Abstract
Objectives
Most prenatal supplements available in the US contain synthetic folic acid. We compared the labeled amounts of folic acid in prenatal supplements with: 1) the Recommended Dietary Allowance (RDA) of 360 mcg and Tolerable Upper Intake Level (UL) of 1000 mcg for pregnant women established by National Academies of Science, Engineering and Medicine's Food and Nutrition Board (FNB) and expressed as synthetic folic acid from supplements and fortified foods; 2) current population-based Daily Values (DV) used for labeling dietary supplements and established by the US Food and Drug Administration (FDA); 3) FDA criteria for making a neural tube defects health claim on prenatal supplement labels; and 4) 2009/2016 recommendations for the prevention of neural tube defects by the US Preventive Services Task Force (USPSTF). In 2016, the FDA revised its DV to 600 mcg DFE folate (360 mcg folic acid) to reflect amounts consistent with the RDAs. This new DV is lower than the pre-2016 DV of 800 mcg from food and supplement sources and the 800 mcg level to make a health claim.
Methods
We reviewed the synthetic folic acid content as declared on prenatal supplement labels sold with and without a prescription, using data in the Dietary Supplements Label Database (DSLD) (website: https://dsld.nlm.nih.gov/dsld/) and DailyMed (website: https://dailymed.nlm.nih.gov/dailymed/index.cfm).
Results
The many recommendations for folate versus folic acid are often unclear (e.g., Dietary Folate Equivalents vs. mcg folic acid). Amounts ≥ 800 mcg folic acid per serving, the prior DV, were present on 99% of 79 prescription and 91% of 121 nonprescription labels reviewed. 94% of the prescription and 16% of nonprescription prenatal supplements were labeled at 1000 mcg per serving, and none (0%) of the prescription and 74% of the nonprescription were labeled at 800 mcg. These labeled amounts (from supplements alone) were higher than the USPSTF recommended daily intake of 400 to 800 mcg and the current DV and RDA values.
Conclusions
The DV, UL, the criterion for making a health claim on prenatal supplement labels, the USPSTF recommendations, and the units used for expressing folate and folic acid recommendations need to be harmonized and clarified.
Funding Sources
Office of Dietary Supplements, NIH.
Impact of Folic Acid Fortification of the US Food Supply on the Occurrence of Neural Tube Defects
