A folic acid test measures the amount of
folic acid in the blood. Folic acid is one of many B
vitamins. The body needs folic acid to make
red blood cells (RBC),
white blood cells (WBC),
platelets, and for normal growth. Folic acid also
is important for the normal development of a baby (fetus).
Folic acid can be measured in the liquid portion of blood (plasma). This reflects a person's recent intake of
folic acid in the diet. Folic acid is found in foods such as liver; citrus
fruits; dark green, leafy vegetables (spinach); whole grains; cereals with
added B vitamins; beans; milk; kidney; and yeast.
Folic acid can
also be measured as the amount in the red blood cells. This test may be a
better way than the plasma test to measure the amount of folic acid stored in
the body. The amount of folic acid in red blood cells measures the level when
the cell was made, as much as 2 months earlier. This level is not usually
affected by the amount of folic acid in your diet each day. It is a more
accurate way to measure the body's level of folic acid.
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
Folic acid deficiency can
result in a type of anemia called
megaloblastic anemia. Mild folic acid deficiency
usually does not cause any symptoms. Severe folic acid deficiency may cause a
sore tongue, diarrhea, headaches, weakness, forgetfulness, and fatigue.
Why It Is Done
A folic acid test may be done to:
- Check for
anemia. 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.
- Check for malnutrition or problems absorbing
(malabsorption) folic acid.
- See if treatment for folic acid
deficiency or vitamin B12 deficiency is working.
- See if a woman has
enough folic acid to prevent certain birth defects and allow her baby to grow
How To Prepare
For the folic acid plasma test, do not
eat or drink (other than water) for 8 to 10 hours before the test. If you take
any medicines regularly, your doctor will talk to you about how to take these
before the test.
You do not need to do anything before having a
folic acid red blood cell test.