute. Micro nutrient Information Center: Oregon State University, Corvallis, Oregon; Folate
  7. Merck Manual Professional Version [Internet]. Kenilworth (NJ): Merck & Co. Inc.; c2019. Folate
  8. Folic Acid for the Prevention of Neural Tube Defects. Pediatrics. 1999;104(2):325–327. Reaffirmed May 2012. Pp. 325 -327
  9. National Institute of Health. Office of Dietary Supplements [internet]: Bethesda (MA), US. US Department of Health and Human Services Folate
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