Does Vitamin D Affect Your Thyroid?

Vitamin D Affect Your Thyroid?. I’m sure you’ve all heard, at least once in your life, how everyone is vitamin D deficient. Although that really is the case for the majority of people, it’s important to know all the roles vitamin D plays in our bodies and how vitamin D deficiency can affect our overall functions. 

My own journey took me on a path of researching every possible superfood and micronutrient that can help my thyroid heal and fight against cancer cells. This is how I discovered this important connection between vitamin D and the thyroid. 

Vitamin D 101

One of the most important micronutrients for our overall health and longevity, vitamin D is a fat-soluble vitamin that is naturally produced by the body when exposed to sunlight. It is also dominant in some specific foods and we can absorb it through eating them, but the levels are incomparable to sunlight. 

Vitamin D plays a myriad of important roles in the human body and that’s why vitamin D deficiency can be so detrimental. Other than sunlight and food, another important way of taking adequate amounts of vitamin D is through vitamin D supplementation. And even though the FDA recommendations do exist, they are often too low for the majority of people. 

They’re currently set at 600 IU (international units) for basically everyone. The only exception are infants under the age of 1 (400 IU) and older people over 70 years of age (800 IU). These often prove to be too low doses for even the healthiest adults, especially if living in countries that aren’t known for much sunlight throughout the year. 

Health Benefits of Vitamin D

Having optimal vitamin D levels in your blood ensures a myriad of health benefits, with plenty of research to support these claims. Here are some of the most important processes, health conditions, and diseases affected by vitamin D. 

• Bone health – vitamin D improves calcium and phosphorus absorption, reducing the risk of bone fractures as we get older. 
• Muscle strength – in those with vitamin D deficiency, studies showed an improvement in muscle strength after increasing their vitamin D levels. 
• Immune function and cardiovascular health – vitamin D regulates immune and inflammatory cells and helps control blood pressure. 
• Type 2 Diabetes – Vitamin D deficiency may have a negative effect on the biochemical pathways that lead to the development of type 2 diabetes.
• Multiple Sclerosis – studies link vitamin D deficiency with an increased risk for MS.
• Acute respiratory distress syndrome – due to COVID complications, many studies included vitamin D and its effect on the respiratory system. The results showed how vitamin D supplementation could lower the risk of infection from both, COVID and the flu, improving the immune function of the respiratory system.
• Mood and depression – low levels of vitamin D may negatively impact mood and worsen the symptoms of depression. On the other hand, vitamin D supplementation may have a positive effect, with research showing benefits for those suffering from major depressive disorders. 
• Weight management and weight loss – studies show a link between vitamin D supplementation and improved weight loss in obese patients. 

Vitamin D And The Thyroid

Vitamin D deficiency has been associated with autoimmune thyroid disease, such as Hashimoto’s thyroiditis. Even though there isn’t plenty of data to neither support nor debunk the theory, vitamin D supplementation may be beneficial to those suffering from this thyroid condition. 

Hashimoto’s thyroiditis is an autoimmune thyroid disease that involves chronic inflammation of the thyroid gland, leading to hypothyroidism or its impaired function. This means that over time, the thyroid gland starts producing fewer and fewer hormones, eventually leading to an underactive thyroid. Unfortunately, this is one of the thyroid diseases that can slowly develop over the course of several years before any kind of symptoms can even be noticed. 

Once shown, the symptoms may include fatigue, weight gain and water retention, constipation and diarrhea, increased sensitivity to cold, dry skin, depression and mood swings, muscle aches and reduced exercise tolerance, and irregular periods. All of these symptoms can be signs of many other diseases, and that’s why people don’t really think of their thyroid first. 

Further inflammation of the thyroid gland could lead to more severe diseases and even cancer. This is where finding out what helps improve your thyroid function really becomes crucial. 

As you can already tell, low vitamin D levels are linked to a high number of disorders and impaired functions in the human body. The involvement of vitamin D in thyroid diseases has been researched in the eighties and found similarities between the molecular structure of the vitamin D receptor and the receptor for thyroid hormone. This led to further research which showed how low vitamin D levels and certain vitamin D receptor (VDR) gene disorders may increase the risk of developing Hashimoto’s thyroiditis.  

Another autoimmune thyroid disease, Graves disease also shows vitamin D deficiency as one of the risk factors which may have an effect on its development. 

And lastly, low vitamin D levels and impaired signaling of the vitamin D receptor have been associated with the onset and progression of thyroid cancer. 

Vitamin D Deficiency

Vitamin D comes in two important forms: ergocalciferol – vitamin D2, and cholecalciferol – vitamin D3. Vitamin D2 is converted into D3 in the body, so when we’re measuring our vitamin D levels, we’re actually measuring vitamin D3 levels. 

The symptoms of vitamin D deficiency are very vague, and they include:

• Fatigue and increased tiredness
• Muscle aches and pains
• Severe bone or muscle pain or weakness
• Stress fractures, especially in your legs, pelvis, and hips

A very simple blood test can easily show whether your vitamin D levels are low or in range, followed by an X-ray scan of your bones, assessing your bone density. If diagnosed with a vitamin D deficiency, chances are you’ll be prescribed vitamin D supplements in a very high dose as even if you spent all day, every day under direct sunlight, your body wouldn’t be able to absorb adequate doses. 

Is Vitamin D Supplementation Necessary?

Unfortunately, there are several factors that may affect your ability to get adequate vitamin D from sunlight alone. Pollution and environmental toxins, spending plenty of time indoors, high-rise buildings that block sunlight, UV-protecting windows and sunscreen, as well as living in an area with fewer days of sunlight per year – these are all reasons why vitamin D supplementation may be your best option. 

Overdosing with vitamin D is extremely rare and involves very high doses of vitamin D supplements. Therefore, supplementing with recommended doses can only do you good in the long term. Still, before you decide to take a vitamin D supplement, consult with your physician and check your vitamin D levels. 

Final Thoughts

Vitamin D deficiency is a very common issue many people face today and studies show it can be one of the biggest risk factors for a variety of serious conditions, from impairing bone health and the immune system to the development of autoimmune diseases and more particularly, thyroid disorders. Since my thyroid cancer diagnosis, my doctor has recommended for me to take 10,000 iu daily.  I encourage you to check your vitamin D levels and do whatever is possible to bring them to their optimal range.