Prenatal vitamins may contain dangerous levels of lead and arsenic: study

Some prenatal vitamins contain “relative” levels of toxic heavy metals, while others lack key nutrients needed for a healthy pregnancy, a shocking new study has found.

Researchers at the University of Colorado Anschutz Medical Campus tested 47 prenatal vitamins—32 over-the-counter and 15 prescription—for levels of choline and iodine, and also tested for arsenic, lead and cadmium.

Seven products had arsenic levels above USP purity limits, two had too much lead, and 13 had too much cadmium. Cadmium poisoning can cause chills, fever, and muscle aches, and chronic exposure can cause damage to the kidneys, bones, and lungs.

“The presence of contaminants, especially cadmium, was concerning,” said Laura Borgelt, first author of the study.

Borgelt’s team also found a gap between what’s on labels and what’s actually in products.

The recommended amount of choline, which supports baby’s brain and spinal cord development and helps prevent birth defects, is 450 milligrams per day during pregnancy and 550 mg per day during lactation.

The researchers found that only 12 of 47 products (about 26%) listed choline, and only five products contained the amount of choline promised on the label.

“During pregnancy, many women rely on prenatal vitamins and minerals to support their health and the development of their baby,” Borgelt said. “Among the most important nutrients for fetal development are choline and iodine.”

Iodine is necessary for the production of thyroid hormones, which are critical for proper growth and development of the fetus. The recommended iodine intake is 220 mcg per day for pregnant women and 290 mcg per day for nursing mothers.

Of the 25 products labeled as containing iodine, only four contained the amount of iodine stated on the label.

The results were published this week in the American Journal of Clinical Nutrition.

Borgelt proposes “stricter regulatory oversight” of prenatal vitamins, echoing a 2023 federal government report calling for more authority for the U.S. Food and Drug Administration to oversee dietary supplements due to discrepancies between what is on pregnancy supplement labels and what is in products.

Most prenatal vitamins are sold over the counter, meaning the FDA does not regulate them as strictly as medications.

Despite these concerns, study authors still recommend taking prenatal vitamins during pregnancy. Consumers should double check the ingredients on the label or consult their doctor to choose the best supplement.