Iodine and Breastfeeding

Risks of deficiency

Iodine is a vital component of thyroid hormones thyroxine (T4) and triiodothyronine (T3). Thyroid hormone levels affect proper fetal and infant growth and neurological (brain) development. Breastfed babies get their iodine from breastmilk. Therefore, breastfeeding mothers need to get enough iodine.

Some women are at a greater risk than others for developing iodine deficiency while breastfeeding. These include women who:

• Smoke cigarettes.
• Do not regularly consume dairy products or seafood.
• Do not use iodized salt.
• Eat foods containing goitrogens.

Goitrogens can affect how well the thyroid gland makes thyroid hormones. Goitrogens are in foods such as brussel sprouts, kale, cabbage, cauliflower, radishes, and broccoli.

Breastfeeding, iodine, and infant health

Infants usually get enough iodine from breast milk. Although breast milk contains iodine, concentrations can vary based on maternal iodine levels. If a pregnant or breastfeeding woman is iodine deficient, the fetus or infant may be at risk for iodine deficiency and associated cognitive and psychomotor impairments.

The recommended dietary allowance (RDA) is the average amount of a vitamin or mineral that meets the daily nutrient needs of nearly all healthy people. The iodine RDA is higher for women when they are pregnant or breastfeeding to support proper fetal or infant growth and neurological development.

Dietary recommendations

The diet of pregnant or breastfeeding women may not contain enough iodine to meet the RDA. Therefore, the American Thyroid Association and the American Academy of Pediatrics recommend that pregnant or breastfeeding women take a multivitamin or prenatal supplement every day containing 150 micrograms (µg) of iodine.

Not all multivitamin and prenatal supplements contain 150 µg of iodine. Check the nutrition label or speak with a health care provider about whether multivitamin supplements or prenatal vitamins contain enough iodine.

Learn more

• Why Micronutrients Matter
• Micronutrient Facts
• Iodine Fact Sheet for Consumers—National Institutes of Health
• Iodine Fact Sheet for Health Professionals—National Institutes of Health
• Iodine Supplementation for Pregnancy and Lactation—U.S. and Canada: Recommendations of the American Thyroid Association
• Iodine Deficiency, Pollutant Chemicals, and the Thyroid: New Information on an Old Problem—American Academy of Pediatrics
• Recommendations on Iodine Nutrition During Pregnancy and Lactation—American Academy of Pediatrics
• Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc—National Academy of Medicine