Vitamin makers are being strongly urged to use only potassium iodide and not other sources of iodide for their prenatal products. Boston University School of Medicine researchers have found that potassium iodide is the most efficient way for expectant mothers to receive iodine.
Researchers compared over 200 prescription and nonprescription prenatal multivitamins that are sold in the United States. Of these, over 100 contained iodine. The iodine content most often would come from one of two sources: kelp and potassium iodide. In tests that isolated the iodine content of the multivitamins, those that contained potassium iodide had approximately 75% of the amount as stated on the product’s label. While this is not exactly ideal, it is also in no way inconsistent. In contrast, the products using kelp for iodine had a very large range of actual iodine content, and the variation therein was much more unpredictable: researchers found levels ranging from 33 to 610 micrograms per daily dose. Iodine can degrade over time, and this can have some affect on quantities found in the study, but it is obvious that potassium iodide appears to be the more consistent of the two primary sources for iodine.
"The American Thyroid Associated has recommended that women receive prenatal vitamins containing 150µg of iodine daily during pregnancy and lactation. However, the iodine content of prenatal vitamins is not mandated in the United States," said Dr. Elizabeth Pearce, lead author of the study. While the ATA has recommended 150 micrograms a day, other sources have the amount at slightly elevated levels. The Institue of Medicine, for example, recommends that pregnant and nursing mothers receive 220 to 290 micrograms of iodine a day. Iodine itself is commonly added to table salt, and it can be found in dairy, seafood, and bread products.
The amount of iodine that a mother receives plays a crucial role in promoting correct thyroid function for fetuses and breastfed infants. Thyroid function is crucial for correct neurocognitive development, and iodine deficiency is the leading cause of preventable mental handicap. At present, more that 2.2 billion people worldwide are iodine deficient. Even slight iodine deficiency can cause problems in development, affecting hearing and speech, as well as mental development and growth.
Eureka Alert!: BUSM researchers encourage use of potassium iodide