Certain vitamins for pregnant women have been found to pose potential risks.

Previous studies have already uncovered discrepancies between the stated and actual amounts of certain essential ingredients in vitamin supplements, such as folic acid, iron, and vitamins A, B6, C, and E.

Pharmaceutical and medical experts from the University of Colorado (USA) set out to evaluate prenatal vitamins for their choline and iodine dosage, which had been infrequently assessed in the past, as well as for harmful contaminants—lead, arsenic, and cadmium. The analysis examined 32 over-the-counter and 15 prescription products purchased from online stores and pharmacies in the USA between August and October 2022. The researchers’ findings were published in the American Journal of Clinical Nutrition.

The investigation revealed that in seven products, the arsenic level exceeded 2.5 micrograms per oral daily dose, the limit set by the non-profit organization United States Pharmacopeia (USP), which establishes quality standards for pharmaceuticals and dietary supplements. Two samples showed lead levels above the permissible limit, and 13 exceeded the cadmium threshold. USP standards allow their presence within 0.5 micrograms.

The researchers also found that choline, which is essential for the proper development of the brain and spinal cord in children and helps prevent congenital defects, was present in only 12 out of 47 products reviewed. Only five of these contained the amount of the substance that matched the label claim.

The recommended daily intake of choline during pregnancy and breastfeeding is 450 and 550 milligrams, respectively. Clinical trials have shown that increased choline consumption during the prenatal period correlates with benefits for children's brain development.

Iodine is also crucial for the proper growth and development of the fetus. Out of 25 iodine-containing products examined, only four contained the amount indicated on the label, while most others fell short. The recommended iodine intake for pregnant and breastfeeding women is 220 and 290 micrograms per day.

Commenting on the results, the authors noted that many pregnant women take vitamins and minerals to support their health and the development of their child. However, the study revealed that choline and iodine are not included in all such products, despite the importance of these substances for expectant mothers and their children. Furthermore, they are often present in lower concentrations than stated by manufacturers.

The presence of toxic impurities, particularly cadmium, in the examined products also raised concerns among the researchers. Overall, the analysis highlighted a significant gap between the label claims and the actual composition of prenatal vitamin supplements. The scientists urged for stricter oversight by regulatory bodies in this area.