Iodine content of frequently used prenatal and adult multivitamins in Switzerland.

Background: Iodine is essential for the biosynthesis of thyroid hormones, which are crucial for intrauterine growth and fetal neurocognitive development. Iodine requirements increase during pregnancy and lactation. The World Health Organization and the Swiss Confederation recommend a total daily iodine intake of 250 µg of iodine during preconception, pregnancy and lactation.