By Bob Berman–
Vitamin D, produced when skin is exposed to light, is essential for our bodies. Unfortunately, modern lifestyles have minimized our time we spend under the sun. The Sun’s Heartbeat explains why a tan isn’t as bad as previously thought.
The first scenes in one Sun-tragedy unfolded long before there were written records of any kind. Spurred by events we can only guess at, a human exodus began 50,000 to 70,000 years ago, when our ancestors migrated away from the tropics and the equatorial region’s strong sunlight. Immediately, people developed vitamin D deficiencies.
Our bodies make vitamin D when our skin is struck by the Sun’s ultraviolet rays. Because UV intensity declines dramatically with lower Sun angles, people in temperate regions, and especially those in even higher latitudes, receive as little as 10 percent of the UV experienced by those near the equator. As our ancestors migrating north developed vitamin D deficiencies, the results were swift and brutal. They were removed from the breeding pool by a cruel Darwinian process: the fetus inside a woman with rickets (a disease resulting from low vitamin D) is unable to emerge from her body, and both die in childbirth.
Within just a few thousand years, natural selection had turned some people’s skin white, and they were now able to manufacture ample vitamin D even from the reduced Sun intensity of the higher latitudes. (Dark skin color, called melanin, is a sunblock, needed because naked bodies near the equator can suffer from too much ultraviolet exposure.) In North America and northern Europe, the climate is sufficiently warm that their skin was almost fully exposed for more than half the year, and their bodies stored vitamin D in the muscle and fat. A new balance had been restored.
But starting a century ago, everything changed. First, the United States and Europe went from a mostly outdoors agrarian society to a mostly indoors manufacturing one. Then people started driving around in vehicles surrounded by windows. Glass prevents any vitamin D production because it blocks the Sun’s UV. When air-conditioning became widely available starting in the late 1950s and then got cheaper in the 1970s, people stopped keeping their windows open. Fixed- pane units became increasingly popular. The only sunlight that reached us in our homes and workplaces came through UV-stopping glass.
The last straw was sunblock. It did not even exist until thirty years ago. The initial UV- reducing creams, which cut exposure only in half, were marketed in the 1950s to promote tanning, not totally screen out ultraviolet rays. Then, in the 1980s, a new product came on the market: sunblock. With SPF (sun protection factor) numbers such as 30 and 45, sunblock essentially stops the body’s vitamin D production cold. At the same time, people were advised to cover themselves with these lotions throughout the summer months. Even the medical establishment urged hiding from the Sun as a way to counter skin cancer.
The metamorphosis was complete: we had become like the Morlocks in H. G. Wells’s book The Time Machine, shielded almost totally from sunlight’s UV.
Enter modern vitamin D researchers such as John Cannell, MD, executive director of the Vitamin D Council, a nonprofit educational corporation that believes that “many humans are needlessly suffering and dying from Vitamin D Deficiency.” Cannell is no ordinary medical doctor. He’s no ordinary researcher either. He is a proselytizer, the first in the theater to shout “Fire!” when the smoke appears, while there’s still time to get out. And these days, he’s very, very passionate. He believes that human beings have unwittingly transformed themselves into something uniquely and self- destructively unnatural.
“We are the first society of cave people,” he lamented to me in 2010. “In the development process of creating the skin, nature never dreamed that we’d deliberately avoid the Sun so thoroughly.”
What Cannell and a growing legion of researchers are decrying are the past three decades of newspaper and TV scare stories that have made the public afraid of the Sun. The consequence, they believe, is that our blood’s natural vitamin D levels are just a tiny fraction of what nature intended. And this is producing an avalanche of horrible consequences that include vastly increased rates of cancer.
That vitamin D is super-important is no longer in doubt. It has become the new needed supplement, recommended increasingly by family doctors and the popular media alike. The March 2010 Reader’s Digest calls vitamins in general “a scam” and urges people to take no daily supplements whatsoever – with the single exception of 1,000 international units (IU) of vitamin D3, the form most recommended as a supplement.
This sudden interest has been sparked by a spate of studies strongly indicating that vitamin D is the most powerful anticancer agent ever known. Robert Heaney, MD, of Creighton University, a vitamin D researcher, points to thirty- two randomized trials, the majority of which were strongly positive. For example, in a big study of women whose average age was sixty-two, subjects who were given a large daily vitamin D supplement enjoyed a whopping 60 percent reduction in all kinds of cancers after just four years of treatment compared to a control group.
The skeptical might well wonder how, when cancer typically takes decades to develop, such a huge drop can be detected after just a few years. Heaney believes it’s because vitamin D prevents tiny predetectable tumors from growing or spreading. “That’s the kind of cancer I’d want to have – one that never grows,” he told me in June 2010.
The Canadian Cancer Society raised its vitamin D intake recommendations to 1,000 IU daily in 2009. But Cannell, Heaney, and others think that even this is still way too low.
“I went to a conference and asked all the researchers what they themselves take daily and give to their families,” Heaney said. “The average was 5,500 IU daily. There is certainly no danger in doing this, since toxicity cannot arise in under 30,000 IU a day.”
