Tag Archives: vitamin d

Sun exposure and Leukemia. Protect yourself from this disease by enjoying the sun!

By Marc Sorenson, EdD  Sunlight Institute…

Leukemia is a cancer of the bone marrow that prevents the normal manufacture of red blood cells, white blood cells and platelets. It can lead to infection, impaired blood clotting and anemia. The good news is that embracing the sun may have a profoundly protective effect against this deadly disease.

Consider this research by Dr. Timo Tomonen and his colleagues that showed a very close relationship between sun deprivation and acute myeloid leukemia.[1] The researchers stated that “During the light season, the incidence decreased by 58% (95% confidence interval, 16–79%) per 1,000 kJ/m2/d increase of solar radiation.” In Finland, It has also been shown that deficiency of sunlight (and perhaps cold weather) was associated with excessive diagnoses when compared to diagnoses in in the sunlit, warm season. Other research has indicated that sun exposure during mothers’ pregnancies reduced the risk of leukemia and other cancers in their children.[2]

Finally, in a laboratory study using UVA irradiation of leukemia cells, it was found that such radiation caused rapid apoptosis (natural cell death) in the exposed cells.[3] UVA, of course, is the major ultraviolet component of the solar radiation that reaches the earth. UVA also has been shown to cause a marked decline in the proliferation of leukemia cells.[4] Proliferation is the process of rapid growth and multiplication of cancer cells. So it appears that sun exposure has two more positive attributes for preventing cancers: it has the ability to hasten the death of cancer cells and to retard the tendency of cancer cells to grow and multiply out-of-control. It is also interesting to note, although the researchers did not mention it, that UVA exposure does not cause the production of vitamin D, which means that some other mechanism of sun exposure was responsible for the positive results. Vitamin D is a wonderful photoproduct of sun exposure, but positive benefits of other photoproducts are available. When we substitute vitamin D supplements for sun exposure we may make a critical mistake and increase our risk of leukemia and other diseases. Nothing is a match for habitual, safe sun exposure, but sun lamps would be a close second.

The sun is a natural protector against leukemia. What more need we say?

[1] Timo Timonen, Simo Näyhä, Tapani Koskela, Eero Pukkala.  Are sun deprivation and influenza epidemics associated with the onset of acute leukemia?  Haematologica 2007; 92 (11):1553-56.

[2] Christina Lombardi, Julia E. Heck, Myles Cockburn, and Beate Ritz. Solar UV Radiation and Cancer in Young Children. Cancer Epidemiol Biomarkers Prev 2013;22:1118-1128.

[3] Zhuang S, Kochevar IE. Ultraviolet A radiation induces rapid apoptosis of human leukemia cells by Fas ligand-independent activation of the Fas death pathways. Photochem Photobiol. 2003 Jul;78(1):61-7.

[4] Leszczynski D, Fagerholm S, Leszczynski K. The effects of the broadband UVA radiation on myeloid leukemia cells: the possible role of protein kinase C in mediation of UVA-induced effects. Photochem Photobiol. 1996 Dec;64(6):936-42.

Read More

New Research sheds more Light on Parkinson’s Disease

By Marc Sorenson, EdD, Sunlight Institute…

A new investigation from Chinese researchers demonstrates that sun exposure is dramatically protective against Parkinson’s disease (PD).[1] The paper reported a study in which 201 newly diagnosed patients were compared with 199 controls who were free of PD. Data on vitamin D intake, blood vitamin D levels and sun exposure were obtained in both groups by using a self-report questionnaire.

For blood vitamin D levels, those who had the highest levels had a 48% lowered risk of PD; for sun exposure, those receiving the greatest exposure had about 47% reduced risk of PD.

Whereas a significant positive correlation existed between blood levels of vitamin D and sun exposure, vitamin D intake from supplements, food, etc. did not correlate to blood levels of vitamin D.

