Test Quick Guide

Folate, also known as folic acid or vitamin B9, plays several important roles in the body, including in making DNA, which is your unique genetic code. An inadequate level of folate in the body, called folate deficiency, can lead to anemia and other changes to your health. Anemia may cause symptoms like weakness, shortness of breath, and mental changes.

A folate test may be ordered after an abnormal blood test result, or if your health care provider suspects low levels of folate are creating health problems. Testing for folate requires a sample of blood.




This test measures the amount of folate to screen for nutrition or absorption issues and certain types of anemia.

About the Test

Purpose of the test

The purpose of measuring folate is to assess whether the body has a healthy level of this essential nutrient. Folate testing is generally performed for the purposes of diagnosing and monitoring health conditions that are caused by folate deficiency.


Folate testing is most commonly performed to check for a folate deficiency, which means low levels of folate. Your health care provider may order a folate test to follow up on an abnormal blood test. Testing may also be ordered if you are experiencing symptoms that could be caused by a folate deficiency.

Detecting low folate levels may lead to a diagnosis of megaloblastic anemia. Anemia is a condition in which the body does not have enough red blood cells. Megaloblastic anemia is caused by low levels of folate or low levels of vitamin B12.


Patients being treated for a folate deficiency may be monitored with folate testing to see if their folate levels have become normal. Some patients with inflammatory bowel disease may have routine testing of folate and other nutrients if they take medications that affect folate levels, especially if they have symptoms of other health problems like anemia.

What does the test measure?

A folate test measures the level of this essential vitamin in your body. Folate plays an important role in many vital processes in the body. The body needs folate to:

  • Grow tissues and cells
  • Create, use, and break down proteins
  • Make DNA, the unique genetic code found in all humans cells
  • Form red blood cells, which transport oxygen throughout the body

During pregnancy, extra folate is needed to enable proper growth of the tissues and cells of the fetus.

Folate is naturally present in many foods, including leafy greens, citrus fruits, beef liver, nuts, and beans. In addition, a synthetic (artificially created) form of folate, folic acid, is added to many foods. Folate deficiencies are uncommon in healthy individuals who eat an adequate diet.

Unlike some vitamins that are stored in fat tissues, folate is water soluble. This means that if you consume more folate than you need, the unneeded amounts of the vitamin leave your body through your urine.

Folate vs folic acid

The terms folate and folic acid may be used interchangeably. However, they mean slightly different things:

  • Folate refers to the naturally occurring vitamin B9 that is found in foods.
  • Folic acid refers to a synthetic or artificially created form of folate that is used in fortified foods and dietary supplements. The folic acid in supplements and enriched foods is more easily absorbed by the body than the folate found naturally in food.

The Food and Drug Administration (FDA) requires food companies to add folic acid to the following foods:

  • Enriched bread
  • Pasta
  • Flour
  • Rice
  • Cornmeal

When should I get folate testing?

Folate testing is most often performed to check for a folate deficiency. Your health care provider may order folate testing for you if you have had an abnormal complete blood count (CBC) or blood smear test result that suggested you have megaloblastic anemia. Megaloblastic anemia is a type of anemia where the red blood cells are abnormally large, deformed, and do not mature properly.

Megaloblastic anemia may be caused by folate or vitamin B12 deficiency. In its early stages, megaloblastic anemia often does not cause any symptoms.

Your doctor may also order folate testing because you are showing symptoms of folate deficiency, which include:

  • Weakness and fatigue
  • Shortness of breath
  • Abnormal heartbeat
  • Open sores on the tongue or inside mouth
  • Color change of hair or skin
  • Diarrhea
  • Confusion
  • Depression
  • Difficulty concentrating
  • Headache

If you are currently being treated with folate supplementation because of a previously diagnosed folate deficiency, your doctor may test your folate to ensure treatment has been effective.

Finding a Folate Test

How to get tested

Typically, folate testing is ordered by a health care provider and a blood sample for analysis is drawn in a medical setting such as a doctor’s office, lab, or clinic.

Can I take the test at home?

Several test kits are commercially available that allow you to provide a blood sample for folate testing at home, usually along with other B vitamins, such as vitamin B12.

These kits may be purchased online and include the materials you need to obtain a blood sample using a finger prick. The sample is returned for testing after you have collected it. Your test results are typically available in a few days and can be accessed through an app or secure online platform.

At-home testing can be convenient, but at-home tests aren’t able to take the place of working with a doctor or other health care practitioner. If you have symptoms suggestive of a folate deficiency, be sure to discuss your concerns with a doctor or nurse.

If an at-home test detects an abnormal folate level, your doctor is likely to ask you to retake the test.

