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 folate levels are creating health problems. Testing for folate requires a sample of blood.

About the Test

Purpose of the test

Measuring folate assesses whether the body has a healthy level of this essential nutrient. Folate testing is generally performed to diagnose and monitor health conditions caused by folate deficiency.

Folate testing is most commonly performed to check for a folate deficiency, which means low levels of the nutrient. 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. The condition of anemia is when the body does not have enough red blood cells. Low levels of folate or low levels of vitamin B12 cause megaloblastic anemia.

If you are being treated for a folate deficiency, you may be monitored with folate testing to see if your levels have become normal. Some patients with inflammatory bowel disease may have routine testing of folate and other nutrients because their digestive system doesn’t absorb them well and they may take medications that further affect the absorption of folate, 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 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.

When should I get this test?

Folate testing is most often performed to check for a deficiency. Your health care provider may order folate testing if you have had an abnormal complete blood count (CBC) or blood smear test result suggesting megaloblastic anemia. In this type of anemia, 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 can I get a folate test?

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

You can also order a folate test online, which you can take to a lab to get your blood sample drawn.

Can I take the test at home?

Several commercially available test kits 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. After you have collected the sample, it is returned for testing. Your 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 the tests can’t take the place of working with a doctor or other health care practitioner. Discuss your concerns with a doctor or nurse if you have symptoms suggestive of a folate deficiency.

If an at-home test detects an abnormal folate level, your doctor will likely 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 blood sample taken during a visit to a doctor’s office, laboratory, hospital, or another medical setting.

Before the test

It is important to fast for up to eight hours before a folate test, so you must avoid eating and drinking anything other than water. Follow instructions for fasting carefully because folate levels 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.

Also, ask your health care provider if you need to temporarily discontinue any 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 will enter 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. You may feel a slight sting when the needle pierces your skin.

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. You may sometimes 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. Another 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 it was measured in serum or red blood cells, and a reference range. The latter indicates the range of results 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, and birth defects if you are pregnant.

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?


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