This is a particularly interesting study in that it demonstrates that vitamin D should be raised by exposure to the sun when possible rather than dietary intake. It appears that dietary intake the amounts most people receive is not effective for raising those levels.

The evidence for a protective effect of sun exposure against PD has been building for some time. In 1988, it was observed that when four northern census regions of the U.S. were compared with three southern regions, death rates for PD were significantly higher in the northern regions,[2] indicating a possible protective effect of sun exposure. Later research corroborated those findings, demonstrating a strong north-south decreasing gradient for PD among whites.[3]

There are several more studies indicative of a positive effect of sun on PD, and these will be included in the book on sunlight that Dr. William Grant and I are writing, and which we hope to have published in May. Stay tuned, and safely embrace the sun!

[1] Juan Wang, Deyu Yang, Yu Yu, Gaohai Shao and Qunbo Wang 2. Vitamin D and Sunlight Exposure in Newly-Diagnosed Parkinson’s Disease. Nutrients 2016;8:142.

[2] Kurtzke JF, Goldberg ID. Parkinsonism death rates by race, sex, and geography. Neurology. 1988 Oct;38(10):1558-61.

[3] Lanska DJ. The geographic distribution of Parkinson’s disease mortality in the United States. J Neurol Sci. 1997 Sep 1;150(1):63-70.

Read More

Sun Exposure is more important than Vitamin D to stop Cancer Development.

By Marc Sorenson, EdD, Sunlight Institute…

An impressive research paper on colorectal cancer demonstrates that both vitamin D supplementation and ultraviolet-light (UV) exposure are effective in reducing that cancer.[1] To begin the research, mice that are bred to be susceptible to intestinal tumors were put on a vitamin D-deficient diet, which reduced vitamin D levels significantly and spurred the development of non-cancerous tumors. Then, the diseased animals were either supplemented with vitamin D, or exposed to UV radiation. Remember that UV is the type of non-visible radiation produced by the sun.

In both cases (vitamin D supplementation and UV exposure), the area covered by tumors was significantly reduced. However, only UV exposure reduced the progression of the tumors to malignancy (full-fledged cancer).

The authors made the following statement regarding their somewhat surprising finding:

“Mortality from colorectal cancer decreases as ambient levels of UV radiation increase, suggesting that UV exposure is critical to the prevention of the disease. This study demonstrates the biological plausibility in mice of a causal relationship between moderate chronic UV irradiation or vitamin D supplementation and an impairment of outgrowth of primary intestinal cancer. While both UV irradiation and vitamin D supplementation decreased the overall area covered by tumors, only UV exposure inhibited malignant progression” [emphasis mine].

The Garland brothers in 1980 demonstrated that Sun exposure was inversely associated with colon cancer.[2] They assumed that sun-stimulated vitamin D was the mechanism that caused the inverse association, but it now seems that sun exposure has cancer preventive mechanisms beyond vitamin D.

Remember: sunlight alone will always be better than vitamin D alone, because there are many healthful chemicals, beyond vitamin D, that are produced by sun exposure.

[1] Heggert Rebel, Celia Dingemanse-van der Spek, Daniela Salvatori, Johannes P.T.M. van Leeuwen, Els C. Robanus-Maandag and Frank R. de Gruijl. UV exposure inhibits intestinal tumor growth and progression to malignancy in intestine-specific Apc mutant mice kept on low vitamin D diet. Int J Cancer. 2015 Jan 15;136(2):271-7.

[2] Garland CF, Garland FC. Do sunlight and vitamin-D reduce the likelihood of colon cancer? Int J Epidemiol 1980;9:227–31.

Read More

Does Lack of Sun Exposure contribute to deadly Sepsis?

By Marc Sorenson, EdD, Sunlight Institute…

Sepsis is a deadly disease, defined as infection of the tissues by bacteria. It can spread throughout the body and blood, where it is known as septicemia.  Sepsis accounts for 500,000 emergency-room hospital visits per year in the USA, and the typical stay is nearly five hours.[1] It is one of the most deadly of medical conditions and often results in multiple organ failure.[2] It is, in fact, one of the top-ten causes of death. It is more common than heart attack, and claims more lives than any cancer.[3] Yet, much of the population has never heard of it.

