Doctor’s Heart Series Chapter 8: Sunlight and Vitamin D
Importance of Sunlight and Vitamin D in our daily lives !
Sun Temple, Konark
Our flight reached Bhubaneshwar, which lies in the eastern part of India, it was early morning, and the sun was in full glow. Surprisingly, the city was immaculate and well-maintained compared to many cities in India. Bhubaneshwar city was a less-known, more beautiful, and clean city than I had expected. I discovered the fantastic temples and their architecture from early BC to now. Once called Kalinga, it was famous for its incredible Craftmanship and Artistry. During the reign of Ashoka, the King of the larger Mauryan Empire around 300 BC, wanted to conquer the Kalinga kingdom for expansion. Ashoka Vs. The Kalinga war, one of India's most famous and bloodiest wars, supposedly took hundreds of thousands of lives on both sides. After the war, King Ashoka adopted the path of peace and tranquility and resorted to Buddhism. The Ashoka chakra, or the wheel, became the symbol of the current Indian flag. Temples in and around the city are primarily dedicated to Lord Shiva. The Architecture was Great; some temples were rock solid, standing tall even after the millennium.
We reached Konark Sun Temple, an architectural marvel and World UNESCO Monument. The Konark Sun Temple was an hour from Bhubaneshwar. The Konark Sun Temple was built in 1250 AD during the reign of King Narasimha Deva-1 from stone in the form of a giant ornamented chariot dedicated to the Sun god, Surya. In Hindu Vedic Scriptures, Surya is represented as rising in the east and traveling rapidly across the sky in a chariot drawn by seven horses representing seven days a week. The visionary king built a massive temple dedicated to Sun God, standing 229 (equivalent to the Taj Mahal) feet tall, which fell to ruins in 1837. The audience hall, about 128 feet (39 m) tall, still stands and is the principal structure in the surviving ruins. Narasimha Deva I, fascination with the Sun God, and witnessed by the incredible architecture. Each wheel works as a Sundial, giving an accurate time to the minute. I got Sun temple in the discussion because I would like to shed some light on the benefits and risks of Sun exposure. So let’s get into it.
A brief history of the Sun…
Sun and Earth optimized life to flourish. But how did all this come about? There is no life without Sun on Earth. So how does the Sunlight benefit life forms? What exactly happens? For that, we have to dig deeper into plausible scientific explanations. Sun makes everything so easy for life to flourish. It drives weather, ocean currents, seasons, and climate, makes plant life possible through photosynthesis, and makes Vitamin D.
The Sun is the star at the center of the Solar System. It is a perfect ball of hot plasma heated by nuclear reactions in its core, radiating energy. Before we know all its benefits to life, we need to understand what happens inside the 4.8 billion years of nonstop self-immolation. To think of this, it's strange to think about all the life forms witnessed by the mighty Sun. But the burning of the Sun is not chemical combustion; it is a nuclear fusion. The Sun is considered the giant hydrogen bomb. Nuclear fusion occurs when one proton smashes into another proton so hard that they stick together and release some crazy energy. Are you with me!
Sunlight at the top of Earth's atmosphere is composed (by total energy) of about 50% infrared light, 40% visible light, and 10% ultraviolet light.
Ultraviolet Rays (UV light)…
Since the big bang, natural elements have taken place on this planet for life to sprout. As a result, numerous changes happened to the Earth. Sun is the cornerstone for planetary development and is essential for life forms. The Ultraviolet light from Sun mainly consists of UVA, UVB, and UVC. As depicted in the picture below, most of the UVC doesn't reach the surface of the Earth. Ultraviolet radiation reaches the Earth's surface, more than 95% of UVA, with the small remainder UVB. The fraction of UVB that remains in UV radiation after passing through the atmosphere heavily depends on cloud cover and atmospheric conditions. UV Light is strongly reduced by Earth's Ozone layer, so the amount of UV varies greatly with latitude and has been partially responsible for many biological adaptations, including variations in human skin color in different regions of the Earth. UVB light from Sun has physical effects, such as the production of Vitamin D, and can cause Skin cancer on prolonged exposure. UVB also significantly affects plant development, affecting most plant hormones and photosynthesis.