Why is this vitamin D craze happening now? It sounds suspiciously familiar – like the antioxidant craze of the 1990s, when everyone was gobbling vitamin E to guard against “free radicals.” Or the Linus Pauling– led vitamin C frenzy of the 1970s. Recent studies have shown that all those vitamins have no effect on mortality whatsoever. Indeed, a multivitamin a day now seems to be no better for your health than gobbling a daily Hostess Twinkie. Perhaps our bodies were not designed to get flooded with vitamins. Or maybe the couple of dozen known minerals and vitamins are only the tip of the health iceberg, and what’s important are hundreds, or perhaps thousands, of trace substances of which we are not yet even aware.
Yet it is here, in a discussion of the natural environment in which our bodies were fashioned, that vitamin D makes so much sense. After all, our bodies create it naturally out of the Sun’s ultraviolet rays.
Spending just ten minutes in strong sunlight – the kind you get from 11:00 AM to 3:00 PM between April and August – will allow your body to make as much vitamin D as you would get from drinking two hundred glasses of milk. This is astonishing. Asks John Cannell rhetorically, “Why does nature do this so quickly? Nature normally doesn’t do this kind of thing.”
The implied answer, of course, is that we were designed to have a high and steady level of this vitamin in our bodies. Yet as more and more people are tested, researchers are finding serious vitamin D deficiencies in virtually all of the population of the United States, Canada, and northern Europe. The reason? According to Cannell and the other doctors on the Vitamin D Council, we have been hiding from the Sun for decades.
The results may be even worse than we realize. Many researchers now fear that the explosive increase in autism is a result of pregnant mothers having close to no vitamin D in their bodies and then young babies and infants being similarly shielded from the Sun. The Centers for Disease Control (CDC) says that virtually no infants are getting enough vitamin D. The inadequacy figures, even using the CDC’s pre-2011 lower recommendations of what they thought the body should have, was that 90 percent of infants are deficient.
According to Cannell, the highest autism rates occur in areas that have the most clouds and rain, and hence the lowest blood levels of vitamin D. A Swedish study has strongly linked sunlight deprivation with autism. Moreover, blacks, whose vitamin D levels are half those found in whites living at the same latitudes, have twice the autism rates. Conversely, autism is virtually unknown in places such as sunny Somalia, where most people still spend most of their time outdoors. Yet another piece of anecdotal evidence is that autism is one of the very few afflictions that occur at higher rates among the wealthier and more educated – exactly the people most likely to be diligent about sunscreen and more inclined to keep their children indoors.
As we saw in assessing links between earthly events and sunspot fluctuations, it’s perilous to assign connections too quickly, and autism in particular is a can of worms. Nonetheless, these early threads should set off alarms: it might be wise for pregnant women and mothers of small children to immediately start exposing themselves and their kids to more sunlight.
When Cannell was in medical school in 1973, he was taught that human breast milk contains little or no vitamin D. “This didn’t make sense,” he said during a phone conversation with me in 2011. “Why would nature ever deprive a nursing infant of this vital substance?” Then it came to him: “When pregnant women start taking 5,000 international units of vitamin D daily, their milk soon contains enough vitamin D for a breast-feeding baby. So there’s the key to how much a woman should naturally be getting every day.”
In contrast to all this, and to the great annoyance of physicians and researchers on the Vitamin D Council, the FDA continued to advise only 400 IU of D3 daily as of early 2011. The agency officially regards most vitamin D studies as “incomplete” or “contradictory” and clearly has taken a cautious, go-slow approach.
In November 2010, the National Academy of Sciences’ Institute of Medicine issued its first new recommendations about the vitamin since 1997, and many people were disappointed. The institute did boost its recommended daily amounts to 400 IU for infants, 600 IU for most adults, and 800 IU for those over age seventy. It also said there was no harm in taking up to 10,000 IU daily, although it conservatively adopted 4,000 IU as the official recommended upper limit.
According to Cannell, the new recommendations are still “irrelevant dosages.” Michael Holick, MD, of Boston University, another vitamin researcher, agreed, saying that he personally takes 3,000 IU daily.
Cannell told me that the National Academy of Sciences report was a “scandal” and that four physicians had disgustedly resigned from the committee that put out the paper. “Commonsense aspects are totally lacking,” he said. “For example, they urge infants to get 400 IU daily, but adults just 600 IU. Yet this vitamin is distributed in muscle and fat. The more you weigh, the more you should be getting. It doesn’t make sense.”
“Listen,” he added, “everyone knows that there is an explosion of childhood cases of autism, asthma, and autoimmune disease. It all began when we took our children out of the Sun. Starting twenty-five years ago, a perfect storm of three events has changed how much sunlight children get. First came the scare of childhood sexual predators in the early eighties, then the fear of skin cancer, and finally the Nintendo and video game craze. Nowadays, kids do not play outdoors. Playgrounds are empty. You’re a bad mother if you let your child run around. And it’s almost a social services offense if your kid gets a sunburn. Never before have children’s brains had to develop in the absence of vitamin D.”