How much does the test cost?

The cost of folate testing will vary depending on where the test is performed and whether or not you have health insurance.

Insurance usually covers the cost of folate testing if your health care provider orders it to diagnose or rule out a medical condition. You can check with your doctor, the lab, or your health insurance company to learn more about the cost of the test and what, if any, testing costs are your responsibility.

Taking a Folate Test

A folate test is performed on a sample of blood that is taken during a visit to a doctor’s office, laboratory, hospital, or other medical setting.

Before the test

It is important to fast for up to eight hours before a folate test, which means you must avoid eating and drinking anything other than water. It is important to follow instructions for fasting carefully, because levels of folate in the blood can change based on what you have eaten recently. Failure to fast as instructed could lead to a false elevation in your test results.

You should also ask your health care provider if you need to temporarily discontinue any of the medications you normally take. Many common drugs, including birth control pills, estrogen, anti-cancer drugs, folic acid supplements, and anti-seizure medications can impact the assessment of your folate status. Alcohol can also decrease your blood level of folate.

During the test

During a folate test, a small sample of blood is usually drawn from a vein in your arm. The person taking your blood sample may fasten a band around your upper arm. This makes it easier to see where your veins are. Next, the area where the needle enters your skin is cleaned with an antiseptic to prevent infection. A needle attached to a sample tube is inserted into your vein, and a small amount of blood is drawn into the tube. Some people feel a slight sting when the needle pierces their skin.

The process of providing a blood sample usually takes less than a few minutes.

After the test

After a blood draw, you may be asked to apply pressure with a cotton ball or gauze to the site where the blood was extracted. Next, a bandage is applied to the site.

Providing a blood sample is very low-risk. In some cases, you may have slight bruising at the site where the needle entered your skin.

Folate Test Results

Receiving test results

Your health care provider may share your folate test results with you, or you may be able to receive results through an online portal, over the telephone, or through the mail. Folate results are typically available within a day or two.

Interpreting test results

There are two ways of measuring folate in a blood sample. The most common method is measuring the folate level in serum, which refers to the liquid portion of blood. The other method measures the folate in the red blood cell component of blood.

When you get your test results, your report will indicate your level of folate, whether the folate was measured in serum or red blood cells, and a reference range. Reference ranges indicate the range of results that are considered to be expected for healthy people.

Test results that fall above or below the reference range may indicate a health issue. Reference ranges for folate can vary by laboratory, so you can ask your health care provider what reference range was applied to your sample, and if your results indicate a deficiency.

A value indicating a deficiency means you have a lower than normal amount of folate in your blood, which can lead to problems such as anemia, low levels of white blood cells and platelets, as well as birth defects if you are pregnant.

Are test results accurate?

Folate test results are usually regarded as accurate. However, like all medical tests, some circumstances can create misleading results. When folate in the serum is measured, levels are strongly influenced by what the person has recently eaten.

Folate can also be tested on red blood cells, which provides information about the patient’s folate levels over the lifetime of the red blood cells. If it is not possible to obtain a fasting blood sample, because the patient has recently eaten or taken a folic acid supplement, red blood cell testing may yield more accurate results of the patient’s folate levels.

Do I need follow-up tests?

If your folate test result is borderline, meaning within the lower end of the reference range, you may need additional testing. The following tests may be ordered to make it clearer whether or not a folate deficiency is present:

Although it is not common, sometimes a red blood cell folate level will be measured to follow-up on a serum folate test.

Additionally, experts advise that if a folate deficiency is detected, a vitamin B12 test should also be performed.

Questions for your doctor about test results

You may wish to ask your doctor some of the following questions about your folate test results:

  • Is my folate level normal?
  • Do my test results enable you to make a diagnosis?
  • Will I need any follow-up tests?
  • Are you able to recommend any treatment, such as supplementation with folic acid, based on my test results?

Folate test vs. vitamin B12 test

Vitamin B12 and folate are both vitamins. Because deficiencies of either vitamin can cause megaloblastic anemia, folate and vitamin B12 testing are often ordered simultaneously when preliminary blood test results are suspicious for megaloblastic anemia.

Folate testing and pregnancy

Maintaining adequate folate levels is very important during pregnancy because extra folate is required for the growth and development of the fetus. However, folate testing has not been shown to be helpful in identifying pregnant people who would benefit from supplemental folate. Instead, experts recommend that all people who are pregnant take folate supplements in order to prevent folate deficiency, which can lead to birth defects.

Although folate is not routinely tested in pregnancy, patients concerned about folate testing during pregnancy can discuss any concerns with a doctor.


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