Iodine is an essential trace mineral needed for optimal thyroid function. It is required to make thyroid hormones, T3 and T4, which regulate growth, neurological development, metabolism, and digestive function. Insufficient iodine intake can lead to a condition called hypothyroidism, as well as weight gain, poor cognition, and constipation. Iodine also plays a role in estrogen metabolism, and has been found to have protective effects against breast cancer. It may also reduce cyst formation and breast tenderness.
Unfortunately, mild iodine deficiency is common among women and individuals with dietary restrictions. Data from the 2007-2010 U.S. National Health and Nutrition Examination Survey indicates that 37% of women during childbearing years have insufficient iodine intake. The World Health Organization estimates that over 30% of the world’s population is iodine deficient.
Iodine is typically found in soil and seawater, and in animals who are fed iodine-containing foods. However, there are many regions of the U.S. that have poor iodine content, including the Pacific Northwest. As a result, produce grown in the PNW, as well as grazing animals and their milks, have lower iodine content than those grown elsewhere in the nation.
Iodized salt is meant to address this concern. However, iodine is very unstable and diminishes over time, with losses of 10-100% over the span of a year depending on the packaging, temperature, and humidity of the stored salt. Therefore, iodized salt is not the most reliable source of iodine. Another problem is processed food, which often does not contain iodized salt.
Dietary restrictions can further contribute to poor iodine intake. Foods rich in iodine include seafood, seaweed, as well as meat and dairy products from animals grazed on iodine rich soils. Vegans and vegetarians — as well as anyone avoiding dairy, seafood, or seaweed — are therefore at an increased risk of iodine deficiency. Moreover, cruciferous vegetables and soy can interfere with iodine. High intakes of these foods, along with a diet low in iodine, can exacerbate insufficiency.
Iodine needs fluctuate throughout the human lifecycle, and most adults need 150mcg per day. However, needs greatly increase for pregnant or nursing mothers, who require 220-290mcg of iodine per day. This is of great concern because the fetus and infant are entirely reliant on their mother’s intake to produce thyroid hormones. Inadequate iodine intake can lead to neurological problems and lower intelligence in children. However, too much iodine can lead to iodine induced hyperthyroidism. It is important to work with your dietitian for individual guidance.
Here are some great ways for Pacific Northwesterners to increase iodine intake:
- Use Redmond’s Real Sea Salt for a natural source of iodine.
- Snack on organic seaweed snacks.
- Make a wrap with a nori sheet.
- Sprinkle dulse granules on meals for a smoky flavor.
- Enjoy quality wild caught seafood 2-3x per week.
- Add a kelp frond to soup stocks or bone broth while cooking.
- Enjoy a poke bowl that includes seaweed and quality seafood.
- If using iodized sea salt, buy a new container every season, for optimal freshness.
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