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Folic Acid

Generic Name: folic acid (FOE lik AS id)
Brand Names: FA-8, Folacin-800

Medically reviewed on October 16, 2017.

What is folic acid?

Folic acid is a type of B vitamin that is normally found in foods such as dried beans, peas, lentils, oranges, whole-wheat products, liver, asparagus, beets, broccoli, brussels sprouts, and spinach.

Folic acid helps your body produce and maintain new cells, and also helps prevent changes to DNA that may lead to cancer.

As a medication, folic acid is used to treat folic acid deficiency and certain types of anemia (lack of red blood cells) caused by folic acid deficiency.

Folic acid is sometimes used in combination with other medications to treat pernicious anemia. However it will not treat Vitamin B12 deficiency and will not prevent possible damage to the spinal cord. Take all of your medications as directed.

Important information

You should not use this medication if you have ever had an allergic reaction to folic acid.

Before you take folic acid, tell your doctor if you have kidney disease (or if you are on dialysis), an infection, if you are an alcoholic, or if you have any type of anemia that has not been diagnosed by a doctor and confirmed with laboratory testing.

Talk to your doctor about taking folic acid during pregnancy or while breast-feeding. Folic acid is sometimes used in combination with other medications to treat pernicious anemia. However, folic acid will not treat Vitamin B12 deficiency and will not prevent possible damage to the spinal cord. Take all of your medications as directed.

Before taking this medicine

You should not use this medication if you have ever had an allergic reaction to folic acid.

If you have any of these other conditions, you may need a dose adjustment or special tests to safely use folic acid:

  • kidney disease (or if you are on dialysis);
  • hemolytic anemia;

  • pernicious anemia;

  • anemia that has not been diagnosed by a doctor and confirmed with laboratory testing;

  • an infection; or

  • if you are an alcoholic.

FDA pregnancy category A. Folic acid is not expected to be harmful to an unborn baby, and your dose needs may even increase while you are pregnant. Talk to your doctor about taking folic acid during pregnancy. Your dose needs may also be different if you are breast-feeding a baby. Ask your doctor about taking folic acid if you are breast-feeding.

See also: Pregnancy and breastfeeding warnings (in more detail)

How should I take folic acid?

Take folic acid exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Take folic acid with a full glass of water.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Store folic acid at room temperature away from moisture and heat.

See also: Dosage Information (in more detail)

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include numbness or tingling, mouth or tongue pain, weakness, tired feeling confusion, or trouble concentrating.

What should I avoid?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Folic acid side effects

Get emergency medical help if you have any of these signs of an allergic reaction to folic acid: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects are more likely, but may include:

  • nausea, loss of appetite;

  • bloating, gas;

  • bitter or unpleasant taste in your mouth;

  • sleep problems;

  • depression; or

  • feeling excited or irritable.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

See also: Side effects (in more detail)

Folic acid dosing information

Usual Adult Dose for Megaloblastic Anemia:

1 mg orally, intramuscularly, subcutaneously or IV once a day. May continue until clinical symptoms of folate deficiency and the hematological profile have normalized.

Usual Adult Dose for Folic Acid Deficiency:

400 to 800 mcg orally, intramuscularly, subcutaneously or IV once a day.

Women of childbearing age, pregnant, and lactating women: 800 mcg orally, intramuscularly, subcutaneously or IV once a day.

Usual Pediatric Dose for Folic Acid Deficiency:

Infant:
0.1 mg orally, intramuscularly, subcutaneously or IV once a day.

Child:
Initial dose: 1 mg orally, intramuscularly, subcutaneously or IV once a day.

Maintenance dose:
1 to 10 years: 0.1 to 0.4 mg orally, intramuscularly, subcutaneously or IV once a day.
> 10 years: 0.5 orally, intramuscularly, subcutaneously or IV once a day.

What other drugs will affect folic acid?

The dosages of other medications you take may need to be changed while you are taking folic acid.

Tell your doctor about all other medications you use, especially:

  • phenytoin (Dilantin);

  • methotrexate (Rheumatrex, Trexall);

  • nitrofurantoin (Macrodantin, Macrobid);

  • pyrimethamine (Daraprim);

  • tetracycline (Ala-Tet, Brodspec, Sumycin);

  • a barbiturate such as butabarbital (Butisol), secobarbital (Seconal), pentobarbital (Nembutal), or phenobarbital (Solfoton); or

  • seizure medication such as phenytoin (Dilantin) or primidone (Mysoline).

This list is not complete and there may be other drugs that can interact with folic acid. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use folic acid only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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