By Dr. Mercola
Over the past 40+ years, dermatologists have promoted the idea that you should never be exposed to direct sunlight because it will damage your skin and cause skin cancer.
What they fail to acknowledge and appreciate is that when you're exposed to sunlight, many important biological processes occur in your skin, not just vitamin D production.
This is separate from swallowing oral vitamin D, which is an important but, according to many experts, clearly inferior alternative. While it will improve your vitamin D status, you forgo the many benefits sunlight offers aside from vitamin D production.
Weighing the Risks and Benefits of Sun Exposure
Unfortunately, the entire focus of most dermatologists is preventing skin damage, which means ignoring the other side—the benefits—of the sun exposure equation.
This includes heightened protection against a number of internal cancers and other chronic diseases, including heart disease, which kills far more people than melanoma does.
Ironically, recent research shows that vitamin D also improves survival outcomes for melanoma patients.2,3 It's also important for cognitive health, immune function, healthy pregnancy and infant development, and strong, healthy bones, just to name a few.4
As noted in a recent news report:5
"Fifteen to 20 minutes in sunlight a day helps your body produce the vitamin D it needs to absorb calcium and promote bone growth and keep the heart healthy. But sunscreen - important to protect against skin cancer — reduces the body's ability to manufacture the vitamin.
Doctors can be torn on recommending time in the sun when too much and too little both have consequences."
Sun Avoidance Decreases Melanoma Risk But Increases All-Cause Mortality
A recent study6,7 driving home these benefits was completed in Sweden. More than 25,500 Swedish women between the ages of 25 and 64 were followed for 20 years. Detailed information about sun exposure habits and confounding factors were obtained and analyzed in a "competing risk" scenario.
Overall, women who got regular sun exposure had a lower all-cause mortality risk—likely due to their increased vitamin D levels.
Women with active sun exposure habits ended up having a lower risk of cardiovascular disease and non-cancer death compared to those who avoided the sun. Of particular note:
"Nonsmokers who avoided sun exposure had a life expectancy similar to smokers in the highest sun exposure group, indicating that avoidance of sun exposure is a risk factor for death of a similar magnitude as smoking.
Compared to the highest sun exposure group, life expectancy of avoiders of sun exposure was reduced by 0.6–2.1 years." [Emphasis mine]
Other Research That Puts Melanoma Risk Into Perspective
Previous research has shown that when sunlight strikes your skin, nitric oxide is released into your bloodstream8 and nitric oxide is a powerful blood pressure lowering compound.
This has led researchers to conclude that sun exposure may prolong your life by significantly cutting your heart attack/stroke risk. One 2013 study9 mentions an absolutely stunning statistic.
For every one skin cancer death in northern Europe, between 60 and 100 people die from stroke or heart disease, related to hypertension. Knowing your risk of dying from heart disease or stroke is 80 times greater on average than from skin cancer really puts it in perspective.10
While higher vitamin D levels correlate with lower rates of cardiovascular disease, oral vitamin D supplements do not appear to benefit blood pressure, and the fact that supplements do not increase nitric oxide may be the reason for this.
According to researcher Richard Weller:
"We suspect that the benefits to heart health of sunlight 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 sunlight."
Lack of Sun Exposure May Be Driving Tuberculosis Epidemic
Cardiovascular disease is not the only disease influenced by sun exposure that kills far more people than melanoma. Did you know that some 4,100 people die from tuberculosis (TB) EVERY day around the globe?11
In 2014, there were 1.5 million TB-related deaths worldwide. Compare that to the 438,000 who died from malaria—a well-known global infectious disease—and the 55,100 who die from melanoma each year (worldwide).
Tellingly, TB rates are particularly high among miners and prisoners, two populations exposed to far less sunlight than the average person. African miners have the highest incidence of TB in the world.12
One of the reasons why TB isn't on everyone's radar is because it's been around for hundreds of years, and the disease (spread by airborne bacteria that settle in the lungs and result in long-term infections) doesn't evoke the same drama as HIV or Ebola.
The reason it should be on everyone's radar is because it's now the No. 1 infectious disease out there.