Antibiotics have not been effective against severe sepsis and in some cases may exacerbate the disease.1 Sepsis is also the most common cause of death in critical-care patients in non-coronary intensive care units.[4]

Does regular time in the sun act to protect against this deadly disease? The research indicates that it does. In both the USA and UK, the disease is more common in winter than summer and higher in the Northeast than in the Southwest.

It is likely that vitamin D, produced by sun exposure, is the mechanism by which sepsis risk is decreased in summer.[5] According to Dr. William Grant, reports have shown that vitamin D upregulates human cathelicidin, LL-37, which has antimicrobial as well as anti-endotoxin activity.[6] However, we must never lose sight of the other benefits of sun exposure beyond vitamin D, which is only one of the sun’s beneficial photoproducts. Staying out of the sun—and using deadly chemical sunscreens to block life-giving sun exposure—are two of the biggest blunders ever made in the history of health disasters.

It is also interesting to note that in Australia, melanoma rates skyrocketed between 1980 and 2000.[7] 1980 was the year when a massive anti-sun campaign, called “Slip, Slop, Slap” began. Sepsis rates jumped simultaneously with melanoma and coincided with the widespread use of sunscreens. During this campaign, there was also an increase in viral respiratory infections, most cancers, and congestive heart failure.[8]

Remember that hospitals are not sterile environments. Try to stay away from them except in cases of dire need. Get some moderate, non-burning midday sun exposure instead—without using sunscreens.

[1] Wang, H. et al.  National estimates of severe sepsis in United States emergency departments.  Crit Care Med 2007;35:2461-2.

[2] Mookherjee, N. et al.  Cathelicidins and functional analogues as antisepsis molecules. Expert Opinions on Therapeutic Targets 2007;11:993-1004.

[3] World Sepsis Day web page. September 13, 2015. http://world-sepsis-day.org/?MET=SHOWCONTAINER&vCONTAINERID=11. Accessed February 25, 2016.

[4] Florian B Mayr, Sachin Yende, and Derek C Angus. Epidemiology of severe sepsis. Virulence 2014, 5:1, 4-11.

[5] Karin Amrein, Paul Zajic, Christian Schnedl, Andreas Waltensdorfer, Sonja Fruhwald, Alexander Holl,

Tadeja Urbanic Purkart, Gerit Wünsch, Thomas Valentin, Andrea Grisold, Tatjana Stojakovic, Steven Amrein, Thomas R Pieber and Harald Dobnig. Vitamin D status and its association with season, hospital and sepsis mortality in critical illness. Critical Care 2014, 18:R47

[6] Grant WB Solar ultraviolet-B irradiance and vitamin D may reduce risk of septicemia. Dermatoendocrinol. 2009 Jan;1(1):37-42.

[7] Montague M, et al. Slip! Slop! Slap! and SunSmart, 1980-2000: Skin cancer control and 20 years of population-based campaigning. Health Educ Behav. 2001;28:290–305

[8] Grant WB Solar ultraviolet-B irradiance and vitamin D may reduce risk of septicemia. Dermatoendocrinol. 2009 Jan;1(1):37-42.

Read More

Lack of Sun Exposure is an important Factor in Premenopausal Breast Cancer

By Marc Sorenson, EdD, Sunlight Institute…

Case-control research from Iran indicates that lack of sun exposure is a major risk factor for breast cancer.[1] Two groups of women, one that had breast cancer (cases) and another that was normal (controls), were assessed by questionnaire regarding lifestyle choices and the risk for breast cancer. When assessing sun exposure habits, those who had the lowest level of sun exposure had nearly three times the risk of being a cancer victim as those who had the highest level.

