The voluntary guideline for CRN members echoes recommendations made last summer by the American Academy of Pediatrics that breastfeeding mothers and women of childbearing age take a daily supplement with 150 mcg of iodide to support healthy cognitive development in children.
“Many women of reproductive age in the United States are marginally iodine deficient,” which can hinder the production of thyroid hormone necessary for brain development in children, the AAP explains in the policy statement published in the journal Pediatrics in June 2014.
The American Thyroid Association and the National Academy of Sciences also recommend lactating women consume 240 mcg of iodide daily, which generally requires a supplement of 150 mcg of iodide to achieve, AAP notes.
“For the iodine guideline, the medical community is in agreement of the importance of prenatal multivitamins to provide the required amount of iodine. CRN and its members follow the science and so do CRN guidelines,” said Duffy MacKay, senior vice president of scientific and regulatory affairs at CRN.
He added that “in preparation for compliance, CRN staff takes the time to educate its members on why we develop these guidelines and we take the time to present the science that supports these recommendations.”
Filling a gap
CRN’s recommended guideline should help more women reach the medical community’s daily goal by closing the gap between the amount of iodide needed and the amount currently in supplements.
The AAP noted that even though in the U.S. “most pregnant and lactating women take supplements, only 15% to 20% take supplements that contain any iodine.”
Indeed, only half of prenatal supplements sold in the U.S. and tested by researchers in 2009 were formulated with iodine, and of those that included the ingredient only 45% met the minimum amount of 150 mcg recommended by CRN, according to a study published in 2009 in the New England Journal of Medicine. The study sampled 223 prescription and nonprescription prenatal supplements sold in the U.S. in 2009.
Since the study was published, most major prenatal supplement manufacturers have formulated their products to include at least 150 mcg of iodine or are in the process of doing so, a CRN spokeswoman said. But, she added, a goal of the guideline is to encourage all manufacturers to follow suit.
Source of iodine is flexible for CRN
Deviating from the AAP and other medical associations, CRN’s guideline says the source of the iodine does not matter as long as it is “safe and suitable” and “used in accordance with current good manufacturing practice (cGMP) regulations … which will ensure that the product consistently meets label claim.”
The AAP says in its policy statement that iodine from potassium iodide is ideal.
It bases this recommendation on the NEJM study’s finding that the measured iodine content is about 76% of the total potassium iodide content labeled in supplements, which was far higher than the amounts of iodine from kelp and other ingredients.
Processed foods to blame for deficiency
The AAP blames the widespread iodine deficiency in the U.S. on the use of noniodized salt to make many processed foods, the consumption of which has increased and prompted most people to use less iodized salt.
Convincing food manufacturers to help reduce the deficiency by switching to iodized salt is unlikely, making supplements more important, the AAP notes. Many food manufacturers do not want to use iodized salt “for fear that taste or other characteristics of the processed foods would be altered,” according to the AAP’s policy.