Go outside without sunscreen and risk melanoma, the deadliest version of skin cancer. Fail to get enough sunlight and risk dying of heart disease, cancer, diabetes and a host of other awful maladies. It's enough to cause paralysis-by-analysis over a simple walk in the park.
In the past few months, a spate of surprising studies has added to a growing body of evidence suggesting that getting adequate amounts of vitamin D — the "sunshine vitamin" — protects against the risk of not only the osteoporosis and depression that people have long known about, but also colon cancer, breast cancer, heart disease, rheumatoid arthritis, diabetes and even multiple sclerosis.
This summer, media outlets such as the Los Angeles Times, U.S. News & World Report and The Dallas Morning News have responded to the studies by vaunting the value of the sun. They've also implied — and even reported — that sunscreen enthusiasts are taking their message too far.
"Don't run from the sun's vitamin D benefits," proclaimed the Morning News in July.
Meanwhile, in a newly launched national ad campaign, the American Academy of Dermatology is trumpeting what seems to be the opposite message: Limit your exposure to ultraviolet rays. Called "Indoor Tanning Is Out," the campaign that began in July includes TV public-service announcements featuring the testimonials of young women talking about the link between indoor tanning and melanoma.
The academy's warnings about UV exposure don't stop at the tanning booth.
Dr. William Hanke, president of the American Academy of Dermatology, told Miller-McCune.com that there is almost never a good reason to stay out in the sun without protection.
"If you're going to play golf or tennis, play early in the day, use sunscreen, cover up," he said. "We're not advocating, ‘Don't go outdoors.' What we're advocating is, ‘Protect your skin from UV radiation.' It's the only skin you're ever going to have."
It's a quandary. How can we reduce melanoma risk without cutting off the vitamin D supply that, according to recent studies, protect against all those other diseases?
Researchers on both sides of the debate agree — to a point, at least — that there's an answer: vitamin D supplements.
Certain foods can also be helpful, but not as much as you might think.
Vitamin D generally cannot be found in fruits or vegetables and really only exists naturally in fish, especially of the larger ocean-dwelling variety, such as tuna. Also, certain foods, such as milk and orange juice, have been artificially fortified with the vitamin. But one would have to down 20 glasses or milk a day to get the minimum 1,000 International Units of vitamin D that institutions such as the Harvard Public School of Health and University of California, Berkeley now recommend.
In general, researchers — sun enthusiasts and sun-phobics alike — are urging people to take vitamin D supplements every day. Younger adults generally are recommended to take about 1,000 International Units; older adults, 2,000. These amounts greatly exceed the official recommendations of the Institute of Medicine, which suggests between 200 and 600 units, but many now think the official guidelines are out of date.
In any case, it's probably no surprise that Hanke gets his daily 2,000 units of Vitamin D through supplements.
DeLuca's research on the benefits of vitamin D spans decades and has been extensively cited in media articles focusing on the benefits of getting more sun. But DeLuca himself doesn't believe there's much need to go into the sun without protection.
"I think the only real way to go is by mouth," he told Miller-McCune.com.
As for going into the sun unprotected, he added, "I'm not going to do it because I don't want to deal with the skin-cancer risk."
In the late 1960s, DeLuca discovered that vitamin D must pass through the liver and kidney to work its magic. This paved the way for synthesis, and then vitamin D-based drugs — such as DeLuca's namesake Hectorol — used to combat bone diseases like osteoporosis.
DeLuca concedes sunlight can be beneficial, although he cautions that the surprising epidemiological studies on vitamin D's relationship to protecting the body from those diseases so far have merely pinpointed a strong correlation, not causation. Still, he said as early as the late 1970s, it was observed that multiple sclerosis rates were lowest in high-sunlight areas and vice versa.
Nonetheless, DeLuca said he is in complete agreement with the dermatologists who say it's generally a bad idea to go out into the sun without protection.
"I like to garden, but I wear big hats and protect my body with clothes," he said.
DeLuca said there is no meaningful difference between how the body processes vitamin D from a capsule and from sunlight, except the former doesn't leave a person vulnerable to skin cancer.
"I don't want to tangle with melanoma," he said.
Even one of America's most controversial sun enthusiasts is a vitamin D pill-popper. Boston University Medical Center professor Michael Holick wrote the incendiary book The UV Advantage, which advocated getting more sun.
Despite Holick's love for the sun, he still ingests 1,400 units of vitamin D in the form of a capsule and a multivitamin every day.
But unlike DeLuca, Holick still urges people to get moderate amounts of direct sunlight.
Holick's career actually began as a grad student working under DeLuca. He went on to become the chief of endocrinology, nutrition and diabetes and a professor of dermatology at Boston University. But in 2004, the head of the dermatology department fired him from his dermatology professor post in response to his book, calling it "an embarrassment." (He is now a professor of medicine, physiology and biophysics at the university.)
Holick believes he was punished for challenging the anti-sun dogma of the dermatology world. He also believes it's unrealistic to expect every man, woman and child in the world to take the supplements that he does.
