American Association of Clinical Endocrinologists (AACE)/ American College of Endocrinology (ACE) Initiatives Highlight the Importance of Improved Iodine Nutrition

By Elizabeth Pearce, MD, FACE

Iodine is a critical micronutrient found in the diet that is needed in sufficient quantities not only to ensure optimal health, but also to make thyroid hormone, which is vital for normal brain development: low iodine intake in pregnant women can lead to brain damage in their children. Iodine deficiency affects 1.92 billion people worldwide and is the leading preventable cause of mental retardation.

Pregnant women need to increase their iodine intake. Women who are breastfeeding also need higher iodine intake, since iodine is transported into breast milk, where it is important for infant nutrition. Pregnant women need 220 micrograms iodine every day. Breastfeeding mothers need 290 micrograms daily. These levels are higher than the 150 micrograms daily recommended for most adults.

Most people in the United States get enough iodine in their diets. However, studies over the last decade have shown that iodine intake is low in pregnant women. Although urine measurements can be used to estimate the iodine status of large groups, there is currently no test that can tell whether an individual person is getting enough iodine.

Sources of Iodine

Although dairy foods are currently an important source of iodine in the U.S., most sources of iodine in foods can be hard to identify. Iodine is not listed on package labels in the U.S., and typical iodine amounts in foods are quite variable. While adding iodine to salt has been the mainstay of global efforts to improve iodine nutrition, salt iodization has never been required in the U.S. Most U.S. commercial food processors do not use iodized salt. And although iodine is especially important in pregnancy, only half of the prenatal vitamin brands sold in the US contain iodine.

AACE/ACE Recommendations

AACE/ACE recommend that all U.S. women who are pregnant, breastfeeding or planning a pregnancy should take a daily multivitamin containing 150 micrograms of iodine. Ideally, all prenatal vitamins sold in the U.S. should contain iodine.

Petition to the Dietary Guidelines for Americans Committee

To that end, AACE/ACE recently teamed with the American Thyroid Association, the Endocrine Society, the International Council for the Control of Iodine Deficiency Disorders Global Network, and the Teratology Society to offer suggestions to the Dietary Guidelines for Americans committee, which provides the basis for all federal food and nutrition policy and education initiatives. These guidelines are updated by the U.S. Department of Agriculture (USDA) and the U.S. Department of Health and Human Services every five years. The next update is due in 2015.

The current guidelines do not mention iodine. The societies recommended that pregnant women and women of childbearing age should eat a varied diet rich in iodine-containing foods, such as fish and milk, and should choose iodized salt over non-iodized salt. The collective groups also recommended that women who are pregnant, breastfeeding or planning a pregnancy should take a daily prenatal vitamin that contains 150 micrograms of iodine.

The New England Chapter of AACE has recently taken this initiative a step further by calling for the help of local health insurers, asking them to pay only for prenatal vitamins that include 150 micrograms iodine daily. AACE/ACE believe that insurance policies encouraging the use of iodine-containing vitamins could help to protect the health of women and children.

AACE/ACE are working nationally and regionally to make sure that women and their babies are getting the iodine they need for thyroid health and brain development.

Dr. Elizabeth Pearce is an Associate Professor of Medicine at Boston University School of Medicine. She received her undergraduate and medical degrees from Harvard and a master’s degree in epidemiology from the Boston University School of Public Health. She completed her residency in internal medicine at Beth Israel Deaconess Medical Center and her fellowship in endocrinology at the Boston University Medical Center. Her research interests include the sufficiency of dietary iodine in the U.S., thyroid function in pregnancy and the effects of environmental thyroid disruptors.