It has become common knowledge that your thyroid needs sufficient iodine levels to function properly. This is absolutely true, and the long term effects of low iodine levels are commonly documented in countries where foods aren’t fortified with iodine. Patients who are iodine deficient may develop hypothyroidism or develop enlarged and inflamed thyroid glands, called goiters. If iodine deficiency can be so detrimental, why isn’t everyone supplementing? Let’s unpack the connection and our point of view here at MIMC.

What is the role of iodine in thyroid function?

Iodine is a critical backbone of T4 and T3 which are the hormones that your thyroid gland produces and your body needs to power your cells. T4 is a prohormone – created from tyrosine plus 4 iodines all linked together. 

As your tissues demand it, the prohormone may also go through a step called deiodination. This is a fancy word for the process of plucking off one iodine from T4 to form the thyroid’s most metabolically active form of hormone—triiodothyronine (a.k.a. T3). That’s mouthful, I know. 

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However, if iodine is critical for thyroid function, why aren’t we recommending iodine supplementation for every patient exhibiting low thyroid symptoms?

First, iodine deficiency is not common in the United states. Our foods are generally fortified with iodine (common: iodized salt) and if you eat the top foods on this list, you’ll most likely hit the 150 mcg of iodine recommended in a day. Actually, most multivitamins, prenatals or other multiminerals also have around 150 mcg of iodine in them and will be cherry on top of your daily dietary intake. 

You can test your iodine levels via urine or blood – although if you’re really worried about levels, urine testing will be the most accurate. 

Risk of over supplementing with iodine 

There are a couple concerns when it comes to (over) supplementing with iodine. That includes a potential increased risk of autoimmune thyroiditis (Hashimoto’s thyroiditis) and a reflexive slow down in T4 output, causing TSH to rise (hypothyroidism). Which, of course, is the clear opposite of what we’d like to happen with our precious thyroid.

With so many good things out there to help with thyroid function and potential controversies surrounding over supplementing with iodine and thyroid damage that can happen – my thoughts have always been “why risk it?” If we don’t know who it will help or hurt, why risk a potential increase in autoimmune risk, or reflexive hypothyroidism with iodine supplementation? 

On the flip side, it may not be iodine deficiency causing thyroid issues at all. Things like exposures to toxic chemicals can cause iodine to be displaced from the thyroid gland and cause a functional hypothyroidism. Or deficiencies in other essential thyroid nutrients such as selenium and zinc.  

RELATED: 3 Common Chemicals That Could Impact Your Thyroid

Bottom line, we are here to unpack the topic in a way that is customized to you because throwing something at a “problem” can be a risky route when you don’t understand the root cause.

Dr. Cassie Wilder

Dr. Cassie Wilder is a registered Naturopathic Medical Doctor (NMD) and founder of MIMC. Her passion is empowering her patients through education, understanding, and support through their healing journey. After graduating from Iowa State University with a Bachelors of Science in Kinesiology and Health, Dr. Wilder earned her Doctorate of Naturopathic Medicine from Southwest College of Naturopathic Medicine & Health Sciences, a fully accredited and nationally recognized institution in Phoenix, AZ. During her clinical training, she received extensive hands-on training with many leading experts in the field of functional medicine and developed a passion for treating hormonal imbalances, thyroid disorders, cardiovascular concerns, and adrenal fatigue.