The Monk, above, with little sun exposure at age 72.
This 58 year old Native American woman, below
has had plenty of sun.
The question remains, how much is too much sun, and how much is not enough. The current recommendations are as follows.
The AAD says it is "deeply concerned" about the current claim by Dr. Michael Holick, director of the vitamin D laboratory at Boston University School of Medicine, that exposing unprotected skin to the sun several times a week is necessary to prevent vitamin D deficiency. Holick cites two studies that found inadequate levels of vitamin D among people in two northeastern cities where the sun's ultraviolet (UV) rays don't penetrate during winter months. According to Holick, always wearing sunscreen is tantamount to creating this same "winter-like" environment on the skin, causing vitamin D levels to drop.
"I am not aware of any scientific studies that support this claim," said Dr. David J. Leffell of the Yale School of Medicine Department of Dermatology. "In my two decades of practice, I've never seen vitamin D deficiency caused by lack of sun exposure due to sunscreen use, yet the evidence that UV rays from the sun cause skin cancer is overwhelming."
Leffell says the winter drop in vitamin D levels among northeastern residents is a normal process that is well-known and easily accommodated by dietary supplementation. He cites inadequate diet as a culprit in the "very small" portion of the population that is truly vitamin D deficient. For these people, Leffell says, deficiency can be offset by taking vitamin D supplements or drinking fortified milk.
Recommending even small amounts of sun exposure is bad advice, according to the Sun Safety Alliance, since there is no "acceptable" dose for carcinogens like UV radiation. Every exposure has some adverse affect—although this may be difficult to measure.
Phil Schneider, director of the Sun Safety Alliance, also finds Holick's position unsound. "The practical and factual advice communicated to the public is based on the well-documented fact that ultraviolet radiation from the sun is carcinogenic. Enjoy the outdoors, and protect yourself. Block the sun but not the fun is proper advice. The factual truth is that tanning is dangerous because it increases the risk for skin cancer."
Vitamin D is essential for maintaining proper health, including the body's absorption of calcium and the proper function of muscles. However, the experts agree that studies linking the nutrient to a reduced risk of a number of cancers are preliminary, and would not alter their recommendation of supplementing over sunning if proven true.
About Skin Cancer
One in five Americans will develop skin cancer during their lifetime, and it is one of the few cancers where the cause is known. Each year approximately one million new cases of skin cancer are diagnosed in the US, and over 91,000 Americans are diagnosed with melanoma, the most serious form of skin cancer. One person dies of melanoma every hour. Melanoma is also one of the few cancers that continues to rise—at a rate of 3 percent annually.
The American Academy of Dermatology recommends that everyone practice a comprehensive sun protection program, including avoiding outdoor activities when the sun's rays are strongest, seeking shade whenever possible, wearing a broad-spectrum sunscreen with a Sun Protection Factor (SPF) of at least 15 and reapplying every two hours.
About the American Academy of Dermatology (AAD)
Founded in 1938, the AAD is the largest, most influential, and most representative of all dermatologic associations. With a membership of over 14,000 dermatologists worldwide, the Academy is committed to advancing the diagnosis and medical, surgical and cosmetic treatment of the skin and nails; advocating high standards in clinical practice, education and research in dermatology, supporting and enhancing patient care for a lifetime of healthier skin. For more information contact the AAD at 1-888-462-DERM or www.aad.org.