Since this is not a medical book, I can only pass on the recommendations of those in the forefront of vitamin D research. Their best advice is to go in the Sun regularly without burning. Wear as little clothing as you can. You know how much Sun you can han-dle without turning red. Unless you have a very light complexion and blond or red hair, you should be able to expose yourself safely to ten to twenty minutes of strong sunlight at a time. Lie out in the Sun in shorts for five to ten minutes on each side. The key to UV intensity is Sun height. If your shadow is shorter than you are, your body will produce a good amount of vitamin D.
After experiencing twenty minutes of unprotected midday Sun from May to July, or a full hour or more during March, early April, and late August through October, you can certainly use sunblock. The experts say to buy the kind whose active ingredient is either zinc or titanium oxide. Most other kinds will be absorbed by the skin, then enter the bloodstream and circulate. “You might as well drink the stuff,” Cannell says disdainfully.
During the low-Sun winter months, you need to spend much more time sunbathing and probably take a vitamin D supplement. The experts are currently urging 2,000 to 3,000 IU daily.
Why not skip the Sun altogether and just pop the pills year- round? Some doctors, including those responsible for the 2010 National Academy of Sciences report, suggest doing exactly that. They figure that you can have it all – nice, high vitamin D serum levels plus no UV exposure, with its skin cancer risk. But others believe that’s a bad idea. “Some of my colleagues think D3 supplements are enough,” Cannell says. “But that supposes we know everything. I suspect that we do not know everything. Natural sunlight has to be the preferred route whenever possible.”
Everyone should use solar power wisely and not go totally bonkers. There’s no need to fry. But whatever extra skin cancer risk we might assume certainly seems to me to be a reasonable price to pay, considering the benefits. It now appears that adequate sunlight- mediated vitamin D might prevent as many as 150,000 cancer deaths a year in the United States alone and also reduce infections, bone problems, and perhaps, though more science is needed, even autism and asthma rates. Of course, on the other side of the balance beam, melanoma causes 8,500 US deaths a year. Every activity from bicycle riding to barroom brawling involves some balancing of risks, and the decision of what trade- offs to make is, of course, yours alone.
Tomorrow is a new day. As the Sun rises, its orange beams will cast magical rays in the morning mist. Is the Sun our enemy or our friend? Will it take our life or save it?
By: Marc Sorenson–
A 2010 study from France has shown that women who were exposed to a combination of sunlight and dietary vitamin D had up to a 45 percent reduced risk of contracting breast cancer, according to Cancer Epidemiol, Biomarkers & Prevention.
The researchers noted that high dietary vitamin D by itself did not correlate to a reduced risk of breast cancer, whereas sunlight exposure alone did correlate to a lowered risk.
This research should come as no surprise, as there is miniscule vitamin D in the typical diet. For example, the typical 3½-ounce piece of farmed salmon contains about 175 International Units of vitamin D; 8 ounces of fortified milk 100 IU; and 8 ounces fortified orange juice 100 IU. The amounts typically derived from eggs, oils and margarine is negligible.
It is now believed by many experts in the vitamin D field that 4,000-5,000 IU of vitamin D supplementation is necessary for optimal health, so it can be seen that trying to optimize breast health with the paltry 400-500 IU from diet is like trying to color the ocean with a cup of tomato paste.
Conversely, 20 minutes of full-body exposure to summer sunlight at noon can produce as much as 20,000 IU, according to a 2005 Journal of Nutrition article, showing that sunlight correlates far better to lowered breast cancer risk than does dietary vitamin D.
However, most people are not actively seeking the sunlight and are not even close to producing 20,000 IU. In the French breast cancer study, it was probably the combination of both sunlight-produced vitamin D and dietary vitamin D that sufficiently increased blood levels to a threshold that triggered vitamin D’s cancer protection mechanisms, which are numerous.
Other research including a 2007 study by The American Journal of Clinical Nutrition, has shown that when vitamin D supplementation is more than 1,100 IU daily, there is a profound correlation to a lowered risk — from 60-77 percent — of all cancers in women.
As to sunlight, Dr. Esther John and colleagues conducted research on the sun-exposure habits of women and correlated those habits to the risk of developing breast cancer. Those women who had the greatest exposure to sunlight were 65 percent less likely to develop breast cancer.
Should we then shun the sunlight? This newest study is another in a long series of vitamin D/cancer research that has shown a striking lowering of breast cancer incidence with higher sunlight exposure and greater vitamin D levels in the blood. The sunlight is one of St. George’s greatest assets and should be embraced, not shunned.
After the Institute of Medicine made their inanely low recommendations for vitamin D supplementation — 600 IU daily for all ages — it is good to see that research belying that foolishness continues to surface.
Sunlight exposure is the most natural way to produce vitamin D and if supplements are going to be used when sunlight is not available, a minimum of 2,000-4000 IU daily is necessary to optimize blood levels for best health. Check with your physician before making changes in sunlight exposure or vitamin D intake.
