The Vitamin D Society of Canada has just released one of the best articles on the relationship of sun exposure and its potential for vitamin D production. Sun exposure is the natural way to obtain your essential vitamin D, and of course provides other essential photoproducts such as nitric oxide, serotonin, endorphin and BDNF.
Here is the press release from the Vitamin D Society, in full:
For Immediate Distribution
TORONTO, Ont (April 4, 2017) – The daylight hours are getting longer, the sun is getting stronger and summer is just around the corner. Make this the year that you optimize your vitamin D levels through effective sun exposure. Enjoy the health benefits and disease prevention from optimal vitamin D levels and learn to control your risks from sun exposure.
Vitamin D is made naturally in your body when UVB rays from the sun convert cholesterol in your skin to pre-vitamin D3. We make about 90% of our vitamin D from UVB sun exposure. UVB rays are short and only reach the earth when the sun is directly above us. We can’t make vitamin D in the winter in Canada because the sun is at too low of an angle and the UVB rays are absorbed in the atmosphere.
You make vitamin D in Canada between the months of May and October. The best time for exposure is around midday, between 10am and 2pm, when the UV index is above 3 and your shadow is shorter than your height. The further you get from noon, the lower the amount of vitamin D you’ll make. The sun’s visible light may penetrate through glass, but UVB light will not; therefore you will not make vitamin D.
Full body sun exposure at non-burning levels can create between
10,000-25,000 IU of vitamin D in your skin. You can never get too much vitamin D from the sun as your skin self regulates, whereas ingesting vitamin D does not have the same control. In addition, vitamin D that you make from the sun lasts twice as long in your body as vitamin D taken through supplements or food.
Statistics Canada reports that Canadian vitamin D levels have dropped by 10% over the past six years. The root cause of this decrease is lower sun exposure. People are just not getting outside around midday in the summer and making vitamin D, and when they are outside they are using sunscreen, which if applied correctly prevents 95%+ of vitamin D production.
In Canada, 12 million Canadians (35%) have vitamin D blood levels below the recommendations from Health Canada. This puts these people at a higher risk for several diseases, including cardiovascular disease, cancer, osteoporosis, diabetes, multiple sclerosis, Alzheimer’s disease and many more. In fact, a study completed in 2016 reported that if Canadians increased their vitamin D levels to the recommended level of 100 nmol/L, we would save $12.5B in healthcare costs and 23,000 premature deaths annually.
A recent study reported that women who avoided the sun have twice the risk of all cause death. The authors said that “avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.”
Skin cancer is a concern and risk of sun exposure must be managed and balanced with the benefits from vitamin D and other photoproducts. Research has shown that people with higher sun exposure such as outdoor workers, who have 3-10 times the sun exposure as indoor workers, have a lower incidence of melanoma. The National Cancer Institute reports that
melanoma risk is increased as a result of intermittent acute sun
exposure leading to sunburn. People who are a skin type 1, with white or very pale skin colour, red or blonde hair colour and who always burn and never tan, should severely limit their sun exposure.
The Vitamin D Society offers the following tips:
– Know your own skin and skin type. Don’t burn. Never overexpose yourself.
– Acclimatize or condition your skin for sun exposure by gradually
building or lengthening exposure times as your skin begins to tan to reduce your risk of burning
– Prevent burning and overexposure when required through the use of hats, clothing, shade and sunscreens.
– For vitamin D, get sun exposure at midday, between 10 am and 2 pm, when the UV index is above 3 and your shadow is shorter than your height.
– Expose more skin for a shorter period of time to generate more vitamin D while reducing your risk of overexposure.
It’s important to manage the risk and enjoy the rewards of moderate sun exposure for good health. Cancer Research UK, through the Consensus Vitamin D Position Statement, offers the following recommendation:
“Enjoying the sun safely, while taking care not to burn, can help provide the benefits of vitamin D without unduly raising the risk of skin cancer.”