Vitamin D…
Vitamin D is the vitamin that is mainly produced from the Sun and some from consumption thru diet. During exposure to sunlight, 7-dehydrocholesterol in the skin absorbs UVB radiation and is converted to Pre-vitamin D3, which in turn converts into Vitamin D3. Pre-vitamin D3 and Vitamin D3 are converted into photo products, some of which have unique biologic properties. Sun-induced vitamin D synthesis is greatly influenced by season, time of day, latitude, altitude, air pollution, skin pigmentation, sunscreen use, passing through glass and plastic, and aging. Vitamin D is metabolized sequentially in the liver and kidneys into 25-hydroxyvitamin D, a primary circulating form (Lab test for vitamin D), and 1, 25-dihydroxy vitamin D, which is the biologically active form, respectively. 1, 25-dihydroxy vitamin D is essential in regulating calcium and phosphate metabolism to maintain metabolic functions and skeletal health. In addition, most cells and organs in the body have a vitamin D receptor. As a result, 1,25-dihydroxy vitamin D influences many biologic pathways, explaining association studies relating vitamin D deficiency and increased risk for many chronic diseases, including Cancer, Diabetes, Obesity, Osteoporosis, Depression, Cognitive impairment, Autoimmune conditions, and more. However, the direct link of causation of the Vitamin D is debatable.
Vitamin D, or most hormones, works as a Lock and key mechanism. Cells make the receptors which are the Locks. Just like Insulin, Vitamin D has to attach to the Vitamin D receptor to allow the action of the cell. Based on what we already know, it is easy to understand why the intestines, parathyroids, and bones make Vitamin D Receptors. These organs are all involved in regulating calcium levels, and we know Vitamin D regulates calcium metabolism. Now the data also suggests these receptors are everywhere, regulating the function of most organs, including the Kidneys, Lungs, Uterus, and Blood cells involved in immune function. However, their action on other organs has yet to be entirely defined.
Vitamin D deficiency ensues when there is a lack of Vitamin D from the Sun or diet. Most people living in the polar extremes usually get Vitamin D thru diet by eating Animal fat which is rich in Vitamin D. The regions closer to the Equator have better exposure to the Sun to direct Vitamin D throughout the year.
Vitamin D and COVID19…
It found that people with a vitamin D deficiency are more likely to develop a severe or critical case of COVID-19 compared to those with sufficient vitamin levels in their blood. For example, patients with a vitamin D deficiency were 14 times more likely to have a severe or critical case of COVID-19. Additionally, the mortality rate for those with insufficient vitamin D levels was 25.6%, compared with 2.3% among those with adequate levels.
Sunlight and Skin Cancer…
Skin Cancer is the most significant risk from sun exposure; The more extended the Exposure, the higher the risk. Skin cancer kills surprisingly few people: less than 3 per 100,000 in the U.S. annually. For every person who dies of skin cancer, more than 100 die from cardiovascular diseases. Sensible Exposure to the skin needs to be noted.
Sunlight and Hypertension…
Richard B Weller et al. researched nitric oxide, a molecule produced in the body that dilates blood vessels and lowers blood pressure. He discovered a previously unknown biological pathway by which the skin uses sunlight to make nitric oxide. As the Sun provides enough activation of nitric oxide, which in turn dilates the vessels and decreases blood pressure. Hypertension causes heart disease, and strokes are the leading cause of premature death and illness worldwide.
“Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.” - Lindquist,
Sunlight and other benefits…
Sunlight triggers the release of several other essential compounds in the body: nitric oxide and serotonin. It reduces the risk of many cancers, improves circadian rhythms, reduces inflammation, and dampens autoimmune responses. It improves virtually every mental condition you can think of. Additionally, exposure to sunlight benefits metabolic function, including blood sugars, by improving Insulin Sensitivity.
“Ultraviolet radiation from the sun has beneficial and harmful effects on human health. A balance is required between excessive sun exposure, which increases the risk of skin cancer, and enough sun exposure to maintain adequate vitamin D levels. It should be noted that the benefits of sun exposure may extend beyond the production of vitamin D. Other possible beneficial effects of sun exposure… include reduction in blood pressure, suppression of autoimmune disease, and improvements in mood.” - Australia Cancer Society endorsed by Dermatological society.
