Your Body Is Designed to Optimize Health Effects of Sun Exposure

While you certainly need to avoid the skin damage associated with sunburn, sun exposure is required for optimal health, and your skin type plays a major role in how much UVB exposure you need and can safely tolerate. Darker-skinned people not only need more sun exposure to produce sufficient amounts of vitamin D, they're also more protected from skin cancer due to their skin pigmentation. Yet this important reality is simply ignored by dermatologists, resulting in most African Americans being at a radically increased risk of cancers and heart disease from vitamin D deficiency.

As noted in a previous article by Nautilus: How the sun affects you depends on your complexion, the shade of which is determined by melanin ... The anti-oxidizing molecule is so versatile at protecting and repairing DNA from UV solar radiation that creatures from humans to fungi deploy it ... [T]he melanin sits atop cellular DNA like tiny umbrellas pointed ... out to shield from incoming rays ... the same ultraviolet wavelengths in the 290 to 400 nanometers range that trigger melanin production also spark vitamin D creation. You cannot make one without the other. Humans evolved to produce two kinds of melanin ... The MC1R gene determines the type of melanin the body produces. In the mid-zone such as the Mediterranean region, people ... produce eumelanin, the pigment responsible for brown or black hair and for dark skin that tans easily ... in far northern Europe, humans paled, adapting to lower light ... with a different type of melanin, called pheomelanin, associated with fair skin and blonde and red hair with minimal protective value, but allowing more UV to penetrate to make vitamin D.

Sun Avoidance Raises Risk of Internal Cancers

Dermatology is focused on one primary outcome—avoiding skin damage and skin cancer. But by focusing on just one side of the UV exposure issue, they're actually promoting a lifestyle that may raise your risk of other lethal cancers and chronic diseases. Not only have higher vitamin D levels been shown to offer significant protection against a number of internal cancers, there's also evidence showing higher levels offer protection against melanoma. In fact, higher rates of melanoma are found among those who have low vitamin D levels; among indoor occupations; and in areas of the body that rarely or never see the light of day. In short, the vitamin D your body produces in response to UVB radiation is protective against skin cancer. As noted in The Lancet: Paradoxically, outdoor workers have a decreased risk of melanoma compared with indoor workers, suggesting that chronic sunlight exposure can have a protective effect.

Even more importantly, vitamin D has been shown to significantly reduce internal cancers, along with chronic diseases such as heart disease, which kill far more people than melanoma does. Breast and prostate cancers are just two examples where low vitamin D renders you more vulnerable to more aggressive forms of the disease. Recent research has also found that low vitamin D levels are associated with more severe peripheral neuropathy in cancer patients.

Reporting on recent research linking low vitamin D levels to an increased risk for aggressive breast cancer, Medical Daily writes: The researchers linked vitamin D levels to the ID1 gene, which at high levels of expression is associated with breast cancer tumor growth. Past studies have shown that vitamin D is linked to inhibiting the expression of this gene, and that low vitamin D levels have been associated with more aggressive tumors.

Public Health Messages Should Be Based on All-Cause Mortality Reduction

According to a scientific review by Dr. Richard Weller, a dermatologist, sun exposure also has cardiovascular benefits independent of vitamin D. One of the key messages presented in his paper states that: All-cause mortality should be the primary determinant of public health messages. Sunlight is a risk factor for skin cancer, but sun avoidance may carry more of a cost than benefit for overall good health. In short, if you're concerned about mortality, and not just mortality from one disease, the scales are decidedly tipped toward sun exposure being of tremendous benefit—despite a minor risk of melanoma, should you accidentally end up getting burned one or more times in your life. Unfortunately, the field of dermatology refuses to take the entire picture into account when making its recommendations about UV exposure.

UV Light Is Essential for Human Health

We are not nocturnal beings, and while high intermittent and/or overexposure to UV light can cause potentially serious harm, it's a manageable risk provided you use common sense and pay careful attention to some basic elements. The advice to completely avoid UV light is quite dangerous, and one that extends far beyond just vitamin D deficiency, as sunlight has health benefits that go beyond vitamin D production.

To mitigate the risks of UV exposure while maximizing the benefits, here are some factors to consider: Our skin pigmentations are linked to ancestral latitudinal proximities that optimized our ancestors' skin for sun exposure. The further from the equator our ancestors lived, the lighter their skin, allowing them to biologically maximize the limited availability of the sun, and UV light specifically. Remember: Your body produces vitamin D through exposure to UVB light. For those living in northern latitudes, this may only be an option for a few short months each year.

• If you accept the essential nature of UV light, then you can conclude that safe exposure to sunshine is possible by understanding your skin type, the UV strength at the time of exposure, and your duration of exposure. My advice has been clear: Always avoid sunburn. Once your skin develops the slightest tint of pink, cover up with clothing to avoid further exposure.
  
  
• Pay close attention to your vitamin D levels. Ideally, get your vitamin D tested during the peak of summer and at the end of winter to help guide your UV exposure and vitamin D supplementation.
  
  
• UVB exposure on bare skin is required for your body to produce vitamin D. The more skin that is exposed when UVB is available, the less time you need. Since few foods contain any significant amount of vitamin D, and your body certainly was not designed to get its vitamin D from supplements, which are a modern invention, the only rational conclusion is that sun exposure is the ideal way to raise your vitamin D level.

UV light has benefits beyond vitamin D. For more information, see the TED Talk above, or read through "Sunlight Has Cardiovascular Benefits Independently of Vitamin D," produced by Richard B. Weller Medical Research Council Centre for Inflammation Research, University of Edinburgh.

The Role of Vitamin D in Disease Prevention

A growing body of evidence shows that vitamin D plays a crucial role in disease prevention and maintaining optimal health. There are about 30,000 genes in your body, and vitamin D affects nearly 3,000 of them, as well as vitamin D receptors located throughout your body. According to one large-scale study, optimal Vitamin D levels can slash your risk of cancer by as much as 60 percent. Keeping your levels optimized can help prevent at least 16 different types of cancer, including pancreatic, lung, ovarian, prostate, and skin cancers. Is it any wonder then that no matter what disease or condition is investigated, vitamin D appears to play a crucial role?

Dr. Joseph Mercola was trained by the conventional model. In his first years of private practice, he treated many symptoms with prescription drugs and was actually a paid speaker for the drug companies. But as he began to experience the failures of this model in his practice, he embraced natural medicine and has had an opportunity over the last thirty years to apply these time-tested approaches successfully with thousands of patients in his clinic. Over 16 years ago he founded Mercola.com to share his experiences with others. The site is the most visited natural health site in the world for the last seven years with nearly two million subscribers. He’s also written two NY Times bestselling books, and has had frequent appearances on national media.