"Most humans on this planet depend on and have always depended on the sun for their vitamin D," he said.
In addition to taking supplements, Holick makes a point to absorb sunlight for two to three hours a week while cycling or playing tennis. He said he typically applies sunscreen to his face but leaves his arms and legs bare. His vitamin D blood levels, he boasts, are usually right in line with what many researchers now recommend: between 40 and 50 nanograms per milliliter.
Holick's recommended dosage for sunlight depends on a range of variables, such as a person's skin color and whereabouts. In general, the darker the skin — and the farther away from the equator — the longer a person needs to stay in the sun to absorb healthy levels of vitamin D.
A fair-skinned person, say, at Cape Cod around noon in June, he said, should get maybe 10 to 15 minutes a day, but African Americans generally need to be out in the sun five-to-10-times longer, he said.
When it comes to melanoma, which kills about 8,000 Americans every year, Holick's view is nuanced. On the one hand, he believes moderate sunlight exposure actually decreases one's risk of acquiring the disease, citing a study of Navy personnel in 1990. (The surprising study found that sailors who worked indoors displayed higher rates of malignant melanoma that those who worked outdoors.)
But burning, Holick said, is always bad.
"Never get a sunburn," he said. "It's the most likely way to increase your risk of malignant melanoma. ... That's why moderation is so important."
Although Holick says he doesn't advocate indoor tanning, his studies are routinely celebrated by the indoor tanning industry. In a 2007 study, published in the New England Journal of Medicine, Holick concluded that adults who visited a tanning salon at least once a week showed healthier levels of vitamin D at the end of the winter than adults who merely took a multivitamin. (Multivitamins are not the same as vitamin D supplements. In general they contain just 400 units of vitamin D, compared to the supplements, which usually contain 1,000. The Harvard School of Public Health suggests taking one of each daily.)
Holick's study was panned by critics who noted that it was partly funded by the indoor tanning industry; he responded that the industry's support amounted to just 2 percent of his budget.
One major Holick supporter, the Indoor Tanning Association, in March launched its own public relations gambit to counter the campaign of the American Association of Dermatology. The association's home page is filled with links to recent articles lauding the benefits of the sun.
Association spokeswoman Sarah Longwell said there is no proof that tanning beds cause melanoma.
"It's been frustrating to see dermatologist after dermatologist speak about it as though it was a fact," she said. Longwell conceded that sun-burning is bad and said the industry standard is to encourage moderation by imposing limits on the number of visits a person can make in a specified period of time.
"One thing about tanning salons that is superior to sun exposure is that it is a controlled environment," she said. "When I go out in the sun, I am likely to burn. I fall asleep, my foot gets sunburned because I missed it with sun lotion."
But one thing the American Association of Dermatology has that its adversary doesn't is the power of anecdotal stories. Take 24-year-old Meghan Rothschild, whose story is featured in the association's print ads.
A member of a fair-skinned family in Massachusetts, Rothschild was no sun-worshipper as a teenager. But when she returned from a family vacation in Florida with an attractive tan on her stomach at age 17, she decided to maintain it.
Over the course of about 2½ years, she went to a tanning salon once a week, for about 20 minutes each time.
"I'd actually been told tanning was much safer than the sun," Rothschild told Miller-McCune.com.
When Rothschild discovered a slightly itchy mole on her stomach, she was worried enough to see a doctor, but the doctor told her it didn't look like anything malignant. She nonetheless had it removed, and went to the tanning salon the same day. But in January of 2004, when getting the stitches removed, she was startled by the grave expression on the face of her new doctor.
"Is there anyone here with you?" he asked her. Puzzled, she said no. Then, he dropped a bomb: she had stage II melanoma.
"He starts throwing out words like ‘cancer,' ‘survival rate,' ‘lymph nodes' and ‘treatment,'" Rothschild remembers. "Basically I'm traumatized for the next two weeks."
A month later, after a three-hour surgery, a six-inch chunk of skin was removed from her stomach, leaving a C-shaped scar. The surgery required 75 internal and external stitches.
Although Rothschild's extended family has some history of cancer — her grandmother had breast cancer and an aunt had stomach cancer — Rothschild said she is the only one who has contracted melanoma. She firmly believes the tanning bed caused it.
The cancer has remained at bay, but now Rothschild doesn't go anywhere outside without sunblock. Complicating matters, she works as an event-promotions manager at Six Flags, which requires her to spend much of her time outdoors. "I can't hibernate — I'm 24 years old," she said. "I just have to be really proactive."
Meanwhile, vitamin D experts warn that it's also possible to overdo it with the supplements.
When this happens, a person starts to experience the hardening of soft tissues, such as kidneys. Oddly, this cannot happen through sun exposure: Once the body burns, it stops producing vitamin D.
"The debate now is where is the safe place, and where is even 1 percent of the population at risk," DeLuca said. "We don't know that. Some people think we can go as high as 10,000 units a day. I think 2,000 units a day is safe."
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