Pregnant women are encouraged to take an supplement containing iodide in order to protect their baby's brain health. 

"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," Dr. Jerome Paulson told Reuters. "Women in the early part of the pregnancy may not realize they're pregnant."

A great deal of table salt in the United States contains salt fortified with iodide, but highly processed foods do not contain fortified salt. 

About one-third of all U.S. women are believed to be iodide deficient; only about 15 percent of women take a supplement. Women are urged to get at least 290 micrograms of iodide per day. 

"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."

Women should also be regularly tested for iodide deficiency, especially if they are vegan or don't consume seafood. 

"Obviously iodine is critical to the fetal and child brain," Dr. Loralei Thornburg told Reuters. "Therefore having a diet that's rich in iodine is critical."

"Although many women are largely iodine deficient, most women do get iodine in the (form) of food," she said. "This isn't something women should freak out about just yet."

Pregnant and lactating women should also avoid both nitrate and thiocyanate, which can interfere with the body's ability to hormonally process iodide. Nitrate can be found in contaminated well water while thiocyanate is present in cigarette smoke and vegetables such as broccoli, cauliflower, and cabbage. Women rarely eat enough of these vegetable for it to be a concern. 

"I think people can have some control over their exposure to tobacco smoke, but they may not even be aware of the perchlorate or other chemicals in the water," Paulson said.