“This advice may go against what current health organizations
recommend,” says Perry Holman, Executive Director of the Vitamin D Society. “They typically recommend you stay out of the sun at midday and use sunscreen when outdoors. But this would reduce your potential vitamin D production and does not consider the benefits as well as the risks of sun exposure on overall health. You need to have balance.”
About the Vitamin D Society:
The Vitamin D Society is a Canadian non-profit group organized to increase awareness of the many health conditions strongly linked to vitamin D deficiency; encourage people to be proactive in protecting their health and have their vitamin D levels tested annually; and help fund valuable vitamin D research. The Vitamin D Society recommends people achieve and maintain optimal 25(OH)D blood levels between 100 –
150 nmol/L (Can) or 40-60 ng/ml (USA).
To learn more about vitamin D, please visit www.vitamindsociety.org
For more information, please contact:
Melissa Andrade, Enterprise Canada 905-346-1230
THIS PRESS RELEASE CONTAINS MUCH OF WHAT YOU NEED TO KNOW ABOUT VITAMIN D, SUN EXPOSURE AND HEALTH. Please read it carefully, as it could save your life.
Babies who cry at night rather than sleep can wreak havoc on the health, wellbeing and work performance of their parents, so any natural method of helping the baby to sleep well would be welcomed in most families. One of the best natural methods is to expose the baby to outdoor light, and research showed that infants who slept well were exposed to significantly more early-afternoon light than their counterparts who did not sleep well. We have discussed previously in this blog that circadian rhythms are controlled to a great extent by sun or the lack thereof, and these researchers stated, “These data suggest that light in the normal domestic setting influences the development of the circadian system.” Proper circadian rhythms are also vitally important for adults, and when disrupted predict an increase in illness and death from many maladies, particularly from our number-one killer, cardiovascular disease.
Melatonin, which should exhibit high levels at night, is a sleep inducer, and its production is enhanced when the lights go out at night. But, for that to happen, there must be sufficient bright light earlier in the day.
For babies or adults, here is how the system should work: When we awake to sunshine, light enters the eye and stimulates serotonin production; we then quickly become awake and invigorated, and melatonin is suppressed. At day’s end, however, the bright light disappears (or at least that is how nature intended it), melatonin levels rise, and serotonin levels diminish. We begin to feel sleepy and ideally go to bed for a good night’s rest. It is a perfect system for our needs—that is until we stay up far beyond biologically natural hours by using artificial lighting.
Is there and answer to a disrupted circadian rhythm and poor sleep quality? Yes! A paper entitled Circadian clocks optimally adapt to sun for reliable synchronization has the answer. In it, the authors explain that circadian rhythms are best synchronized by sun. It therefore occurs that to escape the ravages of electric lighting, it would be a good idea to reset our biological clocks daily by being out in the morning sun and at other times, when possible, and to avoid long hours of light exposure at night. This could be one of the best therapies possible when we feel “out of synch.” And, catching some sun throughout the day would also keep serotonin levels higher and keep our moodiness in check. All of us know that we feel better when we are in the sun. This, coupled with enhancement of health, demonstrates that our friend, the sun, is an essential companion for optimal living.
So take care of your babies as nature intends, and also take care of yourself with non-burning daily sun exposure.
 Harrison Y. The relationship between daytime exposure to light and night-time sleep in 6-12-week-old infants. J Sleep Res. 2004 Dec;13(4):345-52.
 Jason Brainard, Merit Gobel, Benjamin Scott, Michael Koeppen and Tobias Eckle. Health implications of disrupted circadian rhythms and the potential for daylight as therapy. Anesthesiology. 2015 May ; 122(5): 1170–1175.
 Hasegawa Y, Arita M. Circadian clocks optimally adapt to sun for reliable synchronization. J R Soc Interface. 2013 Dec 18;11(92):20131018.
Benefits of sun exposure, by Marc Sorenson, EdD…
Interesting research regarding the critical necessity of sun exposure continues to mount.
