From the Guidelines
The recommended dose of folic acid for women planning or capable of pregnancy is 0.4 to 0.8 mg (400 to 800 μg) per day, as it has been shown to reduce the risk of neural tube defects 1. When considering the dosage, it's essential to note that most organizations recommend higher doses for women who have had a previous pregnancy affected by neural tube defects or those taking certain antiseizure medicines.
- The USPSTF found convincing evidence that supplements containing 0.4 to 0.8 mg of folic acid in the periconceptional period reduce the risk for neural tube defects 1.
- Good evidence from randomized trials suggests that a multivitamin with 0.8 mg of folic acid reduces the risk for neural tube defects, while observational studies report a reduction in neural tube defects in women taking a supplement with 0.4 mg of folic acid 1.
- It is crucial to start folic acid supplementation at least 1 month before conception and continue daily supplements through the first 2 to 3 months of pregnancy, as most studies indicate this timing is necessary to reduce the risk of neural tube defects 1.
- Women should be advised to take folic acid supplements, even if they are not planning a pregnancy, as 50% of pregnancies in the United States are unplanned 1.
- The effective amount of additional folic acid needed may vary depending on the level of food fortification, but evidence suggests that most women in the United States are not ingesting fortified foods at a level thought to provide optimal benefit 1.
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 to exceed 0.4 mg daily in non-pregnant and non-lactating patients, until pernicious anemia has been ruled out 2.
From the Research
Folic Acid Dose Recommendations
The recommended dose of folic acid varies depending on the individual's risk factors and health status.
- For women capable of becoming pregnant, the recommended dose is 400 micrograms per day to prevent neural tube defects (NTDs) 3, 4, 5.
- For women who have previously had an NTD-affected pregnancy, the recommended dose is 4000 micrograms per day beginning at least 1 month before conception and continuing through the first trimester 3.
- For women at high risk of NTDs, the recommended dose is 4 mg per day 4.
Food Fortification
Food fortification with folic acid is also recommended to prevent NTDs.
- A fortification program that delivers 400 micrograms of folic acid daily to women would protect against NTDs, but may result in unnecessarily high exposure for many people 6.
- Delivery of 200 micrograms daily is also effective against NTDs and safer for the general population 6.
- A dose of 100 micrograms daily, taken continually as it will be in fortified food, will also produce an important decrease in NTDs 6.
Periconception Multivitamin Supplementation
Periconception multivitamin supplementation containing a physiological dose of folic acid (0.5 to 0.8mg) may be more effective in reducing the occurrence of the first NTD and other congenital abnormalities than folic acid alone 7.
- This type of supplementation may also reduce the occurrence of recurrent NTDs and other congenital abnormalities such as urinary tract and cardiovascular defects, and congenital limb deficiencies 7.