No one is safe from it, and with rising antibiotic-resistance, it may just be a matter of time before TB can no longer be treated with antibiotics, in which case the death toll is likely to skyrocket even further—especially if sun avoidance continues to be aggressively promoted.
Tuberculosis—A Global Health Threat That Could Be Counteracted With Sun Exposure
What people seem to have forgotten is that, traditionally, TB was treated with sunlight, and it's a well-established fact that UV light is anti-infective. For example, a 2009 study13,14 found that UV light could reduce the spread of tuberculosis in hospital wards and waiting rooms by 70 percent.
Other studies have similarly concluded that UV light and blue light has potent antibiotic activity. It can even be used to disinfect water15 in lieu of harsher disinfection chemicals like chlorine. In 2012, researchers announced UV light helps kill 90 percent of drug-resistant bacteria in hospital rooms.16
Vitamin D from sun exposure also increases your body's production of naturally occurring antimicrobial peptides that destroy the cell walls of viruses and bacteria. Sun exposure also increases blood levels of germ-destroying lymphocytes (white blood cells).
Auguste Rollier began using sunlight therapy to treat TB in Switzerland in 1903. The treatment was so successful that over the course of the next 40 years, his methods were adopted by hospitals worldwide, including in the United States.
Of the 2,167 patients who were under his care for tuberculosis following World War II, 1,746 completely recovered their health, an astonishing number for the time, with the only failures being those who were already in the most advanced stage of the disease.
Vitamin D Supplements May Also Help Combat Drug Resistant TB
Studies have shown that metabolizing vitamin D can restrict the growth of tuberculosis within cells.17 In one study, Indonesian scientists found that treating tuberculosis patients with 10,000 units of vitamin D daily (instead of the much smaller amount usually advocated by conventional medicine) led to a cure rate of 100 percent — everyone in the study.18 Quite impressive indeed!
Other recent research19 suggests vitamin D may enhance your body's ability to kill drug-resistant TB—an effect thought to be related to the fact that vitamin D helps decrease inflammation in your body. Tuberculosis is not the only disease documented to be influenced by vitamin D and UV radiation. Sunlight has also been shown to be effective against anthrax, cholera, E. coli, dysentery, influenza, staphylococcus, streptococcus, and other infectious illnesses.
The time honored tradition of hanging your clothes outside to dry even works as a natural germicidal to kill off potential pathogens. This is especially important for your bed clothes, and if you have the ability, I highly recommend hanging your laundry out to dry when the weather permits.
Breaking News—Sun Avoidance Is Misguided
While the American Academy of Dermatology, the Skin Cancer Foundation, and the U.S. Surgeon General20,21 have all declared UV radiation harmful and said sun exposure should be avoided altogether, Some individuals are bucking the status quo by recommending sun exposure. In a March 10, 2016 "Positive Choice" newsletter covering general wellness, it states:22
"It is true that too much sun exposure, and especially sun burns, contribute to skin cancer. But the message to avoid the sun altogether may be misguided. Our increasing knowledge about vitamin D, the sun, and how they affect our immune system has us re-thinking the recommendation to avoid the sun completely.
Our ancestors were outdoors far more often than indoors. How could we have evolved and survived as a species if we were that vulnerable to something humans have been constantly exposed to for their entire existence? Like all living things, we need sunshine.
Much as plants harness the sun's rays through photosynthesis, our bodies use the UVB radiation in sunshine to stimulate increased production of vitamin D. Vitamin D is needed to build bones, quell inflammation, bolster the immune system, and protect against disease."
Sun Exposure is Vital
It goes on to note that vitamin D deficiency is widespread—as many as 70 percent of American children may have insufficient levels—and lists a number of adverse health effects thereof, including those listed below. It also notes that "infants that are born from vitamin D deficient mothers and remain vitamin D deficient for the first several months after birth have a greater risk of developing obesity and chronic diseases later in life."
