Just 15 Minutes of Sunshine Will Boost Your Immunity

Everything you need to know about the healing power of the sun, its potential role in treating COVID-19, and how it can resolve the other pandemic, Vitamin D Deficiency

Jen McGahan
Sep 4, 2020 · 10 min read
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Photo by John Fornander on Unsplash

One sunny day, my mother rolled the TV outside and shooed us out. This was the 70s and screentime wasn’t a concern. My sister and I could watch reruns all day long, for all she cared.

This was about the sunshine we weren’t getting.

Her mantra, every time she spotted one of us kids lying around reading, doing crosswords, or rug-hooking (typical summer vacation activities), was “Go get some sunshine.” Before all the studies that showed how beneficial sunlight is, she intuitively knew, like ancient cultures in history, that it would make us happier, healthier people. Of course, she may have wanted the house to herself for five minutes.

Today, as a writer and parent of two screen addicts, I know a certain amount of sunshine every day does wonders for your health and spirits. On the days when I go outside and soak in some rays, I feel happier and sleep better.

So what is it about sunshine? What’s the science behind the benefits of human exposure to sunshine? Is there a reason why ancient Egyptians worshiped the sun and Victorian doctors prescribed beach vacations to their tuberculosis patients?

While the world is stewing in the turmoil of the most recent pandemic, COVID-19, another pandemic quietly and continually does damage to public health. An estimated billion people worldwide, across all ethnicities and age groups, have Vitamin D Deficiency (VDD), responsible for over 30 cancers and many common health conditions.

The answer? Sunshine.

[An aside: I am no doctor, but I enjoy researching health topics, the benefits of nature, and the body’s natural ability to heal. I’ve been curious about the benefits of sunshine, so I decided to go digging. Current research related to sunshine, vitamin D production, and the current COVID-19 pandemic shed light (pun intended) on oodles of interesting facts.]

When sunshine hits the skin

Amazing things happen when the skin absorbs the sun’s direct rays. These benefits of sunshine only occur when the skin is exposed without sunscreen, so be aware of this before you head out. Sunscreen with an SPF of 30, applied to the skin before sun exposure, cuts 95% of the harmful — and helpful — UVB rays. The advice to get direct, unfiltered sunlight on the skin can be a contentious issue among dermatologists and sunscreen product makers, who assert that the risk of melanoma increases due to UVB rays.

Many other scientists and doctors contend that the benefits of direct sunshine on the skin far outweigh the risk of skin cancer. The main thing is not to burn. It’s a sunburn, not the exposure to UVB rays, per se, that cause skin cancer. Get a bit of sun on your skin before you start turning red (this is critical)… and then seek shade, go inside, or apply the chemicals.

UV light is the source of beneficial Vitamin D, but it is also responsible for certain melanomas caused by sunburns, so take proper precautions. For optimal health, get regular amounts of sunshine; just don’t get a sunburn. Short amounts of sunshine over as much of your body as possible, every day, will significantly improve your life. Here’s why.

Infection-fighting T cells get moving

Separate from the production of Vitamin D and its impact on immunity, sunshine on the skin triggers a specific response in the body. Scientist found that low levels of blue light found in sunlight makes T cells move faster. The synthesis of hydrogen peroxide in T cells energizes them to move toward damaged cells in the body.

The research by Georgetown University Medical Center also decoded the molecular pathway activated by sunlight, and it’s subsequent protection against infection and inflammation. [More on the infection-fighting properties of Vitamin D, later.]

Blood pressure drops

Sunshine benefits the whole circulatory system. A 2014 study published in the Journal of Investigative Dermatology found that sunshine on the skin alters levels of nitric oxide, a messenger molecule that affects blood vessel tone and lowers blood pressure. The upside is the decreased risk of heart attack and stroke for those who spend regular amounts of time in the sun.

Martin Freelisch, one of the cowriters of the study, says, “Avoiding excess sunlight exposure is critical to prevent skin cancer, but not being exposed to it at all, out of fear or as a result of a certain lifestyle, could increase the risk of cardiovascular disease.

Seratonin and endorphin levels rise

Want a happy, natural high? Face the sun. When sunlight hits the eye (not the skin this time), you instantly get a natural emotional boost due to an increase in the neurotransmitter serotonin. An Australian study showed that serotonin levels in blood taken from men on a bright, sunshiny day measured eight times more than those taken on a cloudy day. The mood-lifting hormone triggers increases in endorphins, too.

