Recommended daily intake of folic acid
Pro Research Analysisby 
Searched over 200M research papers
Recommended Daily Intake of Folic Acid: Global Guidelines and Key Populations
General Adult Recommendations for Folic Acid Intake
Most health organizations recommend a daily folic acid intake of 300–400 µg for adults, with specific emphasis on women of childbearing age to help prevent neural tube defects (NTDs) in newborns Bree1997Gomes2015. In Europe, the recommended intake for adults generally ranges from 200–300 µg/day for men and 170–300 µg/day for women, while the World Health Organization (WHO) and the majority of countries advise a supplement of 400 µg/day for women planning pregnancy or in the early stages of pregnancy Bree1997Gomes2015.
Folic Acid Intake for Women of Childbearing Age and Pregnancy
The Institute of Medicine (IOM), US Centers for Disease Control and Prevention (CDC), and WHO all recommend that women capable of becoming pregnant consume 400 µg of folic acid daily, starting before conception and continuing through at least the first trimester, to prevent NTDs Tinker2010Gomes2015Crider2018+1 MORE. This recommendation is widely supported by evidence showing that this intake level is effective for reducing NTD risk, and higher doses do not provide additional benefit for most women Crider2018Patti2022Chitayat2015.
For women with a previous pregnancy affected by NTDs or other high-risk factors (such as certain medical conditions or medications), a much higher dose—up to 4,000–5,000 µg (4–5 mg) per day—is recommended during the periconceptional period Bree1997Gomes2015Chitayat2015.
Upper Intake Levels and Safety Considerations
The tolerable upper intake level (UL) for folic acid in adults, including pregnant and lactating women, is set at 1,000 µg (1 mg) per day to avoid potential adverse effects, particularly in individuals with vitamin B12 deficiency Turck2023Patti2022Rose2021+1 MORE. Most people do not exceed this level through diet alone, but those taking high-dose supplements may surpass the UL, which is not recommended unless specifically advised by a healthcare provider for high-risk situations Turck2023Patti2022Rose2021+1 MORE.
Actual Intake Patterns and Supplement Use
Despite recommendations, only about 24% of US women of childbearing age meet the 400 µg/day intake, with supplement use being the strongest predictor of adequate intake Tinker2010Crider2018. In countries with mandatory folic acid fortification, most women achieve sufficient folate status, but many prenatal supplements contain 1,000 µg, leading to intakes above the UL for most pregnant women—without added benefit for NTD prevention Patti2022Rose2021. Experts suggest that prenatal supplements should ideally contain 400 µg to ensure optimal and safe intake Patti2022Rose2021.
Dietary Sources and Fortification
A healthy diet rich in vegetables, fruits, and cereals is encouraged to help meet folate needs, but supplementation is still recommended for women of reproductive age due to the difficulty of achieving optimal intake through diet alone Bree1997Gomes2015Dary2009. Fortified foods, such as enriched cereal grain products, also contribute significantly to folic acid intake, especially in countries with mandatory fortification policies Crider2018Yang2009.
Conclusion
The consensus across global health organizations is that adults should aim for 300–400 µg of folic acid daily, with women of childbearing age and those planning pregnancy advised to take a 400 µg supplement daily to prevent neural tube defects. Higher doses are reserved for women at increased risk. Exceeding the upper intake level of 1,000 µg/day is not recommended for the general population, as higher intakes do not provide additional benefits and may pose risks. Achieving recommended intake often requires a combination of diet, fortified foods, and supplements, with a focus on not exceeding safe upper limits.
Sources and full results
Most relevant research papers on this topic