Studies on Vitamin D…
There are numerous studies done to showcase if Vitamin D benefits in preventing any major diseases. The vital study1 taking 25,871 healthy adults over age 50, 1 of the largest trial looking at vitamin-D benefits in incidence of cancer or major cardiovascular event like stroke heart attack and death from cardiovascular causes. Patients were given 2000 units versus placebo for 5 years and found to have no benefit in the study. Zhang et al.2, Luke get vitamin-D supplementation and mortality. It was meta analysis included 53 clinical trials showed vitamin-D did not change all cause mortality however it did reduce cancer rate by 16%. Martineau AR et al. showed only modest benefit with vitamin-D and acute respiratory infections3. Pittas et al.4 studied vitamin-D in prevention of diabetes type 2. He found no benefit in prevention of diabetes on supplementation with vitamin-D Versus placebo. Study was done for 2 and half years. ViDA5(Vitamin D Assessment) Trial showed 100,000 IUs of Vitamin D monthly vs. placebo for three years, did not improve rate of cardiovascular disease, cancer, and non-vertebral fractures. Lindquist found women with active sunlight exposure habits experience a lower mortality rate than women who avoid sun exposure6.
Vitamin D (25 OH level) in the lab:
< 20 ng /ml - Severely deficient needs high doses and repeat monitoring
20-30 ng/ml - Moderately deficient needs daily / weekly doses until normally optimized
30 and above - normal levels
Above 100 - high levels
Sources of Vitamin D…
Vitamin D is produced by the skin or ingested as food or a supplement. Sensible sun exposure (usually 10 min between 11am to 3pm of exposure of the arms and legs or the hands, arms, and face, 2 or 3 times per week) is one of the common vitamins for most people. For people unable to get enough sunlight due to living in polar opposites or during winter months etc., American guidelines recommend 600 IU of the vitamin D daily recommended for most adults and 800 IU for ages>70 years. D3 vs. D2 is better; studies have shown that D3 is slightly better. Dosage form daily vs. weekly vs. monthly(daily and weekly doses are better tolerated, and levels are maintained adequately compared to monthly dosing in most studies). In addition, monitoring serum 25-hydroxyvitamin D concentrations yearly should help reveal vitamin D deficiencies. Attaching the App for Vitamin D gives details about obtaining vitamin D naturally exposure to the sun based on the longitude, latitude, and skin color.
Dminder App…
Enter dminder, an app for your iPhone/iPad that tracks the Vitamin D you get from the sun. The sun is by far the best source of Vitamin D, and dminder allows you to optimize levels based on your location, body type, and time of day, all while making sure you stay safe by warning you of any risk to your skin getting burned. All of these features are available for FREE. Gives the Accuracy and availability all over the globe. - Dminder App.
My Take on Vitamin D…
Sun is an excellent resource for our well-being, its the nature’s bounty. The more we tap into this hidden resource, the better for our bodies to heal and keep us in balance. Vitamin D is a known essential vitamin for bone and calcium metabolism. Still, recent advances shed light on how vitamin D affects various immunological pathways. Clinical studies have mixed results, some showing benefits and others with minimal to no effect. But to keep in perspective, sunlight has been an integral part of the evolution share with various plants and animals. Vitamin D is essential, and our skins have abundant technology producing vitamin D on sun exposure. If unable to maintain vitamin D thru sunlight, use supplements or fortified foods. Measuring vitamin D is paramount when taking the excess supplement vitamin D; the chance of vitamin D toxicity is remote but not uncommon.
Sun has gotten bad press due to the heavy sunscreen industry. Exposure to the sun has benefits and also the risk of skin cancer. The benefits far outweigh the risk, especially in darker skin individuals. Some countries are reversing the sun exposure protocol to sensible sun exposure. When the time is right, and the sun is abundant, just lay down and soak in the sun to improve your health. If it can enhance Cardiometabolic health, Cancer prevention, prevent autoimmune disease. Using sunglasses to cover your eyes during the mid-afternoon is a must as it can damage eyes from the UV Light.
Prevention is better than cure. Sun is natural, and we are with our current lifestyles and hooked on to the machines shunning away the most essential element. Thus next time when you are outside, let your skin kiss the sun and feel good. Again sensible exposure is all that is needed.
Beautiful jazz by Takuya.. Enjoy.
Suman Manchireddy MD FACP FHM, Internal Medicine, Leesburg, VA.
Email : Care@ReliantMD.com
Disclaimer: This is purely informational and educational purposes only, seek medical advise prior to starting any testing or treatment regimen. The data presented here is researched extensively and has been condensed for a broader audience.
Recent study on Vit D and prevention of dementia in the prospective trial published on March 1, 2023
https://alz-journals.onlinelibrary.wiley.com/doi/full/10.1002/dad2.12404
This is an informative article for me, as I am severely deficient in Vit D. Due to dark skin, I avoid sun exposure too. This article encourages me to soak in some sun and not rely entirely on supplements alone. Thank you for writing and sharing.