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AAD Addresses Vitamin D-Sun Myths

Posted: November 25, 2009

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For those with sensitive skin, sunscreens with non-chemical ingredients work best and will prevent irritation. Dr. Tanzi said the ingredients zinc oxide and titanium dioxide provide both UVA and UVB protection.

Myth: Using a higher SPF will ensure you don’t burn.
Dr. Tanzi explained that those who use sunscreen with a higher SPF may think they will not burn when exposed to UV light, but she said that is not true. In fact, actual sunscreen protection depends on many other factors, including skin type, the amount and frequency of sunscreen application, and the impact of activities such as swimming and sweating. As a result, sunburn can occur even when wearing a higher SPF sunscreen.

Another important factor Dr. Tanzi emphasized is that UVB protection does not increase proportionately with a designated SPF number. For example, an SPF of 30 screens 97% of UVB rays, while an SPF of 15 screens 93% of UVB rays and an SPF of 2 screens out 50% of UVB rays. However, not applying enough sunscreen or not covering all exposed areas may result in a lower SPF than the product contains.

“For adequate protection, sunscreens are best applied 15–30 minutes prior to going outside, approximately every two hours or immediately after swimming or sweating,” said Dr. Tanzi. “Research demonstrates that most people only apply 25–50% of the recommended amount of sunscreen, which is one ounce for the entire body or enough to fill a shot glass. Therefore, if only half the proper amount of SPF 15 is applied, the SPF has been reduced to an SPF of approximately 5, which is then inadequate protection.”

To address the issue of people not using enough sunscreen or reapplying improperly, the Academy recently increased its recommended SPF to a minimum of 30 for proper sun protection. Dr. Tanzi said that while sunscreen is important to protect against skin cancer, it is only one part of what should be an overall sun-protection program.