Health experts from the American Academy of Pediatrics (AAP) urge pregnant and lactating women to take iodine supplements, as many women in this group are marginally deficient in iodine, an element that is crucial for the proper bone and brain development of babies.

In the policy statement "Iodine Deficiency, Pollutant Chemicals and the Thyroid: New Information on an Old Problem" published in the journal Pediatrics on May 26, pediatricians from the AAP said that it is important that pregnant women and breastfeeding mothers supplement their diet with iodine as they may not be getting enough of this element from their diet.

The researchers also promoted the use of iodized salt, as many Americans consume processed foods and these contain salt that is not iodized. They also advised against exposure to certain environmental pollutants such as nitrate, which is present in contaminated well water, perchlorate, which can be found in public drinking water systems, and thiocyanate , which is present in cigarette smoke and in some vegetables including cabbage, cauliflower and broccoli, as these chemicals can disrupt iodine from being processed into hormones.

"Many women of reproductive age in the United States are marginally iodine deficient, perhaps because the salt in processed foods is not iodized," the researchers wrote. "Iodine deficiency, per se, can interfere with normal brain development in their offspring."

Iodine deficiency can have a negative effect on the brain development of babies as iodine produces thyroid hormones that play a role in the brain development of children before and after birth. Severe iodine deficiency in pregnant women could also lead to mental retardation, stunted growth and delayed sexual development of their offspring.

As many as a third of pregnant women in the U.S., however, are iodine deficient, and only about 15 percent of these women take iodine supplements. Worse, their supplements may not even contain sufficient amounts of iodide as supplements may be labeled inaccurately. AAP experts advised pregnant women and lactating women to take supplements that contain 150 micrograms of iodide per day.

Jerome Paulson, from the American Academy of Pediatrics Council on Environmental Health, which authored the policy statement, said that women who are in childbearing age, and not just pregnant and lactating women, should be on guard against iodine deficiency as many women in the early stage of pregnancy are not aware that they are pregnant.

"Women who are childbearing age need to pay attention to this topic as well, because about half of the pregnancies in the U.S. are unplanned," Paulson said. "Women in the early part of the pregnancy may not realize they're pregnant."