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 with other medications to treat pernicious anemia. Folic acid used alone will not treat pernicious anemia and other anemias not related to Vitamin B12 deficiency. Take all of your medications as directed.
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. Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.
Before taking this medicine
You should not use this medicine if you have ever had an allergic reaction to folic acid. Ask a doctor or pharmacist if this medicine is safe to use if you have ever had:
- epilepsy or other seizure disorder;
- cirrhosis or other liver disease;
- 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
Tell your doctor if you are pregnant or breastfeeding. Your dose needs may be different during pregnancy or while you are breastfeeding.
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 tablets 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.
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.
- 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 happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What should I avoid while taking folic acid?
Follow your doctor's instructions about any restrictions on food, beverages, or activity.
Folic acid side effects
Get emergency medical help if you have signs of an allergic reaction to folic acid: hives, rash, itching, skin redness; wheezing, difficult breathing; swelling of your face, lips, tongue, or throat. Common folic acid side effects may include:
- nausea, loss of appetite;
- bloating, gas, stomach pain;
- bitter or unpleasant taste in your mouth;
- confusion, trouble concentrating;
- sleep problems;
- depression; or
- feeling excited or irritable.
Ask a doctor or pharmacist before using folic acid with any other medications, especially:
- a barbiturate such as phenobarbital or secobarbital; or
- seizure medicine such as phenytoin or primidone.
Methotrexate is a medicine that is commonly prescribed for people with rheumatoid arthritis, psoriasis, or cancer, and it can lower levels of folate (a B vitamin) in your body. You should take folic acid with methotrexate to help prevent a folate deficiency. A folate deficiency can lead to symptoms like tiredness, muscle weakness, mouth sores, and neurological symptoms.