What’s Up With Iodine?
Alexis Cascone MS, RD, CD-N, CLC
Iodine is a mineral found naturally in seafood, seaweed, and dairy products. It can also be added to salt however many salts such as sea salt do not contain iodine in them. For the body to make thyroid hormones it needs iodine, an iodine deficiency can alter the thyroid hormone synthesis. Thyroid hormones are important for proper bone and brain development during pregnancy and infancy.
Iodine Requirements
Iodine requirements during infancy is high as there is elevated thyroid hormone turnover. Breastfed infants rely on iodine from breastmilk which is determined by maternal iodine intake. Based on the Recommended Daily Allowance (RDA), a woman who is not pregnant or breastfeeding, she would need 150mcg per day of iodine. During pregnancy iodine needs increase to 220mcg and increase again if breastfeeding to 290mcg. (1) Some prenatal vitamins have started to include iodine in their supplements due to the popularity of salts that do not contain iodine in them such as sea salt. If the prenatal contains iodine, most of the time it won’t meet 100% of a woman’s needs in postpartum. The variety of foods within a woman’s diet is important to meet her body’s evolving nutrient demands.
According to the WHO, a median urinary iodine concentration of 150-249mcg/L indicates adequate iodine during pregnancy. Values less than 150mcg/L are considered iodine insufficient. (2) Based off of NHANES data from 2003 to 2014, a significant portion of pregnant women in the United States were iodine insufficient. (3) Women who consumed little to no dairy products were the highest at risk for iodine insufficiency based on their urinary iodine.
How much iodine is in my food?
Focusing on adding a variety of foods to your diet is always the most important point. The richest form of iodine is cod which has 146mcg in 3 ounces. An 8 ounce glass of milk provides 84mcg of iodine. Iodized table salt will provide 78mcg in . teaspoon. One of the most potent sources is dried seaweed which provide 116mcg of iodine in just 5 grams or 2 tablespoons. (4)
Am I getting enough iodine?
Women who do not use iodized salt and/or follow vegan diets may not be getting enough iodine in their diet. Women who eat moderate amounts of iodine but also eat many goitrogens which include soy and cruciferous vegetables. Goitrogens are substances that interfere with the way our bodies will absorb iodine.
What should I focus on for Iodine?
Adding iodine rich foods to your diet is important to support your thyroid health. Focus on adding a variety of whole foods into your diet. This would include iodized salt, dairy products, and low mercury seafood such as haddock, pollock, cod and catfish. If you are pregnant and breastfeeding check to see if your prenatal or postnatal vitamin has iodine in it.