Melatonin decreases

To start your day feeling alert and focused, and keep it going through the afternoon, take a short walk around the block in the morning. Melatonin is the hormone that causes drowsiness and gives the body the signal that it’s time for sleep, so if you want to shake it off, nothing stops melatonin production in its tracks like a quick bask in the sunshine.

Humans thrive on a circadian cycle, which is why the body responds to daylight with a drop in melatonin. The brain’s pineal gland stops producing it during daylight hours until darkness causes it to surge again, and we get drowsy. People naturally follow the circadian rhythm; when the sun goes down, the body thinks it’s time for bed.

The biggie: the production of vitamin D

Sunshine-produced vitamin D is the most significant benefit in the body, at least it’s the one you hear most about.

It only takes 20 — 40 minutes for a fair person to make all the vitamin D the body can produce in the day; that’s about several thousand units! It takes two to three times longer for darker-skinned people. Yet, most people don’t get near enough sunshine, due to lifestyle, career, religious practices of wearing long body-covering garments, or due to simply having darker skin.

Furthermore, certain populations simply don’t process Vitamin D from sunshine as well as others: breastfed infants, older adults, people with Crohn’s or Celiac disease, and obese people. Reasons vary but they include lower efficiencies in the liver, the skin, and body fat absorption.

Ideally, people should get 80% of the body’s Vitamin D from the sun, the other 20% must come from the diet. Unfortunately, there aren’t too many foods of which a single serving comes close to satisfying that requirement. The NIH’s recommended dietary allowances for vitamin D1 is 600 IU (International Units). A serving of trout or salmon are two foods that come close at around 500 IU; a half cup of mushrooms exposed to UV sunlight contains about 360 IU. A tablespoon of cod liver oil has 1360, which is why it’s said to be so good for you.

Yet, some endocrinologists are recommending much higher doses of Vitamin D to prevent VDD. In a paper titled “The Big Vitamin D Mistake,” Dimitrios T. Papadimitriou ups the daily recommendation to 4000 IU/day for people over 8 years old. Without adequate sunlight on the skin, many people may require supplementation.

What’s so great about vitamin D?

Vitamin D, produced in the skin after sun exposure, is vital to a healthy body.

  • It builds and maintains bone tissue.
  • It aids in memory.
  • It alleviates rheumatoid arthritis, asthma in children, metabolic syndrome, and type 2 diabetes.
  • It prevents certain types of cancer.
  • It aids immunity to viruses.
  • It helps babies and children grow.
  • It provides therapy for skin conditions.

Vitamin D is most known for its ability to help the absorption of calcium and phosphorous, which are crucial to building and maintaining healthy bones. This is important because bones grow during the first 2 decades of a lifetime; after about age 20, it’s all about maintenance.

Bones are made of hard, honeycomb-like tissue with many holes inside. They are constantly remodeling themselves with two types of cells. Osteoclasts are cells that break down bones, leaving larger cavities in the bone tissue and making it more delicate and breakable. Osteoblasts, on the other hand, are cells responsible for creating new bone tissue. This remodeling is a lifelong process.

The relationship between vitamin D and calcium

Bones are the main storage sites for calcium in the body, but your blood needs it too. Calcium is necessary for heart health, blood clotting, and muscle function. The bones have the job of both supporting a body’s structure and load-bearing capacities, while also providing the body’s systems with calcium and phosphorous. Bones are always having to regulate these two functions to keep them in balance.

This is why Vitamin D is so necessary. When vitamin D is absorbed through the skin via sunshine, the blood can then absorb calcium very easily. This is a good thing because if there’s not enough calcium in the blood, calcium is “stolen” from the bones.

Low calcium in the blood triggers the parathyroid hormone (PTH) to activate osteoclasts, to start “chipping away” at the bone tissue faster than osteoblasts (the builders) can fill in. Sunshine ultimately helps maintain bone density because it keeps the bloodstream content with the necessary levels of calcium. In fact, studies show that women who worship the sun have only one-eleventh the risk of hip fractures as women who avoid it.

Bone related diseases like rickets and osteoporosis are also alleviated by exposure to sunshine and the manufacturing of vitamin D.

Vitamin D may improve memory

Nerve cell growth in the hippocampus is a subject of a paper that rocked the brain health world last year. Not long ago, it was believed that the brain’s neural growth stopped after toddlerhood, but now scientists are not so sure. Alzheimer’s disease is associated with a decrease in vitamin D receptors in the hippocampus. Since the hippocampus is responsible for the memory of names, dates, and events, as well as spacial memory (directions, locations, and orientation); maintaining nerve cell growth could help to halt this disorienting condition. Some studies prove that there may be a link between Vitamin D and nerve cell growth in the hippocampus.

