Folic Acid

Results

A folic acid test measures the amount of folic acid in the blood. Normal values vary from lab to lab.

Folate in liquid portion (plasma) of blood

Adult	3–13 nanograms per milliliter (ng/mL)	7–30 nanomoles per liter (nmol/L) (SI units)
Children	5–21 ng/mL	11–47 nmol/L

 

Folate in red blood cells

Adult	140–628 ng/mL	317–1422 nmol/L (SI units)
Children	More than 160 ng/mL	More than 362 nmol/L

High values

• High levels of folic acid in the blood may mean that you eat a diet rich in folic acid, take vitamins, or take folic acid pills. Consuming more folic acid than the body needs does not cause problems.
• High folic acid levels can also mean a vitamin B12 deficiency. Body cells need vitamin B12 to use folic acid. So if vitamin B12 levels are very low, folic acid cannot be used by the cells, and high levels of it may build up in the blood. But a folic acid test is not a reliable way to test for a vitamin B12 deficiency.

Low values

• Low folic acid levels can mean you have a problem with your diet, alcohol dependence, or an eating disorder such as anorexia nervosa.
• Low folic acid levels can also mean you have a problem absorbing or using folic acid, such as a vitamin C deficiency, liver disease, celiac disease, sprue, or Crohn's disease.
• Low folic acid levels can cause problems for certain people. For example:
  • A pregnant woman needs extra folic acid for her growing baby.
  • People who have hemolytic anemia, a condition that causes the fast destruction of red blood cells, need more folic acid to make more red blood cells.
  • People with certain conditions, such as kidney failure and some types of cancer, may use up folic acid quickly. They may need their blood to be cleaned using a machine (kidney dialysis).

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Author:	Caroline Rea, RN, BS, MS	Last Updated: December 23, 2008
Medical Review:	Anne C. Poinier, MD - Internal Medicine Brian Leber, MDCM, FRCPC - Hematology
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