Folate (Folic Acid)
Measures folate levels to assess vitamin B9 status, essential for DNA synthesis and red blood cell production.
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This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
What this test measures
This test measures the concentration of folate (vitamin B9) in blood serum. Folate is the naturally occurring form of the vitamin, found in leafy greens, legumes, and certain fruits, while folic acid is its synthetic counterpart used in supplements and fortified foods. Inside the body, folate is converted into tetrahydrofolic acid (THF), its biologically active form, by the enzyme dihydrofolate reductase. THF then serves as a coenzyme in reactions that transfer single-carbon units, a process fundamental to DNA synthesis, cell division, and red blood cell production.
Healthcare providers order this test to evaluate nutritional status, investigate the cause of certain anemias (particularly megaloblastic anemia, in which red blood cells become abnormally large), and monitor individuals whose medications, medical conditions, or dietary patterns put them at elevated risk for folate depletion. It is worth noting that serum folate levels respond quickly to recent dietary intake and may not always reflect long-term tissue stores, which is why clinical context matters when interpreting results.
Who should consider this test
You might consider this test if you are experiencing any of the following:
- Individuals experiencing symptoms of anemia such as fatigue, weakness, pale skin, or shortness of breath
- Those planning pregnancy or currently pregnant, as folate is essential for preventing neural tube defects in developing babies
- People with digestive disorders such as celiac disease, Crohn's disease, or inflammatory bowel disease that may affect nutrient absorption
- Individuals taking medications that interfere with folate metabolism, including certain anti-seizure drugs, cancer medications, or immunosuppressive drugs
- Those with a history of excessive alcohol consumption, as alcohol interferes with folate absorption and metabolism
- Older adults who may have dietary restrictions or absorption issues that could lead to folate deficiency
What to expect
Preparation
Fasting for 8 hours before the test is recommended, as folate levels can be affected by recent food intake. Individuals should avoid eating anything and drink only water during the fasting period. Healthcare providers may also advise temporarily discontinuing certain medications or supplements that could affect results.
Sample Type
A small blood sample is collected from a vein, typically in the arm. The blood draw is quick and minimally uncomfortable.
Collection
During the visit, a healthcare professional will clean the area, insert a small needle into a vein, and collect the blood sample in a tube. The entire process typically takes just a few minutes. No doctor visit required - testing can be completed at any convenient lab location.
Turnaround
Results are typically available within 1-2 business days after the sample is collected and processed by the laboratory.
Understanding your results
Results indicate whether folate levels are adequate, low, or elevated. Because reference ranges can differ from one laboratory to another, it is important to compare results against the specific range printed on the lab report rather than a generic guideline. Healthcare providers frequently evaluate folate alongside vitamin B12, since deficiencies in either vitamin can produce similar types of anemia, and distinguishing between the two is essential for choosing the right treatment.
| Population | Reference Range | Notes |
|---|---|---|
| Adults | 2.7-17.0 ng/mL (6.12-38.52 nmol/L) | Most commonly cited reference range for serum folate levels |
Reference ranges shown are general guidelines. Your lab report will include the specific reference range used by the laboratory that processed your sample, which is the authoritative range for interpreting your results.
What does a “Low” result mean?
Low folate levels typically indicate folate deficiency, which can result from inadequate dietary intake, malabsorption, or increased physiological demands. Deficiency leads to megaloblastic anemia, neuropsychiatric symptoms, and pregnancy complications, including neural tube defects. Symptoms may include pale skin, gums, eyes, and nails, mouth ulcers and a red sore tongue, irritability, shortness of breath, weight loss, numbness and tingling of fingers and toes, forgetfulness, and heart palpitations. Common causes include digestive system diseases like Crohn's disease or celiac disease, excessive alcohol use, certain medications, and kidney dialysis.
What does a “High” result mean?
Elevated folate levels may indicate excessive intake from supplements or fortified foods. Levels above 20 ng/mL are generally considered elevated, and levels exceeding 24 ng/mL are definitively high. A particularly concerning scenario involves the relationship between folate and vitamin B12, where when B12 levels are low, folate can become "trapped" in a form that the body cannot use effectively, leading to elevated serum folate levels in a condition known as the methyl-folate trap. High folate levels may also be associated with certain medical conditions including liver disease, inflammatory conditions, or cancer. Some individuals may experience digestive issues like nausea, bloating, or neurological symptoms including difficulty concentrating, irritability, or sleep disturbances.
Privacy & confidentiality
All test orders are authorized and results reviewed by an independent, board-certified physician who is not the patient's personal doctor. Your folate test results are completely confidential and protected by strict medical privacy laws. Results are <u>not reported to your doctor</u> unless you specifically request them to be shared. The test results are <u>not part of your medical records</u> at your physician's office and will <u>not appear on insurance statements</u> or explanation of benefits (EOB) forms. Your employer, insurance company, or other third parties cannot access these results without your explicit written consent. You maintain complete control over who sees your health information, giving you the privacy and discretion to address any concerns about your folate levels on your own terms. All results are delivered through a secure patient portal, ensuring your personal health data remains confidential and accessible only to you.
Frequently asked questions
Related tests
Vitamin B12 Test
Often tested together with folate as both vitamins work together for red blood cell production and similar deficiency symptoms
View TestComplete Blood Count (CBC)
Helps identify megaloblastic anemia that may result from folate deficiency
View TestHomocysteine Test
Elevated homocysteine levels can indicate folate or B12 deficiency and cardiovascular risk
View TestRelated conditions
Related articles
Last reviewed: April 2026
CPT Code: 82746
This test may not be available in: NY, NJ, RI
This page is for informational purposes only and does not constitute medical advice. Always consult with a healthcare provider regarding any health concerns. LevelPanel does not diagnose, treat, or prescribe.
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LevelPanel has no business or affiliate relationship with Quest or LabCorp. These links are provided as a public service.
Lab testing services linked from this site are not available to residents of Alaska, Arizona, or Hawaii, unless otherwise noted on the lab's own website.
This publication is not intended to solicit the purchase of laboratory testing from any individual consumer.
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