✓ Heart disease
✓ High blood pressure
✓ Multiple sclerosis
✓ Autoimmune disease
As if taken straight out of my own newsletter, it states: "Most people have heard of the studies that connect sun exposure to skin cancer. But there are many studies that suggest sun exposure (and maximizing vitamin D levels) plays a role in decreasing risks of at least 16 different types of cancer including lung, pancreatic, breast, ovarian, prostate, and colon cancers.
Without question sun exposure and the vitamin D we make when in the sun is vital to health. But how much do we need? ... Some experts recommend blood serum levels as high as 75 ng/ml ... The Institute of Health recommends blood serum levels at 40 ng/ml, the amount that meets the needs of most people. Using either value, many Americans are deficient in vitamin D ...
For healthy people, moderate sun exposure (2 to 4 times a week for 15 to 30 minutes) is not a problem. Just as important as not avoiding the sun all together, it is important to not just bake away. Rather follow healthy sunbathing tips...
The benefits we receive from the sun have focused primarily on its ability to stimulate vitamin D production, but there may be other benefits we get from the sun that are not yet well understood. Even if you supplement with vitamin D, it's still a good idea to get some sunshine as well."
Healthy Sunbathing Tips
The "healthy sunbathing tips" also follow the same guidelines I've promoted for many years, including:23
- Only get sensible sun exposure and always avoid sunburn.
- Build up your tolerance by starting early in the spring, and gradually increase the time you spend in the sun to avoid getting burned. Once your tolerance has been built up, aim for 15 to 30 minutes of unprotected exposure two to four times per week, around mid-day, to maximize vitamin D production
- Expose as much skin as you can, not just your arms and face
- Avoid burning
- Boost your "internal sunscreen" by eating antioxidant rich foods and healthy fats. As noted "These foods strengthen skin cells, helping to protect them from sun damage. On a regular basis eating several servings of vegetables and fruits such as blueberries, raspberries ... and supplementing with green powdered mixes (wheat grass, barley grass, seaweed powders, etc.) and fish oils are great options when going into the sun."
As a general rule, the best time to get sun exposure to optimize your vitamin D levels is close to solar noon, which is 1 p.m. in those states that foolishly use Daylight Saving Time. So, between 10 a.m. and 3 p.m. from March through October. November through February, you will not be making vitamin D if you live north of Atlanta, Georgia, and even at southern latitudes, you'll only be making 10 to 20 percent of your summertime norm.
During winter months, your alternatives are to use a tanning bed, or take an oral vitamin D3 supplement. If you opt for a supplement, remember that you also need to increase your vitamin K2 intake. I strongly recommend getting your vitamin D level tested at least once or twice a year, say during the winter and summer, to make sure your chosen strategy is providing you with enough vitamin D. Ideally, you'll want your level to be between 40 and 60 ng/ml year-round.
Sun Exposure for Vitamin D and Beyond
If you look at the spectrum of sunlight that reaches the Earth's surface, UVB radiation is responsible for making vitamin D. But UVA, while being responsible for most of the skin damage also helps modulate your immune system, and UVA and UVB in combination improves beta-endorphin production in your skin, which makes you feel good.
Sun exposure on bare skin also produces nitric oxide and carbon monoxide that cause vascular relaxation, improves wound healing, and helps fight infections among other biologic processes. The carbon monoxide your hemoglobin molecules release in response to UV radiation also acts as a neurotransmitter, and has beneficial effects on your nervous system. Like nitric oxide, it causes relaxation, and has anti-inflammatory activity.
The blue wavelength of sunlight is particularly important for regulating your circadian rhythm and suppressing melatonin levels; it helps improve your mood, and reduces depressive symptoms. Light therapy has been shown to be effective not only against seasonal affective disorder (SAD) but also non-seasonal major depression. So all in all, sun exposure provides a wealth of health benefits over and beyond mere vitamin D production, although that's certainly a big part of it.
Clearly, when you weigh the risks and benefits, sensible sun exposure does more good than harm, and I'm quite pleased to see a push against the misguided advice to stay out of the sun, just to lower your risk of melanoma. At the end of the day, your risk o f dying from melanoma is FAR lower than your risk of dying from other diseases associated with sun avoidance, such as TB and heart disease for example.