There is no doubt that lack of sun exposure leads to disease, and a major factor in that scenario is a disrupted circadian rhythm. Researchers have stated that “Exposure to sunlight during the day, and darkness at night, optimally entrains biological rhythms to promote homeostasis and human health. Unfortunately, a major consequence of the modern lifestyle is increased exposure to sun-free environments during the day and artificial lighting at night.” Night-shift work is one of the worst contributors to the disruption of our natural biological rhythms, also known as circadian rhythms, and it certainly defines the sun-free environment discussed. There is a strong association of night-shift work to many diseases, but one of the most prevalent of these is breast cancer.
So what is natural and good for the health? Researchers have shown that a disrupted circadian rhythm can be reprogrammed, or “entrained” by exposure to a natural summer, meaning a cycle of 14 hours, 40 minutes of summer light, to 9 hours, 20 minutes of darkness. The authors state that this “light-dark cycle programs the human circadian clock to solar time, such that the internal biological night begins near sunset and ends near sunrise.”
Such a cycle would certainly seems natural for humans who were raised on ranches or farms where the day’s activities begins early in the morning sunlight and usually end near sunset. I know, because that pattern described my youth. For primitive peoples, that cycle was probably a necessity to gather the food necessary for survival. It is now ingrained in to our DNA, and disruption leads to disease.
So how are circadian rhythms reset to help our health? According to the aforementioned research (footnote 2), it can be accomplished by either a week of natural light exposure, or a weekend spent camping in nature. I am a camper, and I know that when the sun goes down, I am ready to sleep, and when the sun rises the next morning, I’m ready to start my day’s adventures.
The message here is that daytime should be spent outside in natural light. This will probably reduce the risk of many diseases, including breast cancer. It is also imperative that our skin receives its sun exposure to produce vitamin D and other healthful photoproducts. In addition being outside in the sun will increase our production of serotonin and enhance our moods.
Safely embrace the sun and save your life! Be sure not to burn.
 Ball L, Palesh, O, Kriegsfeld L. The Pathophysiologic Role of Disrupted Circadian and Neuroendocrine Rhythms in Breast Carcinogenesis. Endocr Rev. 2016 Oct;37(5):450-466.
 Stothard ER, McHill AW, Depner CM, Birks BR, Moehlman TM, Ritchie HK, Guzzetti JR, et al.
By Marc Sorenson, EdD… Sun exposure benefits…
A very important paper regarding the necessity for sun exposure has recently been published by the journal Medical Hypothesis. It is entitled Regular sun exposure benefits health, and it discusses the pros and cons of sun exposure. One of the salient statements in the paper is that intermittent sun exposure may increase the risk of skin cancer, whereas regular exposure to sunlight might benefit health. For those of us who have for years studied the beneficial effects of sun exposure, the use of the word “might” is the only drawback to the statement. There is no doubt that for the majority of the population, regular sun exposure absolutely protects and enhances health.
Among the diseases mentioned as being reduced or prevented by regular sun exposure are the following:
- Cancers: Colon, breast, prostate and non-Hodgkin lymphoma
- Multiple sclerosis
As the authors mention, most of these positive effects of sun exposure were previously ascribed to Vitamin D, but they point out that immune system function is enhanced by sun exposure beyond the effects of vitamin D, and list other non-vitamin D benefits of the sun, including:
- Production of nitric oxide
- Production of melatonin
- Production of serotonin
- Regulation of the circadian clock
I have discussed most of these items on the Sunlight Institute web site, but it was good to see new research that, in particular, separated the health benefits of sun exposure from vitamin D production. The idea that has become popularized during the past decade, that all benefits of sun exposure come from increased vitamin D production, is simply not true and can lead to the supplementation of vitamin D as a “cure” for diseases that may not be influenced by that hormone.
Of course, vitamin D is an exceptionally important photoproduct, and the only natural way to attain it is by exposure to the sun or to other sources of UVB light (such as a sunlamp or a tanning bed). The beauty of using these sources, rather than a vitamin-D capsule, is that all of the benefits of nitric oxide, melatonin, serotonin and circadian entrainment are included in the package.
