Folate (Vitamin B9) Test Fact Sheet

People’s diets impact upon their health and how they age. Although it is easy to recognize when someone may be overeating because of weight gain, knowing if someone is getting too much or too little of a nutrient like folate (or folic acid) is not as easy to figure out. Blood tests can detect if someone is deficient in a vitamin or mineral like folate, also known as vitamin B9.

Folate is very important for a healthy metabolism. Leafy green vegetables are rich sources of folate. Some fruits, legumes and seeds contain folate too. If people do not eat enough of this vitamin in their diet, or if they have difficulty absorbing folate, they may become deficient. Pregnant women and those who drink alcohol often require folate supplements, as do some older adults.

A lack of folate could contribute to a decline in mental agility or short-term memory. Other symptoms can include weakness, dizziness, a sore mouth, or unexplained behavioral changes. It is also thought that folate, along with vitamins B6 and B12 can help reduce homocysteine levels. High levels of homocysteine correlate to an increased risk of heart disease. Some people who take supplements experience lower blood pressure and fewer heart attacks, but the only way to know if one’s folate levels are low is with a folate test.

Overview of the Test

Folate tests measure the levels of folate in the blood. A folate test, also called a folic acid test, lets someone know if they need to increase their folate intake, either by eating more produce and/or taking folate supplements. A diet rich in fruits and veggies lowers people’s risk of colon cancer, and folate may be an important part of the reduced risk. The body needs folate to synthesize DNA and to help produce red blood cells. In pregnancy, folate is important to help prevent defects such as neural tube defects (common birth defects). Low folate levels also exacerbate problems caused by low levels of vitamin B12, such as depression, cognitive decline and fatigue.

Folate tests should be conducted with a vitamin B12 test because taking folate supplements when someone has low levels of B12 could cause problems. Doctors often order a folate test to check not only for a deficiency, but also if they suspect someone may be anemic or has a malabsorption disorder. This could include patients suspected of having celiac disease, gastric cancer, IBD, or cystic fibrosis. A folate test can also be used to rule out neuropathy.

How is it Done?

A folate test is a simple serum test. Blood is drawn and a specialist examines the serum to determine the concentration of folate in the sample. The normal range of folate is between 5 and 16.0 nanograms per milliliter (ng/mL) Individual results could vary. Sometimes, a doctor may want to measure the amount of folate in red blood cells. The most common reasons for low folate levels include poor diet or a malabsorption syndrome such as celiac disease.

Who does it?


When and How Often?

To ensure proper development of the fetus, pregnant women need testing to ensure they have an adequate supply of folate. Tests should be done any time a deficiency is suspected. Older people may want to be tested if they suspect their bodies are not absorbing enough nutrients.


A folate test is inexpensive. A test may cost around $39 to $49, though prices vary.


Blood tests are safe and usually painless, though some people may feel a prick or mild pain when blood is taken. In rare situations, some individuals may get a slight infection or hematoma (bruise) at the site where the needle is inserted.


Last reviewed 26/Feb/2014


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Whilst wielding a couple of dumbbells in a gym class in 2003, Kate experienced an epiphany around the lack of accepted best practice guidelines when it came to staying well and avoiding disease. Kate realized that she had no chance of slowing her own aging process unless she became better educated about her options.

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