The Real Killer in Sunlight -- UVA

March 31, 2009 | 37,881 views | + Add to Favorites

Dr. Dianne Godar of the U.S. Food and Drug Administration (FDA) has conducted a study indicating that UVA light -- not the UVB light that causes suntans and allows your body to produce vitamin D -- may be responsible for the melanoma epidemic.

What’s more, the UVA light, unlike UVB, can pass through window glass, meaning you can still be exposed to it while you are indoors or in your car.

UVB, on the other hand, appears to be protective against melanoma -- or rather, the vitamin D your body produces in response to UVB radiation is protective. Dr. Godar points out that the melanoma epidemic began long before sunbeds, and that the dramatic melanoma increase occurs primarily in indoor workers, not outdoor workers.

Low vitamin D levels actually predict melanoma, and all-year tans protect against melanoma. Melanoma patients who expose themselves to the sun live longer than those who don't.

Vitamin D Dose Recommendations
Age	Dosage
Below 5	35 units per pound per day
Age 5 - 10	2500 units
Age 18 - 30	5000 units
Pregnant Women	5000 units
WARNING: There is no way to know if the above recommendations are correct. The ONLY way to know is to test your blood. You might need 4-5 times the amount recommended above. Ideally your blood level of 25 OH D should be 60ng/ml.

Dr. Mercola's Comments:

For decades now, public health officials have been warning that exposure to ultraviolet (UV) radiation from the sun increases your risk of developing melanoma, the most serious type of skin cancer.

But something doesn’t quite add up with this generalized warning, because an epidemic of melanoma has broken out among indoor workers. In fact, indoor workers get three to nine times LESS solar UV exposure than outdoor workers get, yet only indoor workers have increasing rates of melanoma -- and the rates have been increasing since before 1940.

So what’s really going on here?

For point of discussion there are two primary types of UV rays from sunlight that you need to be concerned with, the vitamin-D-producing UVB rays, and the skin-damaging UVA light.

Both UVA and UVB can cause tanning and burning, although UVB does so far more rapidly. UVA, however, penetrates your skin more deeply than UVB, and may be a much more important factor in photoaging, wrinkles and skin cancers.

This latest study suggests that indoor workers may have increased rates of melanoma because they’re exposed to sunlight through windows, and only UVA light, unlike UVB, can pass through window glass.

At the same time, these indoor workers are missing out on exposure to the beneficial UVB rays, and have lower levels of vitamin D. So it’s the combination of exposure to UVA light and lower vitamin D levels that appears to be causing the increased rates of melanoma, and the indoor workers could clearly benefit from spending some time outdoors in the sun.

Why Optimal Sun Exposure Lowers Your Risk of Cancer

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 using 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.

Why is this?

Dr. John Cannell, one of the leading authorities on vitamin D and founder and executive director of the Vitamin D Council, does an excellent job of explaining it in this video but to give you a summary, nature has devised a very clever strategy to keep the sun from damaging your skin.

It is important to realize that the sun can increase genetic damage in your skin and cause skin cancer, especially if you get regularly sunburned.

But what the media and many health “experts” fail to appreciate and explain to the public is that regular and safe exposure to sunlight or safe tanning beds allows vitamin D to be formed in your skin. The vitamin D then directly moddulates genes in your skin that actually help prevent the types of abnormalities that ultraviolet light causes.

And it’s not just melanoma that vitamin D helps protect you from. 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.

If You Wear Sunscreen, You Negate This Natural Cancer Protection

If you avoid the sun entirely, or slather on sun block whenever you go out, your skin will be unable to produce vitamin D, and you’ll be left without this built-in cancer protection.

Further, for many years sunscreens only protected you from the beneficial UVB rays, while letting through skin-damaging UVA light. Even today, while most sunscreens do a good job blocking UVB, fewer filter out all of the UVA.

Not only that, but UVA rays are quite constant during ALL hours of daylight, throughout the entire year -- unlike UVB, which are low in the morning and evening, and high at midday.

So if you do decide to use sunscreen, make sure you choose one that is non-toxic and blocks both UVA and UVB rays. Two non-toxic ingredients that scatter both UVB and the more damaging UVA rays are titanium dioxide and zinc oxide. They’ve been used all over the world for over 75 years as safe sunscreens.

However, keep in mind that you’ll still need to spend time in the sun without any sunscreen at all in order to optimize your vitamin D levels.

When is the Best Time to Go Out in the Sun?

The optimal time to be in the sun for vitamin D production is as near to solar noon as possible. That would be between roughly 10:00am and 2:00pm.

During this time you need the shortest exposure time to produce vitamin D because UVB rays are most intense at this time. Plus, when the sun goes down toward the horizon, the UVB is filtered out much more than the dangerous UVA.

This information is just beginning to permeate through the mainstream media, so let me repeat and emphasize this important point …

If you want to get out in the sun to maximize your vitamin D production, and minimize your risk of malignant melanoma, the middle of the day is the best and safest time to go.

You just need to be very careful about the length of your exposure. Remember you only need enough exposure to have your skin turn the lightest shade of pink. This may only be a few minutes for some.

Once you reach this point your body will not make any additional vitamin D and any additional exposure will only cause harm and damage to your skin.

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.

To learn more about sunlight and vitamin D, including why I recommend getting your levels tested and how to use the sun for cancer prevention, please set aside an hour to watch my free lecture on vitamin D.

How Vitamin D Performance Testing Can Help Optimize Your Health

Additionally, a robust and growing body of research clearly shows that vitamin D is absolutely critical for good health and disease prevention. Vitamin D affects your DNA through vitamin D receptors (VDRs), which bind to specific locations of the human genome. Scientists have identified nearly 3,000 genes that are influenced by vitamin D levels, and vitamin D receptors have been found throughout the human body.

Is it any wonder then that no matter what disease or condition is investigated, vitamin D appears to play a crucial role? This is why I am so excited about the D*Action Project by GrassrootsHealth. It is showing how you can take action today on known science with a consensus of experts without waiting for institutional lethargy. It has shown how by combining the science of measurement (of vitamin D levels) with the personal choice of taking action and, the value of education about individual measures that one can truly be in charge of their own health.

In order to spread this health movement to more communities, the project needs your involvement. This is an ongoing campaign during the month of February, and will become an annual event.

To participate, simply purchase the D*Action Measurement Kit and follow the registration instructions included. (Please note that 100 percent of the proceeds from the kits go to fund the research project. I do not charge a single dime as a distributor of the test kits.)

As a participant, you agree to test your vitamin D levels twice a year during a five year program, and share your health status to demonstrate the public health impact of this nutrient. There is a $65 fee every 6 months for your sponsorship of the project, which includes a test kit to be used at home, and electronic reports on your ongoing progress. You will get a follow up email every six months reminding you "it's time for your next test and health survey."

[+] Sources and References

Medical Hypotheses April 2009; 72 (4): 434-443

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