Marc Sorenson is a resident of St. George. He and his wife, Vicki, founded National Institute of Fitness, in Ivins. They helped thousands of people from all over the world with fitness, weight issues and degenerative diseases. Marc Sorenson received his doctorate from Brigham Young University. He is an author, speaker and founder of the Sunlight Institute, as well as executive director of the Vitamin D Health Initiative.
Log onto vitaminddoc.com or e-mail email@example.com for more information.
By: Nerich V, Jantchou P, Boutron-Ruault MC, Monnet E, Weill A, Vanbockstael V, Auleley GR, Balaire C, Dubost P, Rican S, Allemand H, Carbonnel F
Low sunshine exposure might contribute to the pathogenesis of inflammatory bowel disease (IBD). To assess the geographic distribution of IBD incidence in relation to sunshine exposure in France to test the hypothesis that higher sun exposure is associated with lower IBD risk.
Using the national health insurance database, incidence rates of Crohn’s disease (CD) and ulcerative colitis (UC) were estimated for each of the 94 French administrative areas (‘départements’), between 2000 and 2002. The surface UV radiation intensity was obtained by combining modelling and satellite data from Meteosat, the European meteorological satellite.
Relationships between incidence rates and sun exposure were tested for significance by using a Poisson regression. We mapped smoothed relative risks (sRR) for CD and UC, using a Bayesian approach and adjusting for sun exposure, to search for geographical variations.
Areas with a smoothed RR of CD incidence significantly above 1 corresponded to areas with low sunshine exposure, whereas those with high or medium sunlight exposure had smoothed RRs either lower than 1 or not significantly different from 1. There was no association between sun exposure and UC incidence.
This geographic study suggests that low sunlight exposure is associated with an increased incidence of Crohn’s disease. Further studies are needed to determine if this association is causal.
Increased sun exposure and higher vitamin D levels may help to protect against the risk of developing multiple sclerosis, a new Australian study suggests.
Multiple sclerosis is an autoimmune disease whose symptoms include loss of balance, slurred speech, muscle spasms, and difficulty walking or moving the legs or arms. Focused on residents living in Australia, the study also echoed prior findings that this disease of the brain and spinal cord strikes with greater frequency among people who live in less sunny regions farther from the equator.
Study co-author Anne-Louise Ponsonby, a professor, epidemiologist and public health physician with the Murdoch Children’s Research Institute at Royal Children’s Hospital in Melbourne, stressed that the exact mechanism by which sun exposure and vitamin D may help protect against a “multi-factorial disease” is not yet clear.
But vitamin D is an important agent that helps modify immune system functioning, she noted, “and laboratory studies have shown higher vitamin D levels can dampen down some of the adverse immune overactivity that occurs in autoimmune diseases such as MS.”
Ponsonby and her colleagues conducted their research with the support of the National Multiple Sclerosis Society of the United States of America, the National Health and Medical Research Council of Australia, the ANZ William Buckland Foundation, and Multiple Sclerosis Research Australia. Their observations are published in the Feb. 8 issue of the journal Neurology.
Exposure to the sun results in increased vitamin D levels, since the body makes vitamin D when it is exposed to the ultraviolet B rays in sunlight.
Although past research (some conducted by the same research team) has uncovered a similar association between sun exposure and MS risk protection, the authors noted that the current finding is the first to examine the impact of sun exposure among individuals who are just experiencing precursor signs of MS, but have not yet actually been diagnosed as having the disease.
This approach, the investigators noted, ensured that the new analysis is focused solely on pre-disease sun exposure patterns, rather than sun exposure routines that might be altered after a diagnosis. (Sunlight exposure has not been shown to benefit MS patients after diagnosis.)
Between 2003 and 2006, the research team looked at 216 patients between the ages of 18 and 59 who had early pre-diagnosis signs of MS. The patients were located in one of four different locations in Australia, with latitudes ranging from 27 degrees South to 43 degrees South.
Almost 400 other study participants without any disease indications were also included in the study for comparative purposes.
All were asked to report how much time they had spent in the sun over weekends and holidays during both summer and wintertime over the course of four different time-frames: between the ages of 6 and 10; 11 and 15; 16 and 20; and during the three years leading up to the study. In addition, skin exams were conducted, and blood samples taken to measure vitamin D levels.
The result: the higher the amount of both past and recent sun exposure (as well as specifically leisure-time exposure), the lower the risk for developing early signs of MS.
Specifically noting that sun exposure ranged from 500 to 6000 kiloujules per meter squared, the authors found that for every additional 1000 kilojoules of exposure, the risk of developing the first signs of MS dropped by 30 percent.
In addition, having a higher vitamin D level was also independently linked to a lower risk for developing MS.
What’s more, those living in the study regions furthest away from the equator faced a 32 percent greater risk for signs of MS than study participants who lived closest to the equator.
And lastly, those with the most signs of skin damage faced a 60 percent lower risk for developing initial indications of MS compared with those with the least amount of skin damage caused by the sun.
While advising that sun exposure “should not be discouraged,” Ponsonby strongly cautioned against the sort of “excessive exposure” that can give rise to a number of adverse health consequences, including possible skin cancer.