Safely enjoy the sun, and you then will also safely enjoy better health. Remember not to burn, and to gradually develop a good tan.
 van der Rhee H, de Vries, E, Coebergh, J. Regular sun exposure benefits health. Medical Hypotheses 97 (2016) 34–37
In a new scientific paper, Dr. MS Razzaque shows that there may be some downsides to vitamin D supplementation, including “cardiovascular events and beyond.” He also states that “since hypovitaminosis D status usually reflects reduced sunlight exposure, the obvious primary replacement should be safe sunlight exposure, and not exogenous supplements.”
The paper specifically mentions that avoiding sunlight exposure may influence the initiation and progression of different types of tumors [cancer], high blood pressure, type 1 diabetes and multiple sclerosis. It also points out that there may be some deleterious consequences of vitamin D supplementation, although in my opinion, the dosage would need to by quite high.
As I have indicated in many of my posts on the Sunlight Institute site, sun exposure is the most natural way to obtain vitamin D, and it has no toxicity, since it is self-regulated.
What wasn’t mentioned was the production of health-promoting substances when sun touches the skin, e.g. endorphins and nitric oxide. And of course, the sun helps the brain to produce serotonin and BDNF, which are critical for proper brain function.
So soak up your sunlight but don’t burn.
 Razzaque MS. Sunlight exposure: Do health benefits outweigh harm? J Steroid Biochem Mol Biol. 2016 Sep 16. [Epub ahead of print].
By Marc Sorenson, EdD. Sunlight Institute… promoting safe sun exposure…
It has long been known that vitamin D deficiency is associated with hypertension. But could that association really be a measurement of inadequate sun exposure? A most interesting investigation was carried out this month (July 2016) in which the researchers evaluated over 1100 subjects from an ongoing study called “the Reasons for Racial and Geographic Differences in Stroke.” They measured vitamin D levels and also assessed sun exposure levels, and found that both high vitamin D levels and high sun exposure levels were associated with higher blood pressure.
What makes this research different is that when the data was adjusted for other factors, high sun exposure was even more impressive as a protective factor against high blood pressure. However, adjusting for vitamin D levels had no effect on the association of sun exposure to lower blood pressure; for each increase in sun exposure, there was a corresponding decrease in blood pressure, but the same was not true for increases or decreases in vitamin D levels.
The researchers made this statement: “We conclude that although 25(OH)D concentration is inversely associated with SBP, it did not explain the association of greater sunlight exposure with lower BP.”
To me, this research indicates that sun exposure directly effects lower blood pressure levels, independently of vitamin D. This is not surprising, since clinical trials of vitamin D supplementation have found only small effects on blood pressure.
I hypothesize that nitric oxide (NO), is the mechanism by which sun exerts its impressive effects. NO is a potent vasodilator, and when it is released into the arteries by UVA stimulation, causes increased blood flow and lowers blood pressure.  Dr. Oplander and his colleagues wrote the first paper on the UVA, NO and blood pressure in 2009, and Dr. Richard Weller has been a leader in doing research and granting interviews on NO since that time. He has made two interesting statements: (1) “We suspect that the benefits to heart health of sun will outweigh the risk of skin cancer. The work we have done provides a mechanism that might account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sun.” (2) “Although the benefits of sun are often attributed to vitamin D, a gas called nitric oxide is also important. Made when the sun hits our skin, nitric oxide lowers blood pressure when it enters the bloodstream. Although the reduction is small, it could ‘make a big difference.”
A study from China also demonstrates that exposure to sun correlates to a lowered risk of hypertension. In a randomly selected population of Chinese residents from Macau (where the rate of hypertension is very high), the following risk factors for hypertension were assessed: lack of sun exposure, low intake of fish, smoking, obesity and lack of exercise. An average of more than one-half hour of sun exposure per day compared to none predicted a 40% reduced risk for hypertension.
Vitamin D has many marvelous health effects, but sun exposure per se has many more, because not only does the sun stimulate the production on vitamin D, it also produces other vital photoproducts such as NO, endorphins and serotonin. When we avoid the sun and simply take a vitamin D pill, we are short-changing ourselves for the total package of benefits derived from the sun. And in the case of high blood pressure, we may be receiving almost no benefit from vitamin D. Think about it, and enjoy the sun safely.