This is the second Iranian study I am aware of that showed a remarkable difference in breast-cancer risk based on sun exposure. Another case-control study showed that women who covered themselves completely had more than 10 times the risk breast cancer compared to those who were not totally covered.[2] Of transcendent importance was the unexpected finding that vitamin D levels were nearly identical in cases as controls, meaning that the protective mechanism could not have been vitamin D. Some other factor must have protected them from the disease. We have mentioned on this blog many times that sun exposure leads to higher levels of serotonin, endorphin, nitric oxide and other potentially helpful products.

Whatever the mechanism, it seem wise to get plenty of non-burning sunlight.

[1] Salarabadi A, Bidgoli SA, Madani SH. Roles of Kermanshahi Oil, Animal Fat, Dietary and Non- Dietary Vitamin D and other Nutrients in Increased Risk of Premenopausal Breast Cancer: A Case Control Study in Kermanshah, Iran. Asian Pac J Cancer Prev. 2015;16(17):7473-8.

[2] Bidgoli SA, Azarshab H. Role of vitamin D deficiency and lack of sun exposure in the incidence of premenopausal breast cancer: a case control study in Sabzevar, Iran. Asian Pac J Cancer Prev. 2014;15(8):3391-6.

Read More

Sun Exposure, Nitric Oxide and Vitamin D for improved Athletic Performance

By Marc Sorenson, EdD  Sunlight Institute…

A most interesting research paper demonstrates that nitrate supplements, combined with exposure to sunlight, increases performance of cyclists.[1] The researchers state that “dietary nitrate supplementation has been shown to increase nitric oxide (NO) metabolites, reduce blood pressure (BP) and enhance exercise performance.” And, as we have discussed in this blog, sun exposure reduces BP by increasing the production of NO. It was theorized that sun exposure might enhance the athletic performance induced by the dietary nitrate supplementation.

The theory proved to be correct; although sun exposure did not improve cycling times by itself, when combined with the nitrate supplementation, cycling times improved significantly.

It may surprise some people to realize that ultraviolet radiation (UVR) from sun beds or sun lamps has been used since before 1950 to enhance athletic performance.[2] As early as 1938, Russian researchers reported that a course of UVR significantly improved speed in the 100-meter dash among four students when compared with controls that did not have the radiation, although both groups were undergoing identical daily training.[3] The non-irradiated group improved by 1.7% but the irradiated group improved by 7.4%. Another study conducted over ten weeks showed that cardiovascular endurance improved remarkably among athletes in training who were irradiated vs. those who were not.[4] The irradiated athletes improved by 19.2% compared to 1.5% among the non-irradiated group.

There are numerous studies from Germany showing the efficacy of UVR on athletic performance, most of them from the early days before the idea of sun-lamp produced UVR fell into disrepute because of the attack on tanning beds. What a shame. This method of athletic assistance could produce an impressive improvement in sports performance for so many people, athletic or not. Strength improves, stamina improves, quickness improves and speed improves with UVR radiation, which of course is also part of sunlight. The mechanism for this improvement is likely a combination of vitamin D and nitric oxide.

Safely enjoy the sun!




[1] Muggeridge DJ, Sculthorpe N, Grace FM, Willis G, Thornhill L, Weller RB, James PE, Easton C. Acute whole body UVA irradiation combined with nitrate ingestion enhances time trial performance in trained cyclists. Nitric Oxide. 2015 Aug 1;48:3-9.

[2] Cannell JJ, Hollis BW, Sorenson MB, Taft TN, Anderson JJ. Athletic performance and vitamin D. Med Sci Sports Exerc. 2009 May;41(5):1102-10.

[3] Gorkin Z. Gorkin MJ, Teslenko NE. The effect of ultraviolet radiation upon training for the 100-meter sprint.

[4] Allen R, Cureton T. Effects of ultraviolet radiation on physical fitness. Arch Phys Med 1945;10:641-4.

