Lead in Food: New Study Shows High Lead Levels in Prenatal Vitamins

What Happened

A new study by Gardener, Bowen (of Clean Label Project), and Callan of 156 prenatal vitamins, 9 prescription prenatal supplements and 19 folate/folic acid supplements revealed disturbingly high levels of lead and—to a lesser extent—cadmium.

In the commercially available prenatal vitamins, lead was above the LOQ in tablets (N=56), capsules (N=45), caplets (N=5), and powders (N=5). All products were less than the LOQ for gummies (N=21) and soft gels (N=18).¹[i] The study did not reveal the names of the products evaluated.

Study Results	Commercially available prenatal vitamins	Prescription prenatal vitamins	Folic acid / folate supplements
No. of products tested	156	9	19
Lead
Average	79 ppb	91 ppb	< LOQ
Maximum	900 ppb	2,380 ppb	260 ppb
% < LOQ	17%	22%	53%
No. > 0.5 µg/serving	23 (15%)	3 (33%)	None
Cadmium
Average	45 ppb	93 ppb	< LOQ
Maximum	485 ppb	203 ppb	35 ppb
% < LOQ	27%	22%	79%
No. > 4.1 µg/serving	None	None	None
µg = micrograms ppb = parts per billion = µg/kg LOQ = Limit of Quantification (varied from 5–19 ppb based on sample matrices) California Proposition 65 warning level is 0.5 ug/day for lead and 4.1 ug/day for cadmium

Why it Matters

Prenatal lead exposure presents significant risks to both the pregnant person and the fetus. Even low level exposures are associated with subtle harms that can last a lifetime.

Until recently, prenatal vitamins were not considered a significant source of lead exposure. That changed in 2018 with a study of 26 products with additional studies of 6 products in 2023 and 9 products in 2021.

Those studies prompted California Senator Weber Pierson, a board-certified obstetrician/gynecologist in San Diego, to introduce SB 646 to require manufacturers to test each batch of prenatal vitamins they sell in the state for arsenic, cadmium, lead, and mercury. Starting January 1, 2027, the companies would be required to disclose the test results on their website and add a QR code to their label to make it easy for consumers to access the information.

This bill is similar to the approach successfully used for baby food in California’s AB 899 in 2023, with companies making the results publicly available for foods made in 2025. Unleaded Kids’ preliminary review of the data suggests that companies significantly reduced lead levels in their products in 2024 in anticipation of making the information publicly available. More to follow on this in later blogs.

The American Council of Obstetricians and Gynecologists District IX (ACOG), Environmental Working Group (EWG), and Unleaded Kids are sponsoring the legislation.

Our Take

With 184 products evaluated, the new study is sufficiently large enough to demonstrate that levels of lead in prenatal vitamins varied widely, ranging from 20% being less than the LOQ to a shocking high of 2,380 ppb in a prescription product. Cadmium levels also varied widely, though somewhat less so.

The wide variation of products with similar ingredients indicates that some manufacturers are carefully managing the supply chains for their ingredients to reduce lead and cadmium contamination while others may be doing little.

We need to drive lead and cadmium contamination down. With the tumult at the federal level, FDA cannot be expected to do much, especially with its flawed action level approach on lead in baby food focused on only the highest levels.

For that reason, states need to lead. Sen. Weber Pierson’s SB 646 is doing that by:

• Empowering pregnant people with sufficient information to make choices about the prenatal vitamins they buy; and
• Creating marketplace incentives for companies to compete for the lowest level of contamination.

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1. All products were < LOQ for liquids (N=4), liquid gels (N=1), and chews (N=1). ↩︎