From the Guidelines
The recommended daily dose of folic acid for most adults is 400 micrograms (0.4 mg) 1.
Key Considerations
- Pregnant women should take 600 micrograms (0.6 mg) daily, while breastfeeding women need 500 micrograms (0.5 mg) daily.
- Women planning pregnancy should start taking 400-800 micrograms at least one month before conception to prevent neural tube defects in the developing fetus.
- For those with folate deficiency, higher therapeutic doses of 1-5 mg daily may be prescribed.
- People with certain medical conditions like malabsorption disorders, alcoholism, or those taking medications that interfere with folate metabolism (such as methotrexate, phenytoin, or trimethoprim) may require higher doses.
Important Details
- Folic acid supplements are best absorbed when taken on an empty stomach, but can be taken with food if stomach upset occurs.
- Folic acid is essential for cell division, DNA synthesis, and preventing certain types of anemia.
- It's water-soluble, so excess amounts are typically excreted in urine rather than stored in the body.
Special Cases
- Women who have had a previous NTD-affected pregnancy, who are themselves affected, have a first- or second-degree relative with a NTD, or who have diabetes mellitus type 1 may be advised to take 4 mg of folic acid commencing 3 months before conception and continuing throughout the first trimester 1.
- These women should seek genetic counseling to determine their occurrence or recurrence risks, pregnancy management, and the appropriate folic acid intake for them.
From the FDA Drug Label
Except during pregnancy and lactation, folic acid should not be given in therapeutic doses greater than 0.4 mg daily until pernicious anemia has been ruled out. The recommended dose of folic acid is not explicitly stated for all cases, but it should not exceed 0.4 mg daily in certain situations, such as when pernicious anemia has not been ruled out, except during pregnancy and lactation 2.
- The dose may be higher in specific situations like pregnancy and lactation, but this information is not provided.
- Doses exceeding the Recommended Dietary Allowance (RDA) are not recommended in multivitamin preparations.
From the Research
Recommended Dose of Folic Acid
The recommended dose of folic acid varies depending on the individual's circumstances.
- For women who are planning or capable of pregnancy, the recommended dose is 400 micrograms per day 3, 4, 5, 6, 7.
- For women who have previously had a pregnancy affected by a neural tube defect, the recommended dose is 4000 micrograms per day 3, 5.
- The US Preventive Services Task Force recommends that all women who are planning or capable of pregnancy take a daily supplement containing 0.4 to 0.8 mg (400-800 µg) of folic acid 7.
Special Considerations
- Women who are taking anticonvulsant medication should consider taking a multiple vitamin containing folic acid to prevent folate lowering 6.
- The bioavailability of folate in vitamin preparations is approximately double that of dietary folate 6.
- Food fortification with folate is not recommended in some countries, as it may cause some groups to exceed the recommended upper intake level 4.
Daily Intake
- The estimated average intake of folate from foods in some countries is lower than the recommended 300 micrograms per day for adult women and men, and remarkably lower than the 400 micrograms per day recommended for pregnant and lactating women 4, 5.
- A daily dose of 650 micrograms supplemental folic acid can normalize elevated plasma homocysteine levels, which is a risk factor for cardiovascular diseases 5.