The normal range for folic acid in the blood is 2.7 to 17.0 nanograms per milliliter, according to MedlinePlus, but this varies slightly among different testing labs. Low levels of folic acid may be indicative of malnutrition, malabsorbtion syndrome or anemia, according to Healthline.
Excess vitamins, including folic acid, are normally excreted from the body through urine, so high levels of folic acid are not cause for alarm, notes Healthline. Folic acid helps in the formation of red blood cells and DNA, and it aids in the growth of cells and body tissue. Taking adequate amounts of folic acid helps pregnant women prevent certain birth defects, such as spina bifida.