 Rostand SG, McClure LA, Kent ST, Judd SE, Gutiérrez OM. Associations of blood pressure, sunlight, and vitamin D in community-dwelling adults. J Hypertens. 2016 Jul 1. [Epub ahead of print]
 Beveridge LA, Struthers AD, Khan F, Jorde R, Scragg R, Macdonald HM, Alvarez JA, Boxer RS. Et. al. Effect of Vitamin D Supplementation on Blood Pressure: A Systematic Review and Meta-analysis Incorporating Individual Patient Data. AMA Intern Med. 2015 May;175(5):745-54.
 Liu D, Fernandez BO, Hamilton A, Lang NN, Gallagher JM, Newby DE, Feelisch M, Weller RB. UVA irradiation of human skin vasodilates arterial vasculature and lowers blood pressure independently of nitric oxide synthase. J Invest Dermatol. 2014 Jul;134(7):1839-46.
 D Liu, BO Fernandez, NN Lang, JM Gallagher, DE Newby, M Feelisch and RB Weller. UVA lowers blood pressure and vasodilates the systemic arterial vasculature by mobilization of cutaneous nitric oxide stores. Photobiology Abstract # 1247 May 2013.
 Opländer C, Volkmar CM, Paunel-Görgülü A, van Faassen EE, Heiss C, Kelm M, Halmer D, Mürtz M, Pallua N, Suschek CV.. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates. Circ Res. 2009;105:1031–40.
 Quoted on Mercola.com http://articles.mercola.com/sites/articles/archive/2013/07/15/sun-exposure.aspx accessed July 2, 2015.
 Weller, R. Shunning the sun may be killing you in more ways than you think. New Scientist July 2, 2015.
 Ke L, Ho J, Feng J, Mpofu E, Dibley MJ, Feng X, Van F, Leong S, Lau W, Lueng P, Kowk C, Li Y, Mason RS, Brock KE. Modifiable risk factors including sun exposure and fish consumption are associated with risk of hypertension in a large representative population from Macau. J Steroid Biochem Mol Biol 2013 Nov 1 [Epub ahead of print].
By Marc Sorenson, EdD. Sunlight Institute…
Canada has a long season each year in which vitamin D from sunlight is not available. Due to the northern latitude of Canada, May through October is the only period when vitamin D can be produced in response to sun exposure to the skin. Therefore, a new press release from the Vitamin D Society recommends to protect health by building up vitamin D during the summer. Vitamin D from the summer sun helps to prevent serious diseases such as cancer, cardiovascular diseases, diabetes, multiple sclerosis and others.
Dr. Reinhold Vieth, the scientific advisor for the Society, states the following: We often assume that the health benefits of sunshine are solely due to vitamin D, but that is not proven yet. In other words, it is likely that sunshine does more for our bodies than just produce vitamin D.”
Dr. Vieth is correct. Vitamin D is only one of several products of sun exposure. Others are nitric oxide, which helps prevent vascular problems, and serotonin and endorphins that enhance mood. It is likely that there are many more products of sun exposure that enhance human health.
The Society recommends 6 guidelines for safely enjoying the sun and its health benefits:
- Be moderate, and don’t burn.
- Sun exposure can produce vitamin D only during the mid-day hours, so be outside between 10 AM and 4 PM.
- Know your skin type and risk of burning. Red hair and very light skin predict a greater risk of burning. (Also remember that dark skin needs more sun exposure to produce vitamin D).
- A gradual build-up of a tan protects the skin from burning.
- When the skin begins to redden, it is time to stop the sun exposure.
- Frequent but shorter sun exposure times are better for producing vitamin D.
Since about 35% of all Canadians do not meet suggested vitamin D requirements, sun exposure is essential to reverse that statistic.
So Canadians, safely enjoy the sun this summer!
To read the entire press release, go to this link: http://www.vitamindsociety.org/press_release.php?id=44
By Marc Sorenson, EdD. Sunlight Institute.