Dr. Moses Rodriguez, a professor of neurology and immunology at the Mayo Clinic in Rochester, Minn., agrees that “it’s all about not overdoing it”.
“Dermatologists can get up in arms with these sorts of studies because they’re saying that the amount of sun exposure that you would need to get protection against something like MS would be the amount that would increase your risk for melanoma and skin cancer dramatically,” Rodriguez said.
“But in truth, it appears that your mother’s idea to go out and play in the sun was not necessarily a bad idea,” Rodriguez added. “It’s just that everything has to be tempered. You don’t, for example, want someone to go take 10,000 units of vitamin D. Yes, you need some sun exposure, and you need some vitamin D. Both appear to have some protective effect in terms of MS. But neither is the whole answer, and neither is going to cure MS.”
Nicholas G. LaRocca, vice president of health care delivery and policy research at the National Multiple Sclerosis Society in New York City, praised the study for advancing scientific knowledge about MS.
“I do think this is a very important study,” he said. “It really moves this field forward in terms of refining our understanding of what puts people at risk for developing MS, and what might reduce this risk.”
But like Rodriguez, he also cautioned against “over-interpreting the implications of the current findings.”
“Reading this [study], one might be tempted to say ‘well, I should move to a sunnier climate’ or ‘I should dose myself with tons and tons of vitamin D,'” LaRocca said. “But I don’t think we know enough to really understand what the full and most appropriate implications are. There are many contributions to MS risk, so we will need a lot more research before it becomes clear what’s really going on.”
A new study from France has shown that women who were exposed to a combination of sunlight and dietary vitamin D had up to a 45% reduced risk of contracting breast cancer (BC). The researchers noted that “high” dietary vitamin D by itself did not correlate to a reduced risk of BC, whereas sunlight exposure alone did correlate to a lowered risk.
This research should come as no surprise, since there is a miniscule amount of vitamin D in the typical diet. For instance, the typical 3 ½-oz piece of farmed salmon contains about 175 International Units (IU) of vitamin D; 8 oz. of fortified milk 100 IU; 8 oz. fortified orange juice 100 IU. The amounts typically derived from eggs, oils and margarine is negligible. It is now felt by many experts in the vitamin D field that 4,000-5,000 IU of vitamin D supplementation is necessary for optimal health, so it can be seen that trying to optimize breast health with the paltry 400-500 IU from diet is like trying to color the ocean red with a cup of tomato paste.
Conversely, 20 minutes full-body exposure to summer sunlight at noon can produce as much as 20,000 IU; so this study, showing that sunlight correlates far better to lowered BC risk than does dietary vitamin D, would be expected. However, most people are not actively seeking the sunlight and are not even close to producing the 20,000 IU mentioned. Therefore, in this French BC study, it was probably the combination of both sunlight-produced vitamin D and dietary vitamin D that sufficiently increased blood levels to a threshold that triggered vitamin D’s cancer protection mechanisms, which are numerous.
Other research—a double blind, placebo controlled interventional study—has shown that when vitamin D supplementation is over 1,100 IU daily, there is a profound correlation to a lowered risk (from 60-77%)of all cancers in women.
And as to sunlight per se, Dr. Esther John and colleagues conducted research on the sun-exposure habits of women and correlated those habits to the risk of developing BC. Those women who had the greatest exposure to sunlight were 65% less likely to develop BC.
After the Institute of Medicine (IOM) made their inanely low recommendations for vitamin D supplementation (600 IU daily for all ages), it is good to see that research belying that foolishness continues to surface. We must remember that sunlight exposure is the most natural way to produce vitamin D, and that if supplements are going to be used when sunlight is not available, a minimum of 2,000-4000 IU daily is necessary to optimize blood levels for best health.
 Engel P, Fagherazzi G, Mesrine S, Boutron-Ruault MC, Clavel-Chapelon F. Joint effects of dietary vitamin D and sun exposure on breast cancer risk: results from the French E3N cohort. Cancer Epidemiol Biomarkers Prev 2010 Dec 2. [Epub ahead of print]
 Hollis BW. J Nutr 2005;135:317-22
 Lappe J, Travers-Gustafson D, Davies M, Recker R, Heaney R. Vitamin
D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 2007;85:1586 –91.  John, E. et al. Vitamin D and breast cancer risk: The HANES 1 epidemiologic follow-up study, 1971-1975 to 1992. Cancer Epidemiology Biomarkers and Prevention 1999;8:399-406.
By Richard Gray–
Researchers studying how sun exposure affects the risk of developing melanomas discovered that those who spent between four to five hours in the sun each day over the weekend were less likely to develop tumours.
The findings appear to contradict the commonly-held belief that longer time spent in the sun increases the risk of skin cancer.
Instead, the study shows that while excessive exposure to the sun – and particularly sunburn – can lead to melanomas, regular doses of sun for up to five hours a day at weekends can be protective.
The study comes just days after Andy Flowers, the England Cricket team head coach, underwent surgery to remove a malignant melanoma below his right eye.
