Dr. Mercola March 15 2008 111,137 views
Researchers have found that the production of previtamin D3 in your skin varies depending on several factors, which include skin type, weather conditions, and sunscreen use.
During the winter at latitudes above 35 degrees, there is minimal previtamin D3 production in the skin. Darker skin pigmentation, application of sunscreen, aging and clothing can also have a dramatic effect on previtamin D3 production.
However, at the other end of the scale, excessive exposure to sunlight does not result in vitamin D overdose, because previtamin D3 and vitamin D3 are photolyzed to biologically inert chemicals before they can build up to dangerous levels.
I believe the evidence is quite clear; your likelihood of developing deadly skin cancer from sun exposure is nowhere near as high as you have been led to believe in the past. The benefits of normalizing your vitamin D levels FAR outweigh any risk you may have from optimal sun exposure.
So I’m glad to see that there are more scientific arguments promoting healthy sun exposure, and the focus is finally shifting toward making sure you’re getting the right amount of exposure based on your individual variables.
Why Anti-Tanning Propaganda Takes Lives
In a groundbreaking study, researchers from the Moore’s Cancer Center at the University of California, San Diego (UCSD) concluded that increasing the intake of vitamin D3 throughout the world could easily prevent diseases – including 16 types of cancer -- that would otherwise claim close to 1 million lives each year worldwide.
The truth is, this pervasive and persistent anti-tanning campaign has not done you any favors. It has enriched sun lotion manufacturers, but most likely caused more disease than it prevented.
The only risks of UVB come from overexposure. This can be greatly minimized by avoiding sunburn, and eating a healthy diet, rich in antioxidants. The recommendation to never go out in the sun without wearing sunscreen, however, is simply misguided advice. Slathering on sunscreen will effectively shield you from the sun’s inherent health benefits, so your body will not synthesize vitamin D properly.
It’s also important to remember that you can develop sun damage even with sunscreen. Sunscreens don’t stop the damage from occurring, they simply stops the burn. But damage can still occur on a cellular level.
Even worse, most sunscreens contain toxic chemicals that absorb through your skin, adding to your toxic load and even increasing your cancer risk.
Individual Variables That Affect Your Vitamin D Levels
It’s important to bear in mind that everyone responds differently to sunlight, depending on factors such as:
A person with dark skin, for example, may need as much as ten times more sun exposure to produce the same amount of vitamin D as a person with pale skin.
You will need to carefully determine your own sunlight needs and tolerances, and learn what kind of exposure you need to tan without burning. Let’s look at how a few of these individual variables can affect your vitamin D levels, and the amount of sun exposure you might need.
How Antioxidants and Vitamins Can Help Prevent Sunburn
You may not realize that the amount of antioxidants that you have in your skin plays a major role in your development of sunburn. The more antioxidants you take in, the lower your risk of sunburn. Foods containing effective antioxidants to boost your “internal sunscreen” include whole fresh vegetables and fruits such as:
Vitamins A and C are also vital as your cells use these vitamins to regulate both light absorption and protection against overexposure. According to nutritional researcher Krispin Sullivan, Scandinavians and other very light skinned people can benefit tremendously from making sure they are sufficient in these vitamins as it will protect their skin from burning too quickly.
Safe Tanning Guidelines
If your skin is unused to the sun, it is important to build up your tolerance regularly and gradually. It’s good to start early in the year, in the spring and early summer. This will prepare your skin for the stronger sunlight later in the year.
At the beginning of the season, go out gradually and limit your exposure to perhaps as little as 10 minutes a day. Progressively increase your time in the sun so that in a few weeks, you will be able to have normal sun exposure with little risk of skin cancer.
