Folate (Serum)

Folic acid helps form red blood cells and produce DNA that stores genetic codes. Taking the right amount of folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida.

Because folate levels in the blood can change quickly with diet and absorption, your provider may sometimes also order a folate test on red blood cells, which gives a steadier picture of your longer-term folate status. Folate deficiency is most common during pregnancy, in people who drink heavily, in those whose diets lack raw fruits and vegetables, and in people with damage to the small intestine that affects absorption.

Women who are pregnant or planning to become pregnant should take at least 600 micrograms (mcg) of folic acid every day. It may be provided by prenatal vitamins and certain foods, such as enriched bread, flour, and cereal. Some women may need to take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider how much you should take.

Reference ranges for serum folate vary slightly between labs, but in general a serum folate level below about 4 ng/mL (about 9 nmol/L) is considered low and suggests folate deficiency, especially when combined with symptoms or anemia. Levels well above this are usually considered normal.

Normal value ranges may vary among different labs. Talk to your provider about the meaning of your test results.

Lower-than-normal folic acid levels may indicate poor diet, malabsorption syndrome (for example, celiac disease), or malnutrition. A low result can also point to a vitamin B12 deficiency, since low B12 can interfere with how your cells take up folate. Low folate can also be associated with megaloblastic anemia.