Serum folate (folic acid) is a test that is commonly used to monitor folic acid status. Although it is frequently used, the results can be variable. When trying to uncover the cause of an anemia, an RBC folate assay should be performed instead as it more accurately reflects folate levels at the time the RBC was produced.
Prevention of folic acid deficiency anemia involves eating raw or lightly-cooked vegetables every day. This will help maintain normal folic acid levels, as will taking a folic acid supplement containing at least 400mcg of this vitamin. Because folic acid deficiency can cause birth defects, all women of childbearing age who can become pregnant should consume at least 400mcg of folic acid daily; a woman who is pregnant should have regular medical checkups, and take a good prenatal vitamin.
CAUTION: It is always important to discover the underlying deficiency that is causing a megaloblastic anemia. Higher doses of folic acid (greater than 1mg per day) may improve or mask the anemia caused by a B12 insufficiency. Unless the B12 deficiency is corrected, permanent nervous system damage may result. In other words, don't treat a B12 deficiency with high doses of folic acid!
Under certain conditions, such as anticipated or actual pregnancy, a simple lab test for serum folate levels is advisable. If the test results show low levels, supplementation should be considered to prevent potential birth defects.