Professor Julia Newton Bishop, an epidemiologist who led the research at Leeds University, said it seems regular exposure helps the skin adapt and protect itself against the harmful affects of sunshine. Increased levels of vitamin D made in the skin while exposed to sunlight may also be protective.
Professor Newton Bishop said: “The relationship between the amount of sun we are exposed to and the risk of melanoma is complicated – we have known for a long time that melanomas are something to do with sun exposure and fair skin.
“Our paper suggests that moderate regular sun exposure may actually reduce the risk. We are talking about quite high levels of sun exposure for the protective effect with an average of four to five hours a day at weekends.
“It appears that in moderation, sun exposure can be protective, but it is when you have extreme sun exposure that it becomes a problem. So in the UK sunburn is a potent risk factor because we have a habit of not getting much sun at home and then suddenly exposing our skin when we go abroad.”
Malignant melanoma is the most serious type of skin cancer and around 10,000 people in the UK are diagnosed with the disease each year. The incidence of the disease is rising faster than any other cancer in the UK and has quadrupled since then 1970s. Around 2,000 die each year in this country from skin cancer.
Public health experts blame the rise in skin cancer in the UK on growing use of sun beds and an increase in the number of holidays people take abroad.
Harmful ultraviolet light from the sun is thought to trigger skin cancer by causing damage to the DNA in the skin.
But the new study by Professor Newton Bishop and her colleagues, which is published in the European Journal of Cancer, suggests that regular sun exposure can help the body prevent this damage.
The researchers examined the sun exposure behaviour and skin type of 960 melanoma patients and 687 controls who had not been diagnosed with skin cancer.
After adjusting the results to account for deprivation, they found that participants with fair skin, freckles and blonde or red hair, were most at risk of developing melanomas as where those who had suffered severe sunburn.
But they also found that regular exposure to the sun at weekends of more than five hours had the most significant effect that protected the participants from developing melanoma.
Unfortunately for those with sensitive skin, this protective effect was not seen in people who had red hair and freckles, perhaps due to their tendency to burn far more quickly.
The researchers also measured levels of vitamin D in 1,167 of the participants, who were aged between 18 and 76 years old, and found that those who received regular doses of sun exposure at weekends also had raised levels of vitamin D.
Professor Newton Bishop said: “There is some evidence from other studies that suggests that vitamin D may help to reduce melanoma size and improve prognosis, but it could be that there is some adaptation going on in the skin which reduces the damage from ultraviolet light.
“Melanoma, in the UK, is a cancer of people who work inside who have short bursts of sunshine when they are on holiday. If they are working in offices all week, then when they go sunbathing on holiday, they don’t have the protection that might naturally develop.
“Regardless, people need to take steps to avoid getting sunburnt – particularly at this time of year when the days are shorter and there is much less sunshine around. People who go away for winter sun holidays are particularly at risk.”
If this vitamin isn’t in your medicine cabinet, it probably should be.
By Linda B. White, M.D.
What do the following conditions have in common: osteoporosis, multiple sclerosis, high blood pressure, diabetes and cancer? Give up? Experts suspect that insufficient levels of vitamin D raise your risk of getting these diseases. Unfortunately, most of us probably are vitamin D deficient.
About all I was taught in medical school is that vitamin D keeps bones strong. Recently however, this area of study has exploded as scientists uncover the vitamin’s far-reaching effects. Because it increases calcium levels, vitamin D indirectly fortifies bones and teeth. It also regulates cells all over the body, which explains vitamin D’s disparate roles, such as influencing insulin production and immune function, as well as helping prevent inflammation and cancer.
The scary thing is that vitamin D deficiency appears to be quite common. A recent British study found that 87 percent of volunteers had low blood levels of the vitamin in winter and spring, and 61 percent had low levels in summer and fall. Why the seasonal variation? Our chief source of vitamin D is sunshine.
Why We’re D-ficient
In response to ultraviolet B (UVB) rays in sunlight, our skin transforms a derivative of cholesterol normally found in the skin into vitamin D3 (cholecaliferol). The liver, kidneys and other tissues further activate this molecule. Given that the skin is a veritable vitamin D factory, why is deficiency so rampant? History — ancient and recent — holds the answers.
Humans evolved near the equator and spent days outdoors, allowing the skin to generate ample amounts of this vitamin. About 50,000 years ago, some of our ancestors migrated toward the poles, where winter sunlight isn’t intense enough for vitamin D production. However, their diet of vitamin D-rich fish compensated for the deficit.
But rickets became prevalent in the 18th century during the Industrial Revolution, when people shifted to indoor labor and the skies darkened with pollution. This manifestation of severe vitamin D deficiency causes skeletal deformities, such as bowed or knocked knees and bony knobs along the ribs, known as rachitic rosary. During the 1930s, the decision to add vitamin D to milk nearly eradicated rickets in the United States. But nowadays, kids and adults drink less milk and more juice and sodas, and sadly, rickets is making a comeback in American children according to a study released last year.
Starting about 30 years ago, another cultural shift deepened our vitamin D deficit: public health campaigns to avoid the midday sun, cover up and apply sunscreen. They were justified attempts to save our skins from sun-induced aging and cancer, but now we’re not making enough vitamin D. These days, vitamin D deficiency has become commonplace, even in the tropics. For instance, a sampling of adults in sunny Honolulu showed that half were low in D.
