Truth About Iodized Salt continued...
Until nearly five years ago, Americans who got dairy, bread, and meat in their diets got plenty of iodine, he explains. Machines used in production were cleaned with an iodine disinfecting solution, so some iodine ended up in dairy, bread, meat products. That ended when companies quit using iodine disinfectant.
Iodized salt is rarely found in canned, frozen, or boxed food, says Maberly. French fries and other snack foods mostly contain regular salt -- not iodized salt.
In fact, Americans now get one-third less iodine than they once did, he notes.
Both newborns and toddlers are affected by iodine deficiency. A recent study showed lower IQ scores among children with mild iodine deficiency -- proof that the problem exists in developed countries, writes researcher Piedad Santiago-Fernandez, MD, an endocrinologist at the Complejo Hospitalario Carlos Haya in Malaga, Spain.
It's true, says Michael Karl, MD, an endocrinologist with the University of Miami School of Medicine. "You can certainly see even subtle changes in iodine can affect IQ," Karl tells WebMD. "Iodine is critical in the first years of life, extraordinarily important up to 3 or 5 years of age."
Children in financially stressed families are likely at highest risk. They rarely take multivitamins, he tells WebMD. "Iodine deficiency is not an epidemic yet, but it's serious enough that it should be watched."
Sea salt and most salt substitutes are not iodized. Unless fruits and vegetables are grown in iodine-rich soil, they will not contain iodine. Restaurants usually order salt in bulk, and often it's not iodized salt.
However, anything from the sea - such as seaweed (kelp) or fish -- can be a good source of iodine, says Maberly. A cup of cow's milk contains nearly 100 micrograms of iodine. Some breads contain iodine, but not all.
The normal requirement for iodine, according to World Health Organization standards: Adults need 150 micrograms a day. Women trying to get pregnant should increase their intake to 200 to 300 micrograms a day.
"We certainly should make pregnant and lactating women aware of this deficiency," says Karl. "I don't think most primary care doctors are aware of it."