Most people know that sun-sourced vitamin D is good for their bones. So could avoiding the sun to reduce skin cancer risk weaken your bones?
A new study brings a reassuring answer: "Sun-protective" behavior — wearing long sleeves, seeking shade or using sunscreen — "was not associated with decreased bone mineral density or increased risk of osteoporotic fracture," the researchers concluded.
One expert who wasn't connected to the study said the findings should put people's unease to rest.
"It is critical that patients understand that proper sun protection does not make them more at risk for osteoporosis and is important for preventing life-threatening skin cancers, such as malignant melanoma," said Dr. Michele Green. She's a dermatologist at Lenox Hill Hospital in New York City.
The new study was led by