FOLIC ACID: Overview, Uses, Side Effects, Precautions, Interactions and Dosing


Folic acid is the synthetic form of folate, a B vitamin that is essential for human health. Folate is found in many foods, including leafy green vegetables, beans, citrus fruits, and fortified cereals and breads. However, it is difficult to get enough folate from diet alone, especially for pregnant women and women of childbearing age.

Folic acid is important for cell growth and development, and it plays a vital role in the formation of red blood cells. It is also important for the development of the neural tube, which eventually forms the brain and spinal cord of a baby.


Folic acid is used to:

  • Prevent birth defects, such as neural tube defects (NTDs)
  • Treat megaloblastic anemia, a type of anemia caused by a deficiency of vitamin B12 or folate
  • Treat pernicious anemia, a type of anemia caused by the body’s inability to absorb vitamin B12
  • Prevent homocysteine levels from rising too high. High homocysteine levels are a risk factor for heart disease and stroke.

Side effects

Folic acid is generally safe for most people when taken in recommended doses. However, some people may experience side effects such as:

  • Nausea
  • Vomiting
  • Stomach upset
  • Diarrhea
  • Loss of appetite
  • Sleep problems
  • Confusion
  • Irritability
  • Skin rash


Folic acid should be used with caution in people with the following conditions:

  • Allergy to folic acid
  • Pernicious anemia (untreated)
  • Kidney disease
  • Epilepsy
  • Mental health conditions


Folic acid may interact with the following medications:

  • Anticonvulsants (e.g., phenytoin, carbamazepine)
  • Methotrexate
  • Sulfasalazine


The recommended daily intake of folic acid for adults is 400 micrograms (mcg). Pregnant women and women of childbearing age should take 400 to 1,000 mcg of folic acid per day.

Folic acid is available in tablet, capsule, and liquid form. It is also available in prenatal vitamins and other multivitamin supplements.