Folic Acid Test (Folate Test)

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A blood sample is withdrawn from a vein of the arm using a needle.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:

• Haematoma (blood accumulation underneath the skin)
• Excess bleeding
• Infection
• Feeling light-headed or fainting

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:

• A diet rich in folic acid
• Folic acid or vitamin supplementation
• A vitamin B12 deficiency

Folic acid levels lower than normal indicate the following:

• Eating disorders such as anorexia nervosa
• Improper diet
• Kidney failure
• Problems in absorbing folic acid due to sprue, vitamin C deficiency, Crohn’s disease or celiac disease
• Alcohol dependence
• Malnutrition
• Haemolytic anaemia (rapid destruction of RBCs occurs)

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.