Folic Acid Dosage

by on June 7, 2012

In general, the best way to supply the body with the recommended amount of essential vitamins is through consuming a well balanced diet that consists of a wide variety of vitamin-rich foods. Usually, the American diet is enriched with folic acid because staple foods are normally fortified with this vitamin and it is also plentiful in the food supply.

However, since folic acid is water soluble and is easily excreted by the body, it has to be continuously supplied through diet or supplementation. Folic acid supplements are taken orally and is easily absorbed by the body with satisfactory results, except in rare cases of intestinal malabsorption. In patients with severe folic acid deficiency or impairment of gastrointestinal absorption, parenteral administration of this vitamin may be necessary.

Your folic acid dosage depends on a number of factors that include your age and gender, specific medical condition such as illnesses or pregnancy, and treatment goal. The Recommended Dietary Allowance (RDA) for folate is also used to determine your folic acid dosage, except when the vitamin is used for treatment of certain medical conditions.

Below is the Daily Reference Intakes (DRIs) for folate as recommended by the Food and Nutrition Board of the Institute of Medicine:

Daily Reference Intakes (DRIs) For Folate


  • 0 - 6 months  - 65 mcg/day
  • 7 - 12 months - 80 mcg/day


  • 1 - 3 years - 150 mcg/day
  • 4 - 8 years - 200 mcg/day
  • 9 - 13 years - 300 mcg/day

Adolescents and Adults

  • Males age 14 and olde - 400 mcg/day
  • Females age 14 – 50  - 400 mcg/day plus 400 mcg/day from supplements or fortified foods
  • Pregnant women - 600 mcg/day
  • Breastfeeding women - 500 mcg/day
  • Females age 50 and over - 400 mcg/day

For most people, diet alone is enough to meet the Recommended Dietary Allowance (RDA) for folic acid, since the daily American diet is usually comprised with foods that naturally contain folate. Furthermore, staple foods such as flour, cereal, rice, pasta, cornmeal, and other grain products are fortified with this vitamin. Also, majority of multivitamin preparations contain 400 mcg of folic acid per dose.

Dosage For Specific Medical Conditions

People taking folic acid to manage, treat, or prevent certain medical conditions may be given individualized doses. When used for therapeutic purposes, patients may take up to 1.0 mg per day. People with resistant cases, increased body requirement for folic acid, or severe folic acid deficiency may require a higher dose of this vitamin.

Pregnant women with history of miscarriages or giving birth to an infant with neural tube defect (birth defects involving malformation of the brain and the spinal cord) may be given higher dose of folic acid, usually up to 4 mg daily (4000 mcg/day) prior to conception and throughout the pregnancy, especially during the first trimester. Women of childbearing age who are taking certain medications that can increase the risk of neural tube defects (e.g. antiseizure drugs) may also be given a higher folic acid dosage.

When used for prevention of heart disease, particularly for treatment of hyperhomocysteinemia, patients may be given a daily dose ranging from 0.5 mg (500 mcg) to 5 mg (5000 mcg). People who have other underlying medical conditions such as alcoholism, chronic infection, and hemolytic anemia may also require a higher daily dose.

A slightly higher maintenance dose is given to patients taking this vitamin for therapeutic purposes. Patients taking higher doses of folic acid should be closely monitored for untoward effects or possible relapse.

General Information When Taking Folic Acid

  • Do not take more than 1000 mcg of folic acid per day unless specifically instructed by your healthcare provider. Taking higher doses of this vitamin can “mask” the symptoms of vitamin B12 deficiency.
  • Do not adjust, increase or change your dose without consulting your healthcare provider.
  • Women of childbearing age are recommended to take at a daily dose of multivitamin with 400 mcg of folic acid to prevent certain birth defects.
  • Be sure to read package insert or your prescription label before taking this vitamin, especially for higher doses. If you do not understand the prescription or have questions, talk with your healthcare provider.