by Mommy MD Guide Rallie McAllister, MD, MPH
If you’re thinking about getting pregnant, you may want to increase your intake of iodine-rich foods. Iodine is a mineral that is essential to good health, not only for moms-to-be, but also for their unborn babies. Recent research reveals that many women of reproductive age aren’t getting sufficient iodine to ensure a healthy pregnancy.
In the typical American diet, iodized table salt is the primary source of iodine. This fortified table salt was introduced in the U.S. in the 1920s to help reduce the epidemic of thyroid goiter caused by low iodine intake in some parts of the country. Although its high sodium content contributes to a number of health concerns, including high blood pressure and kidney disease, the iodine in this type of salt still serves a very important purpose.
The mineral is essential for proper production of thyroid hormones. Thanks to the widespread use of iodized table salt, thyroid goiters are far less common in the U.S. today than they were a century ago. But as more people—including pregnant women—shy away from salt in an effort to reduce sodium intake, iodine deficiency is once again becoming a concern. Recent research suggests that Americans are consuming significantly less iodine than they did 30 years ago. Data from the 2001-2006 National Health and Nutrition Survey (NHANES) indicates that urinary iodine concentrations among Americans have decreased by 50 percent since the 1970s.
While a teaspoon of iodized table salt typically offers roughly 400 micrograms of iodine, more than enough to meet the Recommended Dietary Allowance (RDA) for the mineral, the content may vary among brands. According to a report published in the journal Environmental Science and Technology, 53 percent of iodized salt samples tested in 2008 contained less than the FDA-recommended level of this key nutrient.
Even if you regularly consume lots of salty, processed foods, there’s no guarantee that you’re getting enough iodine for good health. Although a diet rich in processed foods typically is loaded with sodium, it doesn’t necessarily provide adequate levels of iodine, since manufacturers may prepare foods with non-iodized salt.
Adequate iodine intake is important for good health at every stage of life. It’s especially critical for pregnant women, since a deficiency of the mineral in pregnancy can lead to mental retardation in babies. Even mild deficiency in fetal iodine can cause lasting impairment in cognitive ability.
Iodine is required for normal brain development in newborn infants and children. A growing body of scientific evidence supports a link between iodine deficiency and attention deficit disorders. The RDA for iodine is 110 micrograms for infants aged six months and younger, and 130 micrograms for babies aged seven to 12 months. Children aged one to eight years need at least 90 micrograms iodine a day, and those aged nine to 13 years need at least 120 micrograms.
For most healthy adults, the RDA for iodine is 150 micrograms. Pregnant women need more of the mineral, with an RDA of 220 micrograms.
Because most of the earth’s iodine is found in oceans, most types of seafood are excellent sources of the mineral. In addition to saltwater fish and shrimp, foods rich in iodine include sea vegetables, such as kelp, wakame and nori, the seaweed used to make sushi. Certain cheeses, including cheddar and cottage cheese, are good sources of iodine. Some processed foods, including bread and breakfast cereal, are fortified with the mineral.
Cutting back on your salt consumption is an excellent way to improve your health, as long as you don’t sacrifice your iodine intake in the process. If you’re thinking about becoming pregnant, your iodine intake is more important than ever.