Read More

Sunlight and Vitamin D associate with a reduced risk of Leukemia. Or is it really only Sun Exposure?

By Marc Sorenson, EdD  Sunlight institute…

Recent research shows that there is a higher risk of leukemia in countries that are at high latitudes in the north or low latitudes in the south. The risk is twice as high at these latitudes as at latitudes closer to the equator.[1] Dr. Cedrick Garland, one of the authors of the research, stated that “these results suggest that much of the burden of leukemia worldwide is due to the epidemic of vitamin D deficiency we are experiencing in winter in populations distant from the equator.” Since persons living far from the equator have much less exposure to the sun’s rays, due to shorter sunlight seasons and more cloudiness, the statement regarding vitamin D deficiency makes sense; UVB from sun exposure, or another source such as tanning lamps, is necessary to stimulate the skin to produce vitamin D—hence the association between latitude and vitamin D.

However, Dr. William B Grant sent me an interesting paper that leads me to believe that some things that seem to make sense may not necessarily be true. The paper showed that there was little difference among vitamin D levels in countries at different latitudes,[2] with levels being close to 20 ng/ml on average. This would lead me to believe that vitamin D was not the factor that caused the reduced risk of leukemia among the countries that received more sunlight.

We are then left to determine the cause of the reduced risk of leukemia in the sunny countries. There are really only two factors that come to mind. First, sunlight, through the eyes, stimulates the production of serotonin/melatonin, which have been associated with protection against cancer in some studies. Sunlight also stimulates the skin to produce nitric oxide and endorphin, which could have an impact. Second, populations residing in areas closer to the equator are likely to have access to year-round fruits and vegetables, which have been shown to associate to a lower risk of cancer. Whatever the reason, this is one more example of better health among people who receive more sunlight. And remember, even those fruits and veggies need sunlight to thrive. So let’s safely embrace the sun.

[1] Cuomo RE, Garland CF, Gorham ED, Mohr SB. Cuomo RE, Garland CF, Gorham ED, Mohr SB. Low Cloud Cover-Adjusted Ultraviolet B Irradiance Is Associated with High Incidence Rates of Leukemia: Study of 172 Countries. PLoS One. 2015 Dec 4;10(12). 

[2] Jennifer Hilger, Angelika Friedel, Raphael Herr, Tamara Rausch, Franz Roos, Denys A. Wahl, Dominique D. Pierroz, Peter Weber and Kristina Hoffmann. A systematic review of vitamin D status in populations worldwide. Br J Nutr. 2014 Jan 14;111(1):23-45.



Read More

Sunshine, Obesity and Bone Loss

By Marc Sorenson, EdD  Sunlight Institute…

The obesity pandemic, brought about by horrendous eating patterns, lack of exercise and lack of sunlight, has spawned millions of nutritionally bizarre diet programs and numerous strange medical procedures. One of the strangest is gastric bypass surgery, a procedure that cuts calorie absorptions by bypassing part of the stomach and intestinal area that absorbs nutrients. It is another case, similar to open-heart bypass, of a surgery that “bypasses” the real problem: preposterous lifestyle habits.

Any thinking person realizes that a surgery that reduces the calorie absorption also reduces the absorption of calcium and dietary vitamin D. It is a recipe for osteoporosis and hip fractures; these nutrients are essential for optimal bone health. Research by Dr. J Fleischer and colleagues showed that one year after gastric bypass, bone loss at the hip was 8%.[i] Just how important is this finding?  One assessment showed that the risk of fracture increases two to three times for every 10 percent drop in bone density,[ii] and another showed that for every loss of 0.12g (.043 oz)  per square centimeter (.15 square inch) of bone mass, the risk of a fracture increased by 360% in women and 340% in men.[iii] 

Remember that this bone loss was reported only one year after the bypass surgery. If this rate of bone loss continued for several years, it would weaken the skeleton to the point that the slightest movement would cause a fracture. The bypass procedure is a horror, and the bone loss brought on by lack of absorption of calcium and vitamin D is even worse.