Of course, we can take supplements, but current government recommendations are cautious — 200 IU a day for young adults, 400 for people 51 to 70, and 600 for those over 70. Vitamin D expert Bruce W. Hollis, M.D., of the Medical University of South Carolina, says such doses might be enough to prevent rickets, but aren’t sufficient to fulfill other important functions.
Most of us don’t even meet these inadequate guidelines. A German study found that 80 percent of sampled adults didn’t get recommended amounts, and nearly 60 percent had low blood levels of vitamin D, a statistic that rose to 75 percent in women over 65 years old. Furthermore, those women with low blood levels of vitamin D were more likely to have high blood pressure, cardiovascular disease and type 2 diabetes.
Results of D-ficiency
So what are the dangers of too little vitamin D in your system? A whole host of chronic conditions.
Weak bones and muscles. Rickets was the first disease tied to vitamin D depletion. This severe deficiency during childhood can prevent kids from reaching their potential for full height and peak bone mass. (Bone mass peaks in early adulthood; after that it slowly declines.)
In adults, vitamin D deficiency can lead to osteoporosis (thin, brittle bones) and osteomalacia (rubbery, demineralized bones). The latter causes bone pain, and both elevate the risk of broken bones.
Additionally, vitamin D deficiency causes muscle weakness and discomfort. One study found that patients with aches and weakness were often severely vitamin D deficient. Hollis says he’s hearing from doctors that vitamin D supplementation often resolves these aches and pains, adding, “A lot of ‘fibromyalgia’ is probably D deficiency.”
Weakened muscles increase the risk of falls and fractures — a dangerous combination for the elderly. The research shows that, although the recommended dose of 600 IU a day doesn’t prevent falls and fractures in older adults, doses over 800 IU do. In fact, consuming 700 to 800 IU of vitamin D a day (plus or minus calcium) could prevent a quarter of hip fractures in older people, according to a study published in the Journal of the American Medical Association.
Cancer. Vitamin D deficiency has been linked to several types of cancer, including breast, prostate, colon and melanoma. In fact, for more than 60 years, research has found that people living at higher latitudes with less exposure to sunlight showed an increased risk of cancer mortality. Adequate vitamin D levels seem to protect against some cancers. In a recent study, researchers followed healthy postmenopausal women whom they assigned to take either 1,400 to 1,500 milligrams a day of supplemental calcium plus 1,100 IU a day of vitamin D3, or a placebo for four years. After the first year, vitamin D supplementation led to a 57 percent reduction in cancer.
Cardiovascular disease. In addition to cancer and bone disease, vitamin D may also be healthy for your heart. Vitamin D levels are inversely associated with the risk of high blood pressure and congestive heart failure. Exposing people with high blood pressure to ultraviolet light has been shown to improve the condition.
Asthma. Preliminary studies show that vitamin D also may help alleviate respiratory problems, such as asthma. According to one study published in the American Journal of Clinical Nutrition, children of mothers with lower intakes of vitamin D during pregnancy are more likely to develop asthma.
Autoimmune disorders. Vitamin D reduces inflammation and plays a role in the maturation of the immune system. Deficiency is common in autoimmune diseases where the immune system attacks normal cells, such as type 1 diabetes, rheumatoid arthritis and multiple sclerosis (MS). Emerging research shows that vitamin D may have a preventive effect. One study examined two large groups of women for 10 years and found a reduced risk of MS was associated with vitamin D supplementation. A study of Finnish children taking 2,000 IU a day (10 times the current recommendation) showed they had a decreased risk of developing type l diabetes. In an analysis of the Iowa Women’s Health Study, women consuming higher levels of vitamin D showed a reduced risk for rheumatoid arthritis.
Mental health. Psychiatrist John Cannell, M.D., founder of the nonprofit Vitamin D Council, says that vitamin D may contribute to several emotional disorders. In a study of elderly people, mood and cognitive skills deteriorated with lower levels of D. Cannell points out that seasonal affective disorder (SAD) is a type of depression whose onset follows the waning daylight of autumn and winter. An Australian study found that vitamin D supplements lifted the mood of people with SAD.
How to Get Enough D
Expose yourself. Your skin can tackle much of your vitamin D needs. If you’re young, fair, scantily clad and near the equator, 10 to 15 minutes of peak sunshine produces 20,000 IUs.
However, Hollis says a dark-skinned person requires 10 times that exposure to make an equivalent amount of D. And a 70-year-old person makes only a quarter of the vitamin D that a 20-year-old can produce. During the fall and winter in higher latitudes (above 37 degrees latitude — San Francisco is just above 37 degrees), the levels of UVB fall below the threshold needed for even a fair-skinned person to produce enough vitamin D. Additionally, complete cloud coverage cuts UV energy in half, and shade reduces it by 60 percent.
