One recent survey of Australian populations found that even at the end of summer, 30% of Australian boys were marginally vitamin D deficient, as was a much higher percentage of the elderly, particularly those with dark skin.
It also must be noted that sun exposure has a number of other health benefits, including promoting bone health and even just creating a sense of well-being, Dr. Armstrong added.
It has been suggested that receiving the equivalent of one minimal erythema dose to the hands and face per week is sufficient for vitamin D synthesis, Dr. Armstrong said. That amount of exposure, Dr. Berwick said, would translate into about 5–10 minutes per day spent in sunshine, two to three times per week.
On the other hand, no melanoma experts appear to be recommending that campaigns to warn about the dangers of too much sun exposure should be abandoned.
Addressing that question directly in two separate lectures, Martin A. Weinstock, M.D., noted that sun education campaigns appear to have made little difference in behavior.
He said that regular self-performed skin examination appears to be the more important melanoma strategy because studies show that it can be encouraged and that it significantly affects mortality.
But both approaches are still needed, said Dr. Weinstock, a professor of dermatology at Brown University, Providence, R.I. Evidence still implicates sun exposure in the genesis of melanoma, and primary prevention will always be important, he said.
“Obviously, there are new hypotheses out there, but a lot remains to be elucidated,” he said. “People still need to take measures for both prevention and early detection.”