Time of Day -- Early morning is, for similar reasons, the best time to sunbathe if you have not already built up a base tan, because you’re less likely to burn in the mild morning sun than later in the day. In addition, it’s best to sunbathe when the temperature is below 64 degrees Fahrenheit (18 degrees Celsius), so that you don’t overheat. Regular Intervals -- Regular sunbathing is extremely important; you can’t cram all of your sun exposure into a two or three week vacation period and expect to experience the benefits. It’s also important to treat your tanning as a medicine and control the dosage; frequent, short periods of exposure are best. You don’t want to overindulge or skip too many days. Regular exposure actually protects against skin cancer, but intermittent overexposure can increase the danger. Show Some Skin -- A common myth is that occasional exposure of the face and hands to sunlight is "sufficient" for vitamin D nutrition. For most of us, this is an absolutely inadequate exposure to move vitamin levels to the healthy range of 45-55 ng/ml. For optimal benefit, strive to have at least 40 percent of your skin uncovered. Optimal Exposure Time -- In Caucasian skin, equilibrium occurs within 20 minutes of ultraviolet exposure. It can take 3 to 6 times longer for darkly pigmented skin to reach the equilibrium concentration of skin vitamin D. So, bearing in mind that you need to gradually increase your time, starting in the spring, you should be aiming towards exposing large areas of your skin to the sun, anywhere from 20 minutes to 2 hours at a time, depending on your skin type and environmental factors. A light-skinned person fairly far from the equator (such as in the UK or the northern U.S.) needs at least three of these 20 minute sessions per week, in bright midday sunlight and with few clothes. Longer will be needed if sunbathing occurs at off-peak times for ultraviolet light (before 12 PM or after 3 PM) or at the beginning or end of the summer (April or September). A dark-skinned person, of course, should be outside significantly longer. Using Your Skin as a Guide-- If you have light-colored skin, you can use the color of your skin to tell you when you’ve had enough sun and it’s time to get in the shade (or cover up using a long-sleeved shirt, pants, and a hat). Stay out just long enough so that your skin turns the very lightest shade of pink. Remember that continuing UV exposure beyond the minimal dose required to produce skin redness will not increase your vitamin D production any further.
Time of Day -- Early morning is, for similar reasons, the best time to sunbathe if you have not already built up a base tan, because you’re less likely to burn in the mild morning sun than later in the day. In addition, it’s best to sunbathe when the temperature is below 64 degrees Fahrenheit (18 degrees Celsius), so that you don’t overheat.
Regular Intervals -- Regular sunbathing is extremely important; you can’t cram all of your sun exposure into a two or three week vacation period and expect to experience the benefits.
It’s also important to treat your tanning as a medicine and control the dosage; frequent, short periods of exposure are best. You don’t want to overindulge or skip too many days. Regular exposure actually protects against skin cancer, but intermittent overexposure can increase the danger.
Show Some Skin -- A common myth is that occasional exposure of the face and hands to sunlight is "sufficient" for vitamin D nutrition. For most of us, this is an absolutely inadequate exposure to move vitamin levels to the healthy range of 45-55 ng/ml. For optimal benefit, strive to have at least 40 percent of your skin uncovered.
Optimal Exposure Time -- In Caucasian skin, equilibrium occurs within 20 minutes of ultraviolet exposure. It can take 3 to 6 times longer for darkly pigmented skin to reach the equilibrium concentration of skin vitamin D.
So, bearing in mind that you need to gradually increase your time, starting in the spring, you should be aiming towards exposing large areas of your skin to the sun, anywhere from 20 minutes to 2 hours at a time, depending on your skin type and environmental factors.
A light-skinned person fairly far from the equator (such as in the UK or the northern U.S.) needs at least three of these 20 minute sessions per week, in bright midday sunlight and with few clothes. Longer will be needed if sunbathing occurs at off-peak times for ultraviolet light (before 12 PM or after 3 PM) or at the beginning or end of the summer (April or September).
A dark-skinned person, of course, should be outside significantly longer.
Using Your Skin as a Guide-- If you have light-colored skin, you can use the color of your skin to tell you when you’ve had enough sun and it’s time to get in the shade (or cover up using a long-sleeved shirt, pants, and a hat). Stay out just long enough so that your skin turns the very lightest shade of pink.
Remember that continuing UV exposure beyond the minimal dose required to produce skin redness will not increase your vitamin D production any further.
Please Remember to Check Your Vitamin D Levels
Last but not least, it’s always a good idea to get your vitamin D levels checked regularly, and adjust your sun exposure accordingly to maintain your optimal vitamin D level. For more information about the correct test to get and your optimal -- as opposed to “normal” – levels, please review my previous article, Scientists Admit -- Sun Exposure Benefits Outweigh Risks that I wrote earlier this year.
