Sun exposure

Sun Exposure

New research shows that to obtain optimal vitamin D supplementation from the Sun with minimal risk of developing malignant melanoma (MM), the best time for sun exposure is at noon.

This means that common health recommendations given by authorities in many countries – that sun exposure should be avoided from 3 to 5 hours around noon and postponed to the afternoon – may be wrong and could even promote MM.

This is partly because the action spectrum for MM is likely to focus on longer wavelengths than those for vitamin D generation. This is an update to my own personal knowledge, as for many years I have advised people to avoid the sun from 10 am to 2 pm due to the risk of sunburn.

Well, it turns out that this is the case where little knowledge can be dangerous. Malignant melanoma (MM) is the most severe form of skin cancer, accounting for about three-quarters of all skin cancer deaths.

New research now supports that while avoiding the sun at noon will reduce the risk of painful burns, it will increase the risk of cancer.

How can this be?

If you are a member of my Mercola circle and heard last month’s expert interview with Dr. William Grant, an internationally recognized researcher and vitamin D expert, you already have your answer.

Although he was not the author of the previous study, his research found the same conclusions: that sun exposure at noon is best for your health. “Our recommendation is based on our work in England, Norway, and the United States, and states that the best time to be in the sun for vitamin D production is as close to solar noon as possible.

That would be between 10:00 am and 2:00 pm. The reason is twofold, explains Dr. Grant: • First, a shorter exposure time is needed because UVB radiation is more intense. • The second reason is that when the sun sets towards the horizon, UVB rays are filtered much more than UVA.

And it turns out that the long-wave ultraviolet rays called UVA, which range from about 320 to 400 nanometers, are highly correlated with melanoma – while UVB radiation is what produces vitamin D, and that is from 290 to 315 nanometers.

The Concept

This is truly a profound concept, and it is starting to penetrate through the media. For example, “U.S. News & World Report” published an article on sun exposure time, and in it, Robyn Lucas, an epidemiologist at the Australian National University, agreed with these findings. “I think we all need a little unprotected sun exposure during the middle of the day when the sun is at its highest and UVB can penetrate the atmosphere,” she said.

“So let me reiterate this crucial new information: If you want to sunbathe to maximize vitamin D production and minimize the risk of malignant melanoma, noon is the best and safest time to do so.”

“Squamous cell carcinoma has always been linked to ultraviolet B radiation, while melanoma has always been linked to UVA rays or to sporadic sunburns in youth and things like that,” says Dr. Grant.

They Educate Us

“And that’s why dermatologists, telling people to wear sunscreen and avoid the sun at noon, are actually giving recommendations that lead to an increase in melanoma.

And it’s because they haven’t looked closely at the wavelengths related to melanoma, so they simply didn’t realize they were giving bad advice.” Both UVA and UVB rays can cause tanning as well as burning, although UVB rays do so much more quickly.

UVA rays, however, penetrate the skin more deeply than UVB, and are thought to be a much more important factor in photo-aging, wrinkles, and skin cancer. Getting sun exposure will reduce your cancer risk… it won’t increase it! Obtaining about 2,000 to 4,000 IU of vitamin D daily can help reduce cancer risk by up to 50%! And according to Dr. Grant, nearly 30% of cancer deaths – which amounts to 2 million worldwide and 200,000 in the United States – could be avoided each year with higher levels of vitamin D.

However, most people only get between 250 and 300 IU daily from their diet, so another source is essential, and ideally, that would be the sun. The duration of time spent in the sun is also critical. A common myth, aside from avoiding sun at noon, is that occasional exposure of the face and hands to sunlight is “enough” to achieve healthy vitamin D levels.

For most of us, this is inadequate and miserable exposure to bring vitamin levels into the healthy range. It is necessary to expose large portions of your skin to the sun, and you need to do so for more than just a few minutes. In fair-skinned individuals, the balance occurs within 20 minutes of ultraviolet exposure. It can take 3 to 6 times longer for pigmented skin to reach the skin’s vitamin D balance concentration.

Conclusion

Therefore, considering that you need to gradually increase your time, starting in the spring, you should aim for exposing large areas of your skin to the sun, up to 20 minutes or up to 2 hours depending on your skin type and environmental factors. Longer exposures will be necessary if sunbathing outside peak ultraviolet light hours (before 12 pm or after 3 pm) or early or late summer (April or September). You are probably wondering, when fall and winter approach, what to do when it’s too cold for sun exposure.

In the winter months, if you have checked your vitamin D levels and found them low, you can take a vitamin D3 (cholecalciferol) supplement, which is the type of vitamin D found naturally in foods like eggs, organ meats, animal fat, cod liver oil, and fish. Continue monitoring your vitamin D levels during this time, however, to avoid overdose.