Thyroid health

Selenium and thyroid health

by Marcelle Pick, OB/GYN NP

When it comes to supporting health through nutrition, there’s a powerful nutrient that seems to be one of nature’s best-kept secrets — selenium. It’s a mineral we all need in small amounts, but its effects can be huge! Selenium protects us against many health issues associated with aging, such as osteoarthritis and certain forms of cancer. But more than that — it’s crucial to the everyday function of our thyroid glands. That’s really what makes this nutrient important to women — because we’re much more prone to thyroid problems.

Selenium is easy to get excited about because it shows so clearly how our food choices impact how we feel — and our overall health. So let’s take a quick look at this often-overlooked nutrient.

What role does selenium play in thyroid health?

If we have low levels of selenium in our bodies, it’s harder both for the thyroid to make its hormones and for the body to convert thyroid hormones into the form that’s needed by our cells. That’s because selenium is a fundamental component of various seleno-proteins, molecules essential to the body’s ability to create and use thyroid hormones. Their role includes:

• Directly regulating thyroid hormone synthesis.
• Supporting the conversion of thyroxine (T4, the hormone produced in greatest quantities by the thyroid) to triiodothyronine (T3, the bioactive thyroid hormone that increases our cells’ basal metabolic rate).
• Protecting the thyroid’s tissues whenever the thyroid is affected by oxidative stress — something that happens all the time!

But selenium is not just critical to the production of thyroid hormones — it’s also a key regulator of thyroid hormone levels. A number of enzymes composed around selenium are responsible for making sure that thyroid hormone levels are neither too low nor too high. Some of these enzymes, called seleno-de-iodinases, maintain appropriate T3 levels in the liver, kidney, thyroid, and brain cells. Another enzyme, glutathione peroxidase, helps to limit T4 when its levels get too high.

Again, when there is too little selenium available for the body to make these enzymes, our bodies’ ability to maintain appropriate levels of the thyroid’s key hormones can suffer — and our overall health suffers too.

Selenium and iodine — natural thyroid partners

All of the problems that come with selenium deficiency are compounded by the fact that selenium works in tandem with another nutrient better known for its role in thyroid health: iodine. Simply put, selenium is responsible for the properly recycling of iodine in the body, so a person with too little selenium as well as too little iodine is much more likely to develop a significant thyroid imbalance.

One of the more serious forms of thyroid imbalance shows itself as an enlarged thyroid (goiter). Most people who develop a goiter have an iodine deficiency, but studies show that some may have a serious selenium deficiency, too. And when iodine deficiency goes hand-in-hand with selenium deficiency, it’s essential to treat both nutrient deficits to restore the thyroid to balance.

Where do we get selenium?

Most Americans get their selenium from food sources such as onions and garlic, vegetables in the Brassica (broccoli) family such as cabbage, cauliflower, and kale, which should always be cooked or steamed. Eggs, turkey, chicken, lamb, and various types of seafood also provide selenium. Selenium deficiency is more likely to occur in women who have problems with their digestive tracts or those who don’t eat a varied diet containing selenium-rich foods — which includes many women who eat the standard American diet.

How to make sure you get the right amount of selenium

One beautiful thing about selenium is that it’s so easy to get through food. Including selenium-rich foods like those listed above is your best first step in ensuring selenium intake adequate to support your thyroid.

But there is one drawback — the amount of selenium you can get in food isn’t always consistent, particularly if you have digestive issues. So if you aren’t able to regularly eat foods that provide dietary selenium, or if you have a digestive condition that impairs absorption, an alternative is to use a medical-grade multivitamin that includes selenium. (We don’t generally recommend single-element supplements because a carefully-formulated combination better ensures that selenium is correctly paired with appropriate levels of co-nutrients such as iodine.)

Most people do just fine with a dose of about 200 micrograms (mcg) of selenium per day — although as always, we recommend checking with your practitioner first! It’s especially important to have your practitioner continue monitoring your thyroid hormone levels if you’ve ever been diagnosed with any sort of thyroid disorder, such as Graves’ disease (hyperthyroidism), Hashimoto’s autoimmune thyroiditis, or any other form of hypothyroidism.

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Last Modified Date: 12/01/2011
Principal Author: Marcelle Pick, OB/GYN NP