A folic acid test is often done at the same time as a test for vitamin B12 levels because a lack of either vitamin may cause anemia. This test is also used to check for malnutrition or problems absorbing (malabsorption) folic acid, to see if treatment for folic acid deficiency or vitamin B12 deficiency is working, or to see if a woman has enough folic acid to prevent certain birth defects and allow her baby to grow normally.


Women who are pregnant or planning to become pregnant need extra folic acid to make more red blood cells and maintain normal growth of their baby. Women who do not get enough folic acid before and during pregnancy are more likely to have a child born with a birth defect, such as a cleft lip or cleft palate, or a neural tube defect, such as spina bifida.
 

It is fairly common to have low levels of folic acid. Alcoholism, inflammatory bowel disease (IBD), and celiac disease can cause folic acid deficiency. Also, certain medications may lower levels of folic acid in the body.