Sunscreens also block UVB waves, the wavelength that stimulates the skin’s vitamin D production. According to Michael F. Holick, M.D., Ph.D., of the Boston University School of Medicine, a sunblock with SPF 8 reduces the skin’s vitamin D production by 95 percent. “If you wear sunscreen ‘properly,’ you’ll become vitamin D deficient,” he says.
But what about skin cancer? Despite increased sunscreen usage, skin cancer rates have risen. One reason is that, until recently, sunscreens didn’t impede deeply penetrating UVA light, and presumably, our false sense of security led to more time in the sun and an increase in skin cancer.
What should you do? “Be sensible,” Holick advises. “Know your own skin sensitivity.” For instance, if you turn pink after 30 minutes in the summer sun, thenspending five to 10 minutes (in a bathing suit) in the sun should generate plenty of vitamin D. After that, apply sunscreen, cover up and seek shade.
Eat D-licious foods. Only a few foods contain much vitamin D. Sources of vitamin D include cod liver oil (1,360 IU per tablespoon); oily fish such as salmon, sardines and mackerel (about 350 IU per 3.5 ounces); eggs (about 20 IU per yolk); and fortified milk, soy milk and orange juice (98 IU per 8-ounce serving). (We’re testing pasture-raised chicken eggs for vitamin D as part of our 2007 egg testing project. See October/November 2007 for the initial results. — Mother)
Shiitake mushrooms can be an exceptional source of vitamin D, as noted in research published in Paul Stamets’ book, Mycelium Running. Shiitake mushrooms grown and dried indoors have only 110 IU of vitamin D per 100 grams. But when the shiitakes were dried in the sun, the vitamin D content rose to 21,400 IUs per 100 grams. Even more surprising, when the mushrooms were dried with their gills facing up toward the sun, their content rose to 46,000 IU!
Take supplemental D. Most North Americans can’t maintain healthy blood levels of D from sunlight and good diet. Therefore, many experts recommend 800 to 1,000 IU a day — several times the government guidelines of 200 to 600 IU.
The exact amount depends upon several things. If you’re dark-skinned or spend little time outdoors, you’ll obviously need more than a Caucasian lifeguard. And if you’re already deficient in vitamin D, you’ll need hefty doses just to get your blood levels up to normal.
If you’re pregnant or nursing, you’ll also need more. Hollis and colleagues are currently researching the effects of different vitamin D doses in pregnant women of various races. Until the results of that trial are finalized, he can’t recommend more than 2,000 IU per day.
When asked how much vitamin D they normally take, Hollis says he takes 4,000 IU a day, while Holick says each member of his family takes 1,000 IU of D3 a day. Holick also spends reasonable amounts of time outdoors.
Be aware that many supplements provide vitamin D as ergocalciferol (vitamin D2), rather than cholecalciferol (vitamin D3). D3 is the form naturally occurring in our bodies and is more effective.
No one really knows how much vitamin D might be too much; however, toxicity is exceedingly rare. The Food and Nutrition Board sets the upper level for daily dietary intake at 2,000 IU, though Hollis thinks that’s not enough to maintain health at northern latitudes. Accumulated research demonstrates 10,000 IU of vitamin D3 to be a more realistic upper limit.
Who’s at Risk?
The only way to measure vitamin D blood levels is to check a form of vitamin D called 25-hydroxyvitamin D. Doctors don’t routinely perform this test, and Holick thinks universal screening would be too expensive. If you’re at risk for, or already have symptoms of, deficiency, then you might want the blood test.
Just who’s at risk? Research shows the following populations face greater risk of vitamin D deficiency:
Dark-skinned people. Melanin darkens skin and absorbs UV light, which protects against sun damage and limits vitamin D production. Holick’s research shows that 80 percent of African-Americans studied in Boston over age 65 were vitamin D deficient — at the end of summer!
Northerners. People who live at higher latitudes where winters are long and dark run a higher risk of vitamin D deficiency. Holick notes that even fair-skinned people living above 37 degrees latitude make little vitamin D during the winter.
Older adults. The skin production of vitamin D and its activation in the kidneys declines with age. Further, the elderly typically spend more time indoors. Vitamin D deficiency in this age group contributes to osteoporosis and falls.
Breast-fed infants. Research in Iowa by Hollis and colleagues found that vitamin D deficiency, including severe deficiency, was common among breast-fed infants without vitamin D supplementation. Vitamin D deficiency in nursing mothers is the reason breast milk is D deficient. Unfortunately, early deficiency can have lifelong consequences.
People with intestinal disorders. Disorders that interfere with fat absorption include celiac disease, Crohn’s disease, pancreatic insufficiency, liver disease or cystic fibrosis. Fat-soluble vitamins such as D are absorbed from the intestine with dietary fat, so people with low ability to absorb fat may need vitamin D supplements.
Sun avoiders. People who cover up for religious, cultural or health reasons also run the risk of deficiency. Clothing blocks UVB waves, interfering with or preventing the skin’s formation of vitamin D.
The obese. In a British study, obese people were twice as likely as those of normal weight to be low in vitamin D. Hollis explains it’s because fat sponges up vitamin D and stores it, but doesn’t release it.