The problem of vitamin D deficiency

Increased interest in Vitamin D as the new “miracle vitamin” has inspired countless studies and theories into advocacy. Among the many claims that have been studied and supported, many of them involve common widespread diseases. Deficiency in vitamin D is linked to many diseases. Increasing its levels through supplementation of good old fashioned sunshine is one of the cures.

In recent studies, vitamin D insufficiency was associated with current asthma and wheeze in children as well as current asthma in adults.

Studies show that normal blood serum levels of Vitamin D reduced the risk of developing type 2 diabetes by up to 55%, indicating that healthy doses of daily Vitamin D may help manage insulin levels.

Vitamin D deficiency has been linked to metabolic syndrome and its variations, which put people at risk for cardiovascular disease, stroke, and diseases related to fatty buildup in artery walls. Many studies suggest that an increase in vitamin D could reduce the risk of some of these diseases.

Vitamin D‘s positive effects

The Vitamin D hormone helps promote cellular self-repair and is linked to decreased risk and reduction of several different kinds of cancer, including cancers of the colon, breast, and prostate cancers. Not all cancers benefit from the hormone’s positive effect on cells, however. According to the NIH, higher rates of Vitamin D in the blood have been linked to higher rates of pancreatic cancer.

There’s a close, relationship between Vitamin D and the GH (growth hormone), though it’s yet not well understood. The relation to bone and muscle health is commonly known, but Vitamin D correlates with an increase in GH as well. In many parts of the world, parents bring their babies into the morning sunshine to boost growth.

Why Vitamin D is critical for immunity

Why do some people always get colds and flu, while others seem to remain healthy every year… even without a flu shot? Some say it could be related to higher levels of vitamin D in their bodies. Microbiologist Adrian Gombart asserts that adequate levels of vitamin D “may alleviate many of the chronic ills that befall us as we age.”

People deficient in vitamin D report more cold and flu infections than others with higher levels of vitamin D in the blood. And vitamin D may aid the body in fighting off these diseases in the first place.

Innate immunity is the body’s job in keeping infection-causing microorganisms out of a healthy body. Adaptive immunity, or acquired immunity, is that which takes over after exposure to a virus or disease-causing bacteria. Vitamin D is a receptor for the antimicrobial peptide gene, which helps the body fight infection in the body, particularly in the lungs, where seasonal infections take root.

In 2017, a global study authored by Harvard Medical School emergency medicine doctor Carlos Camargo showed that daily supplementation of vitamin D helps the body fight infection, and cuts the risk of acute respiratory infections in half. Even before COVID-19, he asserted that respiratory infections were responsible for millions of emergency department visits and millions of deaths globally each year.

Vitamin D a possible aid in treating COVID-19?

Now that scientists know more about vitamin D’s ability to help the body fight off viruses like the cold and flu, the results of recent research propose that vitamin D’s suspected anti-viral mechanism could also provide innate immunity against COVID-19. In combatting this pandemic, some doctors are already recommending an increase of Vitamin D and melatonin as potential adjunct treatments.

Other benefits of sunshine

Finally, some health benefits don’t seem to have a basis in Vitamin D, but they are still worth noting.

A 14-year study of nurses’ health showed that environmental factors like sunshine exposure were linked to incidences of Rheumatoid Arthritis. Furthermore, the earlier in life the participants lived farther north, the more likely the incidence of the disease.

In a dermatologist’s office, controlled doses of UV light are used to treat non-life-threatening skin conditions. A dose of sunshine naturally alleviates those same conditions. Acne, eczema, and psoriasis are all shown to benefit from the sun’s rays directly on the skin.

If I’ve missed something, or if you are a doctor, and you’d like to correct something in this article, please feel free to comment or reach out to me directly.

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Jen McGahan

Written by

Curious mom, writer, & lymphatic massage therapist. I teach a persuasive writing course, too. Start here: https://www.jenmcgahan.com/power-words

Portals Pub

Fearless learning, disparate connections, and honest writing

Jen McGahan

Written by

Curious mom, writer, & lymphatic massage therapist. I teach a persuasive writing course, too. Start here: https://www.jenmcgahan.com/power-words

Portals Pub

Fearless learning, disparate connections, and honest writing

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