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Facts You Need to Know About Sunlight and Skin Cancer


Noted expert Dr. John J. Cannell discusses the powerful benefits of vitamin D. Safe sun exposure may be the best thing for your skin, no matter what you may have heard! 

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Dr. Mercola''s Comments Dr. Mercola's Comments:

In this video, Dr. John Cannell -- one of the leading authorities on vitamin D and founder and Executive Director of the Vitamin D Council -- sheds additional light on what several studies have already confirmed: that appropriate sun exposure actually helps prevent skin cancer. In fact, melanoma occurrence has been found to decrease with greater sun exposure, and can be increased by sunscreens.

One such study discovered that melanoma patients with higher levels of sun exposure were less likely to die than other melanoma patients, and patients who already had melanoma and got a lot of sun exposure were prone to a less aggressive tumor type.

How can this be? Experts are still recommending caution when going out in the sun, and the science still points to the fact that skin cancer is caused by sun exposure. 

As Dr. Cannell explains, the sun does increase genetic damage in your skin and can cause skin cancer, but nature has designed a clever system to obviate this risk. And by staying out of the sun entirely, you avoid the system nature created to help prevent skin cancer.  

As you probably know by now, vitamin D is formed in your skin from exposure to sunlight. The vitamin D then goes directly to the genes in your skin where it helps prevent the types of abnormalities that ultraviolet light causes. Hence, when you avoid the sun entirely, or slather on sun block whenever you go out, your skin is not making any vitamin D, and you’re left without this built-in cancer protection.

But you’re not only raising your risk of skin cancer by shunning the sun.

Optimizing your vitamin D levels can help you to prevent as many as 16 different types of cancer including pancreatic, lung, breast, ovarian, prostate, and colon cancers. And vitamin D does not have just a slight impact on your cancer risk. It can cut your risk by as much as 60 percent!

Its protective effect against cancer works in several ways, including: 

  • Increasing the self-destruction of mutated cells (which, if allowed to replicate, could lead to cancer)
  • Reducing the spread and reproduction of cancer cells
  • Causing cells to become differentiated (cancer cells often lack differentiation)
  • Reducing the growth of new blood vessels from pre-existing ones, which is a step in the transition of dormant tumors turning cancerous 

To Prevent Skin Damage You Have to Protect Against the Most Damaging Rays

Ultraviolet light from the sun comes in two main wavelengths – UVA and UVB.  The difference between them is part of the equation, so it’s important for you to understand the difference between the two.

UVB can be considered the ‘good guy’ that helps your skin produce vitamin D.

UVA is considered the ‘bad guy’ because it penetrates your skin more deeply and causes more damage.  Not only that, but UVA rays are quite constant during ALL hours of daylight, throughout the entire year -- unlike UVB, which are low in morning and evening, and high at midday.

If you’ve ever gotten sunburned on a cloudy day, you now understand why; it’s from the deeply penetrating UVA!

The exposure you’re looking for is the exposure to UVB’s, which are at their greatest during midday, when the sun is at its highest in the sky. This is what Dr. Cannell refers to in this interview when he says you need to expose your skin to the high-noon sun -- which is contrary to conventional advice, which says to avoid tanning during “peak” hours.

You also need to be aware that you need far less sun exposure than you might think to reap its beneficial effects.

Most people with fair skin will max out their vitamin D production in just 10-20 minutes, or when your skin starts turning the lightest shade of pink. Some will need less, others more. The darker your skin, the longer exposure you will need to optimize your vitamin D production.

For more detailed guidelines on safe and appropriate sun exposure, please see my previous article, Vitamin D in Your Skin.



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Comment on This Article Community Comments (36)
 
 
Posted On Jan 06, 2009
So I wonder, at what point is it okay to bathe as not to wash off the vitamin D? At one point Dr. Mercola mentioned waiting until your skin had dried or an hour after exposure. Does this still apply?

 
Charles_Carlson
Novice User Novice User, Joined On 6/2006
Charles_Carlson  
Replied

Dr. Mercola
Master User Master User Joined On 12/1997
Dr. Mercola  
 
Posted On Jan 06, 2009
Thirty minutes is typically sufficient

 
 
 
Posted On Jan 22, 2009

Dr. Mercola,

This is a compound question.

Is it possible to quantify how much vitamin D your body needs to maintain an optimal level whether from sun exposure or from supplementation? How long does your body retain the stored vitamin D and what is the process and rate of the body burning or using the stored vitaminD?


 
Jeff in Vancouver
Novice User Novice User, Joined On 10/2007
Jeff in Vancouver  
 
 
 
Posted On Jan 22, 2009

I get outside every single day. Even just walking out the door, I instantly start to feel better. Sunny days are the best. Something about that natural sunlight that improves my mood and energy very quickly. Whenever I need to think creatively or solve a problem, I go outside.


 
OptaHealth
Novice User Novice User, Joined On 8/2007
OptaHealth  
Replied

agua
Novice User Novice User Joined On 5/2007
agua  
 
Posted On Jan 22, 2009

That really is a good way to improve one's mood. Staying indoors too much drives me crazy.


 
 
 
Posted On Jan 22, 2009

I got a UV meter from Oregon Scientific.  I wish Dr. Mercola would endorse this product here, because it is just a godsend for me.  I input my skin type (up to 4 from very light to very dark) and type of sunscreen (1 for no sunscreen; the meter's numbers match the SPF).  When I go out in the sun here in southern AZ, I push a button and the meter calculates how long I can stay in the sun without burning, counts it down, recalculates every 10 minutes, and beeps when it's time to go in.  At last I can get my D without worry.  When I started, my D levels were in the toilet at 14 - now they are in the mid-30s and rising, and I've never gotten a burn.

I also realized something.  Even if very little of the US has enough sun all year long, we seem to take that to mean most of us are out of luck for 6 months.  I am at the 32nd parallel, which is considered to not get enough sun in winter.  But when exactly does that occur?  All of December through February?  Or a week or two around the Winter Solstice?  Because your body retains D for a while after exposure, so a bad 3 weeks in midwinter isn't going to undo all the good one has done the rest of the year.  And I can wear shorts and light, short-sleeved shirts or even a swimsuit on warm January days, instead of exposing just the part of my face that isn't covered by a ski mask and hoping for the best.  These factors all need to be taken into account.


 
Wolfster
Novice User Novice User, Joined On 2/2008
Wolfster  
 
 
 
Posted On Jan 03, 2009
I didn't know about the soap washing off Vit. D. That is good to know. Does anyone know if spending more time with just face, arms and lower legs can generate as much Vit. D as sunbathing in a swimsuit?. Most of us aren't able to sunbath like that while at work. I worked at a daycare last summer and was able to spend a good bit of time in the sun but I couldn't wear a swimsuit. I was sleeveless and wore capris that I rolled up when outside. I ended up with a great tan.

 
rablpn
Savvy User Savvy User, Joined On 2/2007
rablpn  
Replied

Islander
Moderator User Moderator User Joined On 3/2007
Islander  
 
Posted On Jan 03, 2009
The more area exposed, the less time needed. If you could sunbathe in your birthday suit, it wouldn't take long to get your daily quota!


Aaltrude
Moderator User Moderator User Joined On 4/2007
Aaltrude  
 
Posted On Jan 04, 2009
Mmmm - that is one definite advantage to living in the country and working on your own farm. You can expose as much skin as you like or dare and there is no one to see you.

 
 
 
 
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