A folic acid test measures the amount of folic acid in the blood. Folic acid is vitamin B-9, which is essential for the production of healthy red blood cells.
Doctor orders folic acid test when the patient is detected with diarrhea or constipation, a swollen, red tongue, bleeding gums, a lack of appetite, fatigue, headaches, and numbness
The normal reference range of folic acid in the blood is between 2.7 and 17.0 nanograms per milliliter.