In the case of decreased absorption of vitamin D, increased dietary intake of vitamin D may not work to improve bone strength; it is likely that only a very small quantity of the increased intake would be absorbed into the system, meaning that the only way to ensure adequate vitamin D levels in the blood is to expose the skin to sunlight around midday in summer or light from sunlamps in winter. Vast quantities of vitamin D are produced in this manner, and the entire quantity is delivered to the blood, where it can work to increase calcium absorption in both the intestine and the bone. Calcium absorption in the intestine, for example, is 65% higher in people whose vitamin D levels are at the high end of “normal” when compared with those who are at the low end of normal.[iv]

Osteoporosis is not inevitable, and it is to a certain extent reversible. It is a problem caused by sunlight deficiency, excessive protein consumption, smoking, and lack of activity. Now we have added another revolting cause: the doctor’s scalpel. I wonder just how many doctors advise their patients about bone loss, sunlight and vitamin D before performing this atrocity. Interestingly, however, sunlight exposure has a positive influence on gastric bypass. Adverse effects of these surgeries are directly associated with the season and latitude in which they occur.[v] Seasons or latitudes of low sunlight availability were inversely correlated to prolonged stays in the hospital (39.4% longer stay), increased dehiscence (bursting open of a surgically closed wound) and wound infection. This surgery is a horror to begin with, but if it must be done, it appears that one should have it done in a sunny season of the year, or at a sunny latitude.

An ounce of prevention is worth tons of cure in the case of obesity. Good nutrition and ample sunlight exposure is essential to optimal human health.

[i] Fleischer JStein EMBessler MDella Badia MRestuccia NOlivero-Rivera LMcMahon DJSilverberg SJ. The decline in hip bone density after gastric bypass surgery is associated with extent of weight loss. J Clin Endocrinol Metab. 2008 Oct;93(10):3735-40.

[ii] Nguyen T, Sambrook P, Kelly P, Jones G, Lord S, Freund J, Eisman J. Prediction of osteoporotic fractures by postural instability and bone density.  BMJ 1993;307:1111-15.

[iii] Nguyen ND, Pongchaiyakul C, Center JR, Eisman JA, Nguyen TV. Identification of high-risk individuals for hip fracture: a 14-year prospective study.  J bone Miner Res 2005;20:1921-28.

[iv] Heaney RP, Dowell MS, Hale CA, Bendich A. Calcium Absorption Varies within the Reference Range for Serum 25-Hydroxyvitamin D.  J Am Coll Nutr 2003;22:142-46.

[v] Petersen L, Canner J, Cheskin L, Prokopowicz G, Schweitzer M, Magnuson T, Steele, K. Proxy measures of vitamin D status—season and latitude, correlate with adverse outcomes after bariatric surgery in the Nationwide Inpatient Sample, 2001-2010; a retrospective cohort study. 2015;9:88-96.

Read More

It’s a SAD Time of Year in Canada and the U.S. Can we cure it with Vitamin D?

By Marc Sorenson, EdD, Sunlight Institute…

A recent press release from the Vitamin D Society of Canada discusses the need for vitamin D in the winter, in order to reduce the risk and intensity of seasonal affective disorder, or SAD. SAD is a feeling of low motivation, depressed mood, decreased concentration, anxiety and despair.

Dr. Samantha Kimball, the scientific advisor for the Society, has found that increasing vitamin D intake can help reduce the symptoms of SAD. She mentions that vitamin D, which is generated in the body by sunlight exposure, can modulate the immune system and reduce inflammation, thereby reducing the risk of depression.

