Perspective: Time to Resolve Confusion on Folate Amounts, Units, and Forms in Prenatal Supplements

Adv Nutr. 2020 Jul 1;11(4):753-759. doi: 10.1093/advances/nmaa017.


Folate-containing prenatal supplements are commonly consumed in the United States, but inconsistencies in units of measure and chemical forms pose challenges for providing authoritative advice on recommended amounts. New regulations require folate to be declared as micrograms of dietary folate equivalents (DFE) on product labels, whereas intake recommendations for reducing the risk of neural tube defects (NTDs) and the Tolerable Upper Intake Level are expressed as micrograms of folic acid. Today, >25% of prenatal supplements contain folate as synthetic salts of L-5-methyltetrahydrofolate (L-5-MTHF), but recommendations do not include this form of the vitamin. Harmonizing units of measure and addressing newer forms of folate salts in intake recommendations and in the prevention of NTDs would resolve the confusion.

Keywords: DRIs; L-5-methyltetrahydrofolate; folate; folate Daily Values; folate labeling; folate recommendations; prenatal supplements.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Dietary Supplements
  • Female
  • Folic Acid*
  • Humans
  • Neural Tube Defects* / prevention & control
  • Pregnancy
  • United States
  • Vitamins


  • Vitamins
  • Folic Acid