There is a close connection between vitamin D and thyroid function. One of the most effective, abundant, reliable, and natural sources of vitamin D is sunlight.

What's the Age Of Our Bodies?

Research shows that vitamin D benefits many areas of the body including our cells, muscles, and bone health. It also has a notable influence on our immune system and thyroid function.

In this article, we will unravel the significance of sunlight for our thyroid health and overall wellness.

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In this article:

  1. How Can Summer Be Beneficial?
  2. What Is Vitamin D Doing?
  3. What Is the Recommended Daily Vitamin D Intake?
  4. Who Are at Risk of Developing Vitamin D Deficiency?
  5. Vitamin D Deficiency and Autoimmune Thyroid Disorder
  6. Soaking Up Sun Is for Better Health
  7. Things to Avoid
  8. Other Sources of Vitamin D

Vitamin D and Thyroid: The Gift of Sunlight

How Can Summer Be Beneficial?

Summer doesn’t only mark the end of school with three blissful months of freedom, it also provides universal health benefits. During the summer months, we experience more daylight hours, which provide a greater opportunity to absorb vitamin D.

This powerful substance has such a significant impact on the body that it is frequently included in the family of co-hormones rather than just a vitamin.

What Is Vitamin D Doing?

young woman enjoy sunbathe

Vitamin D, like vitamins A, E, K, and the mineral calcium, is fat-soluble. The active form of vitamin D, calcitriol, has an impressive influence on multiple cellular functions.

Cellular regulation and production of important substances such as enzymes, hormones, and neurotransmitters are all reliant on proper vitamin D levels. Furthermore, vitamin D is also necessary for proper thyroid function.

This vitamin is used in the final metabolic process that allows your thyroid hormone to function within the cell. If there’s vitamin D insufficiency in the nucleus, the thyroid hormone is not able to interact with the cell, thereby causing dysfunction throughout the body.

The deficiency of vitamin D can cause a wide array of issues. Below are the possible symptoms and conditions we associate with vitamin D deficiency.

  • Allergies
  • Thyroid problems
  • Autoimmune diseases
  • High blood pressure
  • Adrenal fatigue

A meta-analysis published in the journal Nutrition also linked vitamin D deficiency to a higher risk of thyroid cancer and suggested vitamin D deficiency as a risk factor for developing thyroid cancer. It consisted of 14 articles and the researchers found that preoperative thyroid patients had lower serum 25-hydroxyvitamin D levels.

Additionally, there are also studies linking vitamin D deficiency to cardiovascular disease. This is surprising since the heart is a large muscle with vitamin D receptors like skeletal muscles.

The Health Professional Follow-Up Study checked 50,000 healthy men’s vitamin D blood levels and followed them for 10 years. Researchers discovered that men with low vitamin D levels were twice as likely to have a heart attack as men with enough vitamin D.

What Is the Recommended Daily Vitamin D Intake?

How much vitamin D is enough? The amount of vitamin D you need each day depends on your age.

According to the National Institutes of Health, the recommended amounts in international units (IU), are:

  • Pregnant and lactating women: 600 IU
  • Birth to 12 months old: 400 IU
  • Children (1-13 years old): 600 IU
  • Teens (14-18 years old): 600 IU
  • Adults (19-70 years old): 600 IU
  • Older adults (71 years old and beyond): 800 IU

Who Are at Risk of Developing Vitamin D Deficiency?

There are about one billion people with vitamin D deficiency and insufficiency worldwide. A 2011 study reported that 42% of adults in the U.S. are vitamin D deficient: 69% in Hispanics and 82% in African-American adults.

These groups of people below are more likely to have vitamin D deficiency.

Older Adults

Older adults have higher chances of developing vitamin D deficiency because:

  • Their skin cannot synthesize this vitamin as they age.
  • They are likely to spend more time inside their homes.
  • They don’t get enough from their diet.

People with Darker Skin Tones

People with darker skin tones have higher pigment melanin levels in the epidermal layer of their skin. This decreases the skin’s ability to produce vitamin D from sunlight.

People with Fat Malabsorption Problems

Vitamin D is fat-soluble. The body relies on the gut’s fat absorption capability to utilize this vitamin.

People with reduced ability to absorb fat may need to take vitamin D supplements. Celiac disease and Crohn’s disease may increase the intestines’ permeability leading to a condition called leaky gut.

Leaky Gut Definition: A condition of the digestive tract wherein the membrane increases its permeability allowing even the essential nutrients to pass through and not be absorbed

Obese People

Obesity does not alter the skin’s ability to synthesize vitamin D. However, higher amounts of subcutaneous fat isolate more of the vitamin and change its release into the bloodstream.

