Researchers from Boston University School of Medicine (BUSM) are strongly encouraging prenatal vitamin manufacturers to use only potassium iodide and not other sources of iodine in their products.
According to the researchers, potassium iodide is the best way to ensure that prenatal vitamins given to expectant mothers receive 150µg of supplemental daily iodine as recommended by the American Thyroid Association. The researchers' recommendation appears as a research letter in the February 26th issue of the New England Journal of Medicine .
Normal thyroid function in fetuses and breastfed infants, which is dependent on sufficient maternal dietary intake of iodine, is crucial for normal neurocognitive development. Iodine deficiency affects more than 2.2 billion persons and is the leading cause of preventable mental retardation worldwide. Even mild iodine deficiency may have adverse effects on the cognitive function of children.
Using the Internet, the BUSM researchers identified 127 nonprescription and 96 prescription prenatal multivitamins currently marketed in the U.S. Of these multivitamins, 114 (87 nonprescription and 27 prescription) contained iodine. According to the label, 89 percent contained 150µg or more of iodine per serving. The iodine was in the form of kelp in 42 multivitamins, potassium iodide in 67, or another ingredient in five.