Additionally, my new book, Dark Deception, which is coming out later this spring, will help to clear up the confusion about sun exposure once and for all.
In Canada it's 80- 120nmol/L.
Mine is 92nmol/L and I've been told that researchers are finding 91nmol/L the level that is helping to prevent cancer.
I take Ddrops which Dr. Reinhold Vieth uses in his clinial trials in Canada.
Careful though the-powers-that-be will look for a way to charge us for sunshine. Where we live is greatly important to this equation.
Celticblobby:
When Islander says altitudes, he most likely is referring to the altitude or height of the ground you live on, i.e. mountains are high altitudes and receive more direct sunlight.
I would add one thing to this debate that seems to get lost. I have read that sunlight striking the optic nerve is the mechanism that releases melanocytes that are responsible for the production of melanin. Melanin is the stuff that builds up our defenses against the harmful cancer causing effect of the sun. If you wear sunglasses you are muting this effect. This might be one of the things that could help explain why the sun can cause cancer today and is unlikely to have done this to our ancestors.
Wow - I've read some or a lot on most of the info in this post, but never this. Thank you. Do you have info to back this up? Or, I would hope Dr. Mercola would followup. Why I find this so interesting is that just when I was becoming conscious of conrolling my own health, (many moons ago) I frequented a healthfood store in CA. The elderly woman who owned it surprised me with 3 comments - that much later, I have now found are true, or possibly true. First, when we all started talking about cholesterol, most doctors gave their patients one number and if it was over that it was BAD. She said "bull" (and something else - teehee) you have to consider the good and the bad and that there was more involved than just "high cholesterol". She later told me one very hot day, as she watched a couple of kids walking by with sunglasses on that "They are ruinnnnnng there health - sun glasses are dangerous!!!!" She later when the carb craze started said (and, I will say she was full blood Italian) that if you eat pasta, just make sure it's made with Seminola flour and you'll be fine!! This one I've never heard of since....
anyone out there have info?????
Another interesting addition: your eyes need UV rays in order for the cells to divide and reproduce. No reproducing leads to things like bifocals early on. Think about it, how many times do you see eyeglasses without UV protection? Even our windhields have the UV protective glass. Read an article on ppnf.org about this issue.
mrose: Regarding semolina, the late gerontologist Roy L. Walford stated in one of his books (I think "Maximum Life Span"), to eat only whole-grain pasta, NOT semolina. I don't know what processing is done to whole grain to make semolina (perhaps removes some of the fiber along with some of the nutrients), but his advice made intuitive sense and I've been following it. He also wrote, "Beyond the 120-Year Diet: How to Double Your Vital Years" and "The Anti-Aging Plan..."
I posted this once before. The sunglasses info is from a book called Survival of the Sickest. In a chapter entitled The Cholesterol Also Rises on pages 53-54
"As everybody knows, skin color changes, to some extent, in response to sun exposure. The trigger for that response is the pituitary gland. Under natural circumstances, almost as soon as you are exposed to the sun, your pituitary gland produces hormones that act as boosters for your melanocytes, and your melanocytes start producing melanin in overdrive. Unfortunately, it's very easy to disrupt that process. The pituitary gland gets it's information from the optic nerve - when the optic nerve senses sunlight, it signals the pituitary gland to kick-start the melanocytes. Guess what happens when you're wearing sunglasses? Much less sunlight reaches the optic nerve, much less warning is sent to the pituitary gland, much less melanocyte-stimulating hormone is released, much less melanin is produced - much more sunburn results. If you're reading this on the beach with your Ray-Bans on, do your skin a favor - take them off."
I'm glad to hear this. I've always been the one to purchase sunglasses and lose them three days later only to go on to endure the summer without any at all. I've always felt a little bad about not "taking care" of my eyes, and being in my early twenties, I've been given a hard time by friends on occasion. I'm relieved to know that I now have a good reason to never go out and purchase another pair of sunglasses again.
I'm afraid I have become somewhat of a scandal. Even in winter, I go out in a tank top when I can. I tell everyone my doctor prescribes sunshine for my health, but because their doctors don't say things like that and because everyone likes a juicy story, apparently the word is I'm looking for "adventure." I may have to learn karate in case any of the rogues in town try to take me up on it. Gracious!