Folate (Vitamin B9)
Folate is a water-soluble B vitamin involved in one-carbon metabolism, DNA and RNA synthesis and amino-acid metabolism. Folic acid is a synthetic form used in many supplements and fortified foods.
What it does in the body
- Required for DNA and RNA synthesis
- Participates in amino-acid metabolism
- Supports normal cell division and blood-cell formation
Daily reference intake
In the U.S. DRI system, adults need 400 µg DFE/day; pregnancy increases the requirement to 600 µg DFE/day and lactation to 500 µg DFE/day.
What can deficiency look like?
- Megaloblastic anemia
- Weakness or fatigue
- Changes in the tongue or oral mucosa can occur
- Low maternal folate status around conception increases neural-tube-defect risk
Who may be at higher risk?
- People with poor dietary intake or alcohol-use disorder
- People with malabsorptive disorders
- People with increased requirements such as pregnancy
- Some medicine users, depending on the drug
Food sources
A varied diet is the first place to look for nutrients. Availability and nutrient content can vary by food, preparation and country.
Food-source note: Natural food folate and folic acid used in supplements/fortification differ in bioavailability. Dietary Folate Equivalents (DFE) are used to account for this difference.
Absorption & practical context
Folic acid taken with food or supplements is generally more bioavailable than naturally occurring food folate.
Important interactions
- Methotrexate and some anti-seizure medicines interact with folate pathways
- Large amounts of folic acid can correct anemia caused by B12 deficiency while neurological injury continues
Safety and context
The upper intake level applies to folic acid from supplements and fortified foods, not naturally occurring food folate. High intake should not be used to self-treat anemia before B12 deficiency has been considered.
Scientific sources
NIH Office of Dietary Supplements — Folate ↗ EU Register of Nutrition and Health Claims ↗Products whose current label lists this nutrient
The entries below are based on current manufacturer label information for the selected market. Compare the stated amount per daily serving and read the official product page before purchasing.