It seems the good news regarding vitamin D just keeps coming. In a recent study carried out by senior study author Dr. Kurt Lu, an assistant professor of dermatology at Case Western Reserve University in Cleveland, Ohio, high doses of vitamin D taken one hour after sunburn significantly reduce skin redness, swelling, and inflammation. Dr. Lu and his colleagues recently reported their findings in the Journal of Investigative Dermatology.
Sunburns may often be short-term nuisances, but they could ultimately lead to skin cancer, the most commonly diagnosed cancer in the U.S. Skin cancer can range from less serious to deadly, affecting nearly 10,000 people each day.
According to the Centers for Disease Control and Prevention (CDC), just fifteen minutes of ultraviolet (UV) radiation from the sun is enough to cause skin damage. As such, the CDC recommend wearing broad-spectrum sunscreen (SPF15 or higher), a wide-brimmed sun hat, sunglasses, and other protective clothing - such as a long-sleeved shirt - to help prevent UV-related skin damage. However, more than a third of Americans who know this still get sunburnt, which can result in red, sore, blistering skin. The new study from Dr. Lu and team, however, suggests that vitamin D supplementation might help to ease the symptoms of sunburn.
In the study, 20 participants were randomized to receive a placebo pill or 50,000, 100,000, or 200,000 IU of vitamin D one hour after a small UV lamp "sunburn" on their inner arm. Researchers followed up with the participants 24, 48, 72 hours and 1 week after the experiment and collected skin biopsies for further testing. Participants who consumed the highest doses of vitamin D had long-lasting benefits -- including less skin inflammation 48 hours after the burn. Participants with the highest blood levels of vitamin D also had less skin redness and a jump in gene activity related to skin barrier repair.
"We found benefits from vitamin D were dose-dependent," said Kurt Lu, MD, senior author on the study and Assistant Professor of Dermatology at Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center. "We hypothesize that vitamin D helps promote protective barriers in the skin by rapidly reducing inflammation. What we did not expect was that at a certain dose, vitamin D not only was capable of suppressing inflammation, it was also activating skin repair genes."
The trial is the first to describe acute anti-inflammatory benefits from taking vitamin D. According to the authors, despite widespread attention given to vitamin D deficiency, "there is a lack of evidence demonstrating that intervention with vitamin D is capable of resolving acute inflammation." By measuring gene activity in the biopsies, the researchers also uncovered a potential mechanism behind how vitamin D aids skin repair. The results suggest vitamin D increases skin levels of an anti-inflammatory enzyme, arginase-1. The enzyme enhances tissue repair after damage and helps activate other anti-inflammatory proteins.
Dr. Lu points out that the trial tested very high doses of vitamin D that far exceed daily allowances. The Food and Drug Administration's recommended adult daily allowance for vitamin D is 400 IU. Said Lu, "I would not recommend at this moment that people start taking vitamin D after sunburn based on this study alone. But, the results are promising and worthy of further study." Lu and colleagues are planning additional studies that could inform treatment plans for burn patients.
Vitamin D is considered an essential nutrient. Vitamin D not only aids bone health by promoting calcium absorption, but it also plays a role in nerve signaling and immune system functioning. In other studies, vitamin D has been shown to help ward off depression, boost weight loss, protect the heart and more. Vitamin D is naturally present in small amounts in some foods, including fatty fish, cheese, and eggs. However, the body's main source of vitamin D is the sun. Our skin contains a chemical compound called 7-Dehydrocholesterol. When exposed to sunlight, this compound produces vitamin D-3. However, due to the risks of excess UV exposure, getting all the vitamin D we need from sunlight is not always possible. For people who are unable to get enough vitamin D through diet and sunlight exposure, vitamin D supplements are often recommended.