Dr. Kimball is correct; the change can be absolutely dramatic based on serum vitamin D levels. One remarkable piece of research showed that those persons who had the lowest levels of D had almost 12 times as likely to be depressed as those who had the highest levels.[1]

Although I fully agree with Dr. Kimball, I can’t help but wish she had mentioned more on the benefits of the sunlight or even sunlamps, which are the most natural ways to increase vitamin D, but are also marvelously effective in improving mood beyond vitamin D.

In addition to vitamin D, there is a chemical produced by the brain in response to sunlight exposure to the eyes. It is called serotonin and is a natural “upper” or mood enhancer. It is also a neurotransmitter and is available to us from bright light entering the eyes. Even is Canada in winter, when there is no vitamin-D stimulating potential in sunlight, just being outdoors when there is sunshine will work to improve or prevent SAD.  Sunlight can dramatically increase serotonin levels in the brain.

Dr. Gavin Lambert and his colleagues in Australia measured serotonin levels in response to varying degrees of bright light.[2] To do this, they drew blood samples from the internal jugular veins of 101 men and compared the serotonin concentration of the blood to weather conditions and seasons. The results were remarkable: Men who were measured on a very bright day produced eight times more serotonin than those who were measured on a cloudy, dismal day. They also observed that the effect of bright light was immediate, and that there was no holdover from day to day. Serotonin levels were also seven times higher in summer than winter. There we have another answer to SAD. When the sun is shining, wherever you are, take advantage of it. It will elevate your mood and make you feel more alive. And remember that tanning beds and other types of sunlight do a great job of increasing your vitamin D when the sun doesn’t shine. Finally, bright, full-spectrum lighting will also enhance your mood. Merry Christmas and HAPPY Holidays!

Click this link to read the Vitamin D Society press release: http://www.vitamindsociety.org/press_release.php?id=39


[1] Wilkins CH, Sheline YI, Roe CM, Birge SJ, Morris JC. Vitamin D Deficiency Is Associated With Low Mood and Worse Cognitive Performance in Older Adults.  Am J Geriatr Psychiatry 2006;14:1032–1040).

[2] Lambert GW, Reid C, Kaye DM, Jennings GL, Esler MD. Effect of sunlight and season on serotonin turnover in the brain. Lancet. 2002 Dec 7;360(9348):1840-2.

Read More

Fascinating Research “reveals” the Reason that Summer is the healthful Season.

By Marc Sorenson, EdD…

Although most of the readers of this blog probably know why people are healthier and happier during summer, new research show that at least part of the reason in that human immunity is stronger during that season.[i] An interesting anti-inflammatory transcription factor, called ARNTL, has about 50% greater gene activity levels in the summer than in the winter. This would mean that infectious diseases would be more likely to be squelched in the summer, and it could provide a reason for the excess of inflammatory diseases like influenza in the winter. Of course, vitamin D levels and sunlight exposure are also lower in winter, and it is likely that these factors work in concert.

One of the researchers, John Todd, stated the following regarding sunlight exposure, inflammation, and vitamin D. “Given that our immune systems appear to put us at greater risk of disease related to excessive inflammation in colder, darker months, and given the benefits we already understand from vitamin D, it is perhaps understandable that people want to head off for some ‘winter sun’ to improve their health and well-being.”[ii]

Dr. Todd’s advice sounds great to me. Let’s all head to Cabo to catch some life-saving sunlight!

[i] Xaquin Castro Dopico, Marina Evangelou, Ricardo C. Ferreira, Hui Guo, Marcin L. Pekalski, Deborah J. Smyth, Nicholas Cooper,                Oliver S. Burren, Anthony J. Fulford, Branwen J. Hennig, Andrew M. Prentice, Anette-G. Ziegler, Ezio Bonifacio, Chris Wallace & John A. Todd. Widespread seasonal gene expression reveals annual differences in human immunity and physiology. May 2015.

[ii] Agata Blaszczak-Boxe. People Are Healthier in the Summer (and Here’s Why).  http://www.livescience.com/50806-seasonal-variation-human-genes-immune-inflammation.html

Read More
1 6 7 8 9 10 20