The health benefits of carefully increased UV exposure — from the sun or from sunbeds — outweigh the disputed and often-oversimplified risks of permanent skin damage, according to an Oslo University study published in the journal Public Health Nutrition.

The study — supported by the Norwegian Cancer Society — pointed out that increased sun exposure to the Norwegian population would elevate depressed vitamin D blood levels by 25 nmol/L, which “might result in 4,000 fewer internal cancers and about 3,000 fewer cancer deaths overall” — a finding they credit to their previous work and Harvard University vitamin D researcher Dr. Edwin Giovannucci’s previous paper published in the Journal of the National Cancer Institute.

Dr. Johan Moan, of the University of Oslo, was the lead author of the new paper. Contrasting the UV-induced health benefit with the possible risks of UV exposure, the authors wrote, is more complex than many believe.

“Sun exposure is commonly supposed to be the main cause of cutaneous malignant melanoma in most populations. However, the matter is disputed,” Moan and colleagues wrote. “Intermittent sun exposure and severe sunburn in childhood are associated with an increased risk of (melanoma)” but “occupational exposure (farmers, fisherman) and regular weekend sun exposure are associated with decreased risk… Sun exposure may even protect against (melanoma) on shielded sites.”

They continued, “It has also been observed that patients with the highest blood levels of vitamin D have thinner (melanomas) and better survival prognosis.”

The paper noted that while some studies suggest a relationship between sunbed use and melanoma, others show no association. Making any assessment more difficult, “There has been a significant increase in the number of sunbed exposures in Norway after 1990, but (melanoma) incidence rates among persons younger than 50 years have stabilized.”

The authors want health authorities to take all of this into better perspective rather than issuing blanket anti-UV statements.

“Due to the fear of skin cancer, health authorities warn against sun and sunbed exposure. This policy, as well as the recommended vitamin D doses, may need revision,” the authors write. “UV from the sun and sunbeds is the main vitamin D source. Young people with white or pigmented skin in northern Europe have low vitamin D status. A number of health benefits from sufficient levels of vitamin D have been identified.”