Our relationship with the sun is complex. The sun provides us with Vitamin D, a much-needed nutrient that assists in calcium absorption, which helps prevent diseases like osteoporosis by strengthening our bones. Moderate sun exposure has been proven to enhance our moods, improve our quality of sleep, and decrease stress.
An online search for information about sunscreen probably made you feel less than sunny about coating you and your family with these lotions and creams. Dr. Jennifer Lin, as assistant professor of dermatology at Harvard Medical School, and N.C. Cooperative Extension urges the public to not let myths deter you from protecting your skin.
Sunscreen does block ultraviolet B rays, which are important in generating Vitamin D in the skin. However, because most people apply far less than the recommended amount (about a teaspoonful to the face and one shot glass–sized amount to the body) of sunscreen, users typically aren't deficient in vitamin D. Your doctor can recommend a vitamin D supplement, such as 800 IU of vitamin D3 daily if you’re concerned about a vitamin D deficiency.
The term “sunscreen” typically refers to chemical sunscreens which contain active ingredients that absorb UV rays to prevent damage. Typical ingredients include oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate. “Sunblock” usually refers to physical sunscreens. These sunscreens are more of a physical barrier, bouncing the UV rays off the skin and protecting the skin beneath from their harmful effects. The most critical, active ingredients are zinc oxide and titanium dioxide.
Oxybenzone has received the worst press because of concerns that it may act as a hormone disruptor. A hormone disruptor is a chemical that has the ability to cross cell membranes and may interfere with your body's natural hormone production. There has been no conclusive evidence that oxybenzone is harmful to humans. Studies that support these claims were done in rats, where the rats were actually fed oxybenzone. It would take an individual 277 years of sunscreen use to achieve the equivalent systemic dose that produced effects in these rat studies, according to a 2017 study in the Journal of the American Academy of Dermatology.
Extension does not recommend that you avoid sunscreens with oxybenzone, and if people choose to do so, they should be aware that the chemical exists in many other common products of daily use such as plastic, hairspray, and nail polish.
Sunscreen alone is not an all-inclusive sun safety strategy. Sunscreen will not block all of the sun’s UVA and UVB rays, even when applied correctly. Seeking shade, utilizing sun-protective clothing, wearing a hat and UV-blocking sunglasses and reapplying sunscreen regularly (make sure to apply a complete coat about 15 minutes before going outdoors) can all help protect you against burns and skin damage.