Other vitamin D deficiency risk factors are:

  • Not eating much dairy or fish
  • Frequent use of sunscreen when going out
  • Living in countries far from the equator where there is little sun
  • Staying indoors

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Vitamin D Deficiency and Autoimmune Thyroid Disorder

One of the most important bodily regions affected by vitamin D is the immune system.

If someone is experiencing vitamin D deficiency, they are at higher risk of developing harmful autoimmune thyroid diseases such as Hashimoto’s thyroiditis (also known as Hashimoto’s disease) and Graves’ disease. Severe or extended periods of vitamin D deficiency can result in an overactive thyroid and damage its system.

In the case of Hashimoto’s disease, one’s own immune system attacks the thyroid causing irreparable damage that reduces its efficiency and productive ability. This can result in thyroid disorders such as hypothyroidism (underactive thyroid), as well as a slowed metabolism and hormonal imbalances.

In addition, those who are experiencing common symptoms of hypothyroidism and vitamin D deficiency such as fatigue, depression, aching bones, and recent weight gain may benefit from having their vitamin D and thyroid-stimulating hormone or TSH levels tested.

According to recent studies, there’s a connection between Hashimoto’s disease and vitamin D.

In a Chinese study presented at the annual meeting of the American Thyroid Association in October of 2014, it was found that vitamin D deficiency is associated with increased thyroid peroxidase antibodies (also called TPO antibodies) in autoimmune thyroid patients.

This shows that insufficient vitamin D levels may be a significant contributor to thyroid autoimmunity conditions. Of the 66 patients who partook in the study (34 had Hashimoto’s disease and 32 had Grave’s disease), 82% had low levels of vitamin D.

The connection between Hashimoto’s thyroiditis and vitamin D deficiency was reinforced further by a 2011 study. The study in question focused solely on Hashimoto’s patients.

Of the 161 participants, 92% of them had a vitamin D deficiency. Although these numbers are staggering as well as frightening, they exemplify the importance of vitamin D regarding autoimmune function.

Soaking Up Sun Is for Better Health

Sunlight is the best and most natural source of vitamin D. Our skin’s exposure to sunlight specifically from ultraviolet B makes up 90% of vitamin D in our body.

Furthermore, medical practitioners frequently recommend that we spend 15 minutes to an hour out in the sun each day. We can do this through numerous outdoor activities such as walking, napping, or even reading articles on how to have a healthy thyroid.

Even if you have not been diagnosed with autoimmune thyroid disease or other thyroid conditions, it is greatly beneficial to understand why increased vitamin D intake and testing is being recommended by many medical practitioners. Here are some fun outdoor summer activities you can do to get sufficient vitamin D supplementation:

  • Fishing
  • Jogging
  • Camping
  • Hiking
  • Climbing
  • Canoeing or kayaking
  • Playing frisbee
  • Biking
  • Going to parks
  • Having a barbecue
  • Bird watching

Things to Avoid

Being aware of the impact of vitamin D deficiency on our bodies is helpful but it is not the primary goal. Avoiding deficiency and providing the body with adequate amounts of this powerful vitamin should be high on our list of summertime activities.

There are several situations, products, and activities we need to avoid to lower the risk of consuming our vitamin D reserves. The following list outlines some common contributors to vitamin D deficiency:

  • Sunscreen that inhibits vitamin D production and absorption
  • Washing off natural body oils needed for absorption prior to exposure to the sun
  • Wearing excess clothing or not exposing one’s skin to the sun
  • Poor weather due to location or time of year
  • Chronic stress
  • Environmental toxins such as pesticides and BPA’s
  • Working indoors for extended periods

Other Sources of Vitamin D

Alternatively, there are several ways to improve one’s vitamin D levels. Taking part in outdoor activities when the sun is shining bright can help improve one’s vitamin D absorption and intake.

However, not all sunlight is created equal. Sunlight is composed of both UVA and UVB rays.

UVB is beneficial in producing vitamin D whereas UVA can break down and destroy vitamin D. In addition to spending time outside, consuming the following foods can boost one’s levels:

  • Beef liver
  • Oysters
  • Eggs
  • Sardines
  • Butter
  • Sour cream
  • Mushrooms
  • Vitamin D supplements (chewable, capsules, drops, etc.)

After reading about the various effects and benefits of vitamin D, it is clear that maintaining an appropriate level is important. However, if one is reckless with supplementation, particularly if they have a thyroid condition, they risk further harm to their system.

Always consult a physician before beginning supplementation. Even though there is some risk in overindulging in vitamin D, that should not keep you from pursuing optimization.

Celebrate summer by spending some time outdoors to give your body the tools it needs to keep your thyroid and body healthy.

Do you know other effects and benefits of vitamin D to our thyroid? Share it with us in the comments below! 

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Editor’s Note: This post was originally published on July 13, 2017. and has been updated for quality and relevancy.