Vitamin D and sun exposure: Here’s what you should know
Most of us know that the best way to avoid a nasty sunburn is to lather up with sunscreen. But in doing so, are we depriving ourselves of necessary vitamin D?
Vitamin D, also known as the “sunshine vitamin” because it is produced in your skin in response to sunlight, is essential for several reasons, including maintaining healthy bones and teeth. It may also protect against a range of diseases and conditions, such as type 1 diabetes. Vitamin D has the important role of helping the body absorb calcium and phosphate from our diet.
Inadequate vitamin D levels can increase your risk for numerous health problems including cancer, osteoporosis, heart disease, asthma and even the common cold.
Sun exposure in moderation is key
One of the best sources of vitamin D is the sun. However, there is a longstanding debate among many health care professionals on how much sunlight is appropriate to balance between positive and negative effects of solar UV exposure.
The American Academy of Dermatology proposes that most problems with vitamin D deficiency are nutritional in nature; and even though sunlight is necessary to synthesize vitamin D, it takes only 10 to 15 minutes of exposure to arms, legs, abdomen and back, two to three times a week, followed by good sun protection.
That minor amount of exposure produces all the vitamin D your body can use. After that, your body automatically starts to dispose of vitamin D to avoid an overload of the vitamin, at which point your sun exposure is giving you nothing but sun damage without any of the presumed benefit.
Therefore, tanning or prolonged exposure to sunlight will not increase your vitamin D levels more than what you are getting. Instead, the AAD recommends getting vitamin D from a healthy diet, which includes naturally enriched vitamin D foods, fortified foods and beverages and/or vitamin supplements.
Know your vitamin D infused foods
Because very few foods naturally have vitamin D, it is important to become familiar with those that do.
Fatty fish such as salmon and mackerel are among the best sources of vitamin D. In fact, a 3.5-ounce serving of canned salmon can provide 50 percent of the reference daily intake. Beef liver, cheese and egg yolk provide small amounts. Mushrooms also contain this vitamin if grown under UV lights.
Vegan foods high in vitamin D include fortified soy products like tofu, soy milk, soy yogurt and fortified cereals.
A word of caution against prolonged sun exposure
The rapid onset of DNA damage and the harmful cumulative effects of sun exposure throughout our lives are the reasons that the vast majority of dermatologists recommend more sun protection, not less.
The Skin Cancer Foundation recommends daily use of not just an SPF 15+ broad spectrum sunscreen, but also other forms of sun protection such as shade and sun-protective clothing. Fortunately, studies have found that you can still reap the protective benefits of sunscreen without compromising vitamin D levels.
A vitamin D enriched diet, along with brief and protected sun exposure, can help the body become more vitamin D sufficient. If you are concerned about your level of vitamin D, discuss options for obtaining sufficient dietary or supplementary sources with your physician.
Dr. Daniel Shurman of Pennsylvania Dermatology Partners in Amity Township completed his dermatology training at Thomas Jefferson University. He is fellowship-trained in both Mohs micrographic surgery and procedural dermatology, and his research interests include medical genetics, antibiotics in dermatologic surgery and wound healing.