Can Sunshine Help Prevent Cancer?

Some Scientists Think Too Little Sun Is Worse Than Too Much

(AP) 
People in the northeastern United States and northerly regions of the globe like Scandinavia have higher cancer rates than those who get more sunshine year-round.

During short winter days, the sun's rays come in at too oblique an angle to spur the skin to make vitamin D. That is why nutrition experts think vitamin D-3 may be especially helpful during winter, and for dark-skinned people all the time.

But too much of the pill variety can cause a dangerous buildup of calcium in the body. The government says 2,000 IUs is the upper daily limit.

On the other hand, it's almost impossible to overdose when getting vitamin D from sunshine. However, it is possible to get skin cancer. And this is where the dermatology establishment and Dr. Michael Holick part company.

Thirty years ago, Holick helped make the landmark discovery of how vitamin D works. Until last year, he was chief of endocrinology, nutrition and diabetes and a professor of dermatology at Boston University. Then he published a book, "The UV Advantage," urging people to get enough sunlight to make vitamin D.

Skin cancer is rarely fatal, he notes. The most deadly form, melanoma, will account for only 7,770 of the 570,280 U.S. cancer deaths expected this year.

Repeated sunburns — especially in childhood and among very fair-skinned people — have been linked to melanoma, but there is no credible evidence that moderate sun exposure causes it, Holick contends.

"The problem has been that the American Academy of Dermatology has been unchallenged for 20 years," he says. "They have brainwashed the public at every level."

The head of Holick's department, Dr. Barbara Gilchrest, called his book an embarrassment and stripped him of his dermatology professorship, although he kept his other posts.

Earlier this month, the dermatology academy launched a "Don't Seek the Sun" campaign calling any advice to get sun "irresponsible." It quoted Dr. Vincent DeLeo, a Columbia University dermatologist, as saying: "Under no circumstances should anyone be misled into thinking that natural sunlight or tanning beds are better sources of vitamin D than foods or nutritional supplements."

That opinion is hardly unanimous, though, even among dermatologists.

"The statement that 'no sun exposure is good' I don't think is correct anymore," said Dr. Henry Lim, chairman of dermatology at Henry Ford Health System in Detroit and an academy vice president.