Regular sun exposure is one of the best ways to reduce the risk of many cancers. Although the relationship of sun exposure (and vitamin D) to the risk of prostate cancer is controversial, a study from Australia, published in 2011, showed that the less sun exposure, the greater the risk of the cancer. The researchers investigated the relationship between prostate cancer incidence and solar radiation in non-urban Australia and found an inverse association. There are many other studies that indicate a protective effect of sun exposure. One of the earliest was conducted by Dr. Esther John and her colleagues: they compared the lifetime sun exposure of 450 white men with advanced prostate cancer to that of 455 white men who did not have cancer. The men were divided into quintiles according to the amount of exposure they had received. Subjects in the highest fifth of sun exposure had only 51% of the risk of prostate cancer as did those in the lowest quintile.
Another study on cancer that corroborated these observations was entitled: Is prevention of cancer by sun Exposure more than just the effect of vitamin D? A systematic review of epidemiological studies. In their review, the authors noted that regular sun exposure correlated to a reduced risk of colorectal cancer, prostate cancer, breast cancer and non-Hodgkin’s lymphoma (NHL). However, vitamin D levels correlated to a reduced risk of colorectal, and to a lesser extent, breast cancer, but were not correlated to a significant risk reduction in prostate cancer and non-Hodgkin’s lymphoma. The authors concluded with this statement: “Particularly in prostate cancer and NHL, other sun-potentiated and vitamin D-independent pathways, such as modulation of the immune system and the circadian rhythm, and the degradation of folic acid, might play a role in reduced cancer risk as well.” These researchers did well to remind us, that as important as vitamin D is to the human body, other effects of sun exposure may be more important in some diseases. The authors could have also mentioned the effect of sun on vasodilation, mediated by the production of nitric oxide (produced by the skin after sun exposure). They could also have discussed the influence of sun on production of serotonin and endorphins, all of which may have contributed to their observations.
Other research used childhood sunburn as a measure of UVR exposure and determined that men who had sunburned as children had only about one-fifth the risk of contracting prostate cancer as those who had not sunburned. A note of caution! We are not recommending that anyone sunburn in order to prevent prostate or other types of cancer. Sunburn was used in this research to predict higher vitamin D levels, but it is not necessary to achieve those levels, since non-burning sun exposure achieves the same results. This research also demonstrated that men with lowest level of UVR exposure had more than triple the risk of prostate cancer and that onset of the disease was delayed more than four years in those who had the greatest exposure compared to those who had the least exposure. A follow-up to this study, reported that men in the lowest quartile of sunbathing were linked to a 5.33-fold greater risk of prostate cancer than those in the highest quartile. Still other research has indicated that “higher levels of cumulative exposure, adult sunbathing, childhood sunburn and regular holidays in hot climates were each independently and significantly associated with a reduced risk of this [prostate] cancer.
So men, protect your prostate by regular, non-burning sun exposure. Don’t let the Powers of Darkness frighten you away from the sun.
 Loke TW, Seyfi D, Khadra M. Prostate cancer incidence in Australia correlates inversely with solar radiation. BJU Int. 2012 Apr;109 Suppl 3:75.
 John EM, Schwartz GG, Koo J, Van Den Berg D, Ingles SA. Sun exposure, vitamin D receptor gene polymorphisms, and risk of advanced prostate cancer. Cancer Res 2005;65(12):5470-79.
 van der Rhee H, Coebergh JW, de Vries E. Is prevention of cancer by sun exposure more than just the effect of vitamin D? A systematic review of epidemiological studies. Eur J Cancer. 2013 Apr;49(6):1422-36.
 Moon SJ, Fryer AA, Strange RC. Ultraviolet radiation: effects on risks of prostate cancer and other internal cancers. Mutat Res 2005;571(1-2):207-19.
 Bodiwala D, Luscombe CJ, Liu S, Saxby M, French M, Jones PW, Fryer AA, Strange RC.. Prostate cancer risk and exposure to ultraviolet radiation: further support for the protective effect of sun. Cancer Lett 2003;192:145-49.
