Iodine is an essential trace mineral that doesn’t get the press or attention that other vitamins and minerals do. However, iodine deficiency is on the rise, due to restricted eating patterns such as very low-carb diets, food elimination such as no dairy, diets that do not include seafood or fish, and food trends such as plant-based diets without appropriate inclusion of foods that contain iodine.
Iodine is needed to make the thyroid hormones thyoxine (T4) and triodthyronine (T3). Thyroid hormones play a key role in the regulation of various processes in the body including protein synthesis, metabolism and enzyme functions.
For women who are pregnant and breastfeeding, iodine is critically important for the baby’s bone and brain development. Iodine deficiency is the most preventable cause of intellectual disability in infants. Studies indicate that prenatal iodine deficiency may result in irreversible neurocognitive defects and lower childhood IQ.
What Foods Contain Iodine?
Iodine is in the soil and also in the ocean, so animals that graze on grass and seafood contain iodine. These foods include milk and grains grown in iodine-containing soil, as well as seaweed (kelp, nori, kombu and wakame) from the ocean.
How Much Iodine Do I Need?
|Age||Recommended Amount of Iodine Per Day|
|0-6 months||110 mcg|
|Infants 7-12 months||130 mcg|
|Children 1-8 yrs||90 mcg|
|Children 9-13 yrs||120 mcg|
|Teens 14-18 yrs||150 mcg|
|Pregnant teens and women||220 mcg|
|Breastfeeding teens/women||290 mcg|
Source: National Institutes of Health, Office of Dietary Supplements. Iodine fact sheet for health professionals.
Who Is at Risk of Iodine Deficiency?
Iodine deficiency does require a medical diagnosis. Symptoms can include goiter, a bulge in the neck caused by the enlargement of the thyroid gland, fatigue, constipation, difficulty in thinking and comprehension, sensitivity to cold and delayed growth and cognition development in children.
Plant-based foods have lower iodine content than animal-sourced foods. Those who don’t eat dairy foods also consume less iodine. Plant-based milks are not good sources of iodine.
Vegans may be at higher risk of low iodine levels. Be aware that the majority of canned and boxed as well as frozen foods are prepared with non-iodized salt. Salts such as sea salt, Kosher salt, Himalayan salt and sal de fleur don’t contain iodine. Look at the label before you buy. There are a few brands of iodized sea salt, but not many.
Those who eat copious amounts of cabbage family vegetables such as kale, Brussels sprouts and collards can may not be aware that these foods contain substances called goitrogens that can interfere with the thyroid’s ability to absorb iodine.
For those who have adequate iodine intake, this would not be a problem, but high levels of these vegetables along with low iodine intake may be a concern. The message is not to eliminate cabbage family vegetables, but to make sure you include a variety of vegetables, as well as other foods that contain iodine.
If you’re vegan or don’t consume dairy foods or add salt to food, it may be worthwhile to consider a multivitamin-mineral supplement that contains iodine (check the label).
How Much Iodine Is in Food?
|Cod, baked, 3 oz||158|
|Plain, fat-free Greek yogurt, 6 oz||87|
|1% dairy milk, 1 cup||87|
|Iodized salt, ¼ tsp||76|
|Fish sticks (3)||58|
|Almond milk, 1 cup||2|
Source: NIH, Office of Dietary Supplements. Iodine fact sheet for health professionals.
How Can I Increase My Iodine Intake?
— Start with using an iodized salt ( check the label) and add a little salt to your sauces, soups and vegetables.
— Eat fish and shellfish more often (fresh, frozen or canned).
— Seaweed can be crumbled and added to a salad or even to a sauce to add an umami taste.
— Yogurt is a great add in to a bean-based soup or a squash soup to add protein, as well as calcium and iodine.
— Oatmeal can be made with milk instead of water, and dairy can be a great foundation for smoothies.
Bottom Line on Iodine
Iodine is an essential — not optional component — of a healthy diet. Try to optimize intake every day.
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