Feeling Sluggish? These 2 Nutrient Deficiencies May Be Affecting Your Thyroid

In 2018, 45-year-old Christine Street went to the ER with symptoms that resembled a heart attack — she had a headache, aches in her arm, unusual sweating, and a racing heart. She was fortunately wrong about her diagnosis, and the ER physician suspected that her symptoms were due to anxiety and stress. “I struggled to accept his diagnosis,” Street told FIRST. “But I was committed to following the ER doctor’s recommendation to manage stress, so I incorporated relaxation techniques like taking light walks, meditating, and trying to get adequate sleep every night.”

Those methods worked until a year later. “In 2019, I noticed my leg started to shake when I drove, my hand shook at times and I wasn’t sleeping a full night,” she said. Tired of her primary care physician telling her she was in great health, she visited a new doctor who sent her for blood work and recommended an endocrinologist. Street discovered that she had hyperthyroidism (when the thyroid makes too much thyroid hormone) and, possibly, was nearing Graves’ disease (an autoimmune disorder that causes hyperthyroidism). The possible cause? A diet low in vitamin D and selenium.

Though Street’s endocrinologist gave her two options — take a thyroid medication for the rest of her life or have her thyroid removed (and take thyroid hormones for the rest of her life) — Street chose to try a natural approach first. Her new primary care physician recommended 5,000 IU of vitamin D-3 daily for one month, then 2,000 IU of vitamin D-3 daily forever. Street also began taking 200 micrograms (mcg) of selenium five days a week, and one to two teaspoons of oregano daily (after reading that it reduces inflammation). Six months later, blood tests showed that her thyroid health had greatly improved, as did her symptoms of fatigue and brain fog.

Curious as to why the natural approach may have worked for Street? Continue reading below to learn more about vitamin D, selenium, and the thyroid.

Why Vitamin D and Selenium Deficiencies Affect the Thyroid

Research shows that there is a link between low vitamin D levels and autoimmune thyroid diseases (AITDs), such as Graves’ disease. While AITDs are also caused by a genetic pre-disposition, a lack of vitamin D may trigger certain thyroid conditions because it can negatively affect thyroid function. Indeed, a 2014 case study found that a woman in her 40s with untreated Graves’ disease and a vitamin D deficiency greatly benefited from a daily dose of D-3 for two years.

In addition, selenium is necessary for the normal function of the thyroid. Harvard Health reports that a selenium deficiency can lead to an AITD like Graves’ disease. It’s less clear whether supplementing with selenium can effectively reverse hyperthyroidism, but there’s good evidence that it can. A 2019 study published in Nature, for instance, states that patients with Graves’ disease who supplement with selenium may go into remission more quickly than patients who don’t. One scientific review from 2018, published in Hindawi, states that selenium supplements may improve thyroid function and make anti-thyroid drugs (which treat hyperthyroidism) more effective.

Symptoms of Vitamin D and Selenium Deficiencies

It’s not always easy to spot a vitamin deficiency, but these are the symptoms to monitor.

Vitamin D Deficiency Symptoms:

• Fragile bones (more prone to fractures)
• Muscle pain
• Bone pain
• Pins and needles in the hands and feet
• Muscle weakness in upper arms or thighs
• Muscle twitches, tremors, or spasms

Selenium Deficiency Symptoms:

• Headaches
• Nausea and vomiting
• Confusion, altered mental state
• Lethargy
• Seizures
• Coma (severe deficiency)

Supplementing With Selenium May Be More Important Than Ever

Shortfalls are a common cause of thyroid imbalances, says Ken Berry, MD, author of Lies My Doctor Told Me. “Selenium is absolutely necessary for healthy thyroid function — the active form of thyroid hormone can’t be produced in proper amounts unless selenium levels are adequate.” Indeed, in a study in The Journal of Clinical Endocrinology & Metabolism, people with low selenium were more likely to have low thyroid function. And since selenium is crucial for healthy immune function, deficits may trigger a misguided response that causes the immune system to attack the gland, leading to energy-draining imbalances.

Adding to the problem: Experts say that selenium deficiency is rare in the US. But modern farming may deplete selenium in soil and crops grown in it. And a study from PLOS One finds diets high in processed foods increase the risk of low selenium levels.

How To Fix Low Selenium Levels

If you suspect you have low selenium, ask your doctor to test your levels. Doctors can diagnose selenium deficits and the thyroid imbalances they trigger with blood tests. And while doctors often prescribe thyroid medication, the strategies below can also help.

1. Supplementing with selenium may optimize thyroid function. Sanul Corrielus, MD, CEO of Corrielus Cardiology in Philadelphia, advises taking 100 to 200 mcg. daily of a product that contains selenomethionine, an easily-absorbed form of the mineral. Note: Too much selenium can cause nausea, hair loss and other toxicity symptoms, so talk to your doctor before supplementing.
2. Also key: Eat selenium-rich foods. Dr. Berry advises options like beef, poultry, fish, and eggs daily. Tip: Two Brazil nuts boast up to 192 mcg. of selenium, so skip supplements on days you eat them to avoid selenium overload.

This content is not a substitute for professional medical advice or diagnosis. Always consult your physician before pursuing any treatment plan.

A version of this article originally appeared in our print magazine, First For Women.