Does sun exposure help fight depression? Of course!
By Marc Sorenson, EdD. Sunlight Exposure
Although this blog has discussed sun exposure and its affects on depression, there is some information that I may have neglected to mention. It has been shown that depressed psychiatric patients who resided in sunny rooms stayed in the hospital 2.6 fewer days than those who had “dull” rooms. The sunny rooms had windows, so it is likely that endorphins and serotonin, created by the sun entering the windows, were the natural “uppers” by which the patients felt better. Nitric oxide, produced by UVA light exposure, could also have played a part.
Another of those dull rooms is the one that houses the TV. An interesting study from the University of Pittsburgh found that the more TV teenagers watched, the more likely they were to be depressed as adults. The study author theorized that because there is so much depressing news and programming on TV, the more exposure, the more the internalizing or the depressing programming. For each hour of TV watched, the rate of depression increased significantly.
The researchers may be correct, or it could be that hours of sedentary life in front of the TV, watching commercials for junk food, leads to obesity and poor health as the teenager ages. We have another theory that may supplant, or at least add to those theories. It is possible that years of unnatural indoor habits create deficiency of the aforementioned vitamin D, nitric oxide, endorphins and serotonin, which may have long-term effects. Combined with the deleterious influences of excessive TV watching, that could be a recipe for depression and health disasters. Sun exposure and vitamin D are absolutely necessary for human health and happiness. An indoor lifestyle is unnatural and damaging to the human body and psyche.
Safely embrace the sun and obtain its “feel-good” effects.
 Beauchemin KM, Hays P. Sunny hospital rooms expedite recovery from severe and refractory depressions. J Affect Disord. 1996 Sep 9;40(1-2):49-51.
Primack, B. Association between media use in adolescence and depression in young adulthood: a longitudinal study. Arch Gen Psychiatry. 2009 Feb;66(2):181-8
Sun Exposure, artificial light and weight control. Marc Sorenson, EdD… Sunlight Institute
Sun exposure gives life and has so many positive effects, including anticancer, anti-heart disease, and anti-osteoporosis. Unnatural light, however can do exactly the opposite. In the case of obesity, artificial light at night (ALAN) can lead to weight gain, according to a study in the International Journal of Obesity.
The hormone melatonin works in conjunction with serotonin during each daily physiological cycle, known as the circadian rhythm. Serotonin is a natural “upper” that awakens our senses and prepares us for our workday. Then, when the rhythms are properly synchronized, as evening comes, serotonin decreases and melatonin, a sleep inducer, takes over so that we can sleep soundly and awake refreshed as daylight and serotonin once more take over. However, a monkey wrench is often thrown into the works. It is called artificial light at night (ALAN), and it may be one of many factors that lead to obesity. ALAN inhibits melatonin production, a factor in both obesity and cancer.
The researchers looked at satellite images of 80 countries, assessed the amount of ALAN emitted from each country and then compared the rates of obesity in each. The data was adjusted to take into consideration the differing dietary patterns in each country, as well as the urban vs rural population and other factors that would influence obesity.
The results showed, that after all adjustments, ALAN emerged as a prominent predictor for obesity.
So how does this relate to sun exposure? One of my recent posts noted the results of research on early morning sun exposure and obesity, noting that early sun exposure inhibited obesity dramatically. So not all light is good. Light at night is harmful; early morning sun exposure is wonderful. And if one wants to remain slim, it is imperative to eschew junk food, exercise and get plenty of non-burning sun exposure.
 Rybnikova NA, Haim A, Portnov BA. Does artificial light-at-night exposure contribute to the worldwide obesity pandemic? International Journal of Obesity. Int J Obes (Lond). 2016 May;40(5):815-23.
 Reid KJ, Santostasi G, Baron KG, Wilson J, Kang J, et al. Timing and Intensity of Light Correlate with Body Weight in Adults. PLoS ONE 2014 9(4): e92251. doi:10.1371/journal.pone.0092251