One of the main ways we get vitamin D into our bodies is via sun exposure. Of course, it helps if we’re not all covered up by clothing in the dead of winter in the Great White North. On the other hand, while light-skinned Caucasians can obtain upwards of 3,000 units of vitamin D in just 5-10 minutes by wearing shorts & t-shirt under the noon day sun during the summer, sunscreen tends to diminish this benefit dramatically. We’ve all heard about the benefits of higher vitamin D levels so why bother with sunscreen? Well, not only does routine sunscreen application tend to decrease sun damage (otherwise known as wrinkles), it also decreases one’s risk for skin cancer.
Now I tend to be a lumper rather than a splitter so I look at all skin cancers as bad. You’ll never hear me argue that any skin cancer is a good thing but clearly some types are worse than others, namely melanoma. It turns out that we have plenty of gold standard data from randomized controlled trials (RCT) that sunscreen prevents squamous cell skin cancer. But it took a recent commentary in JAMA to direct me towards another RCT published earlier this year in a more obscure journal (at least to this family doc) that concluded that sunscreen application can also prevent melanoma.
Specifically, the authors randomized 1,621 Australians to daily or discretionary application of sunscreen for 4 years and then followed them for another 10 years. New melanomas were diagnosed 50% less frequently in those who applied sunscreen daily compared to those who were less rigorous about it. Invasive melanoma diagnoses were reduced dramatically as well.
But what about our vitamin D? Personally, I’d rather eat more vitamin D fortified foods and/or take an additional vitamin D supplement rather than run the risk of developing any type of skin cancer, but the choice is yours.
About the author: Dr. Alvin B. Lin served as a Clinical Assistant Professor in the Department of Family and Community Medicine at the University of Nevada, School of Medicine since 2004 and recently became an Adjunct Assistant Professor of Family Medicine and Geriatrics at the Touro University Nevada College of Medicine. Along the way, he has written many articles, given many presentations, and made himself available to both patients and colleagues. He plans to continue more of the same (but without the middle-man!). http://alvinblin.blogspot.com
Editors Note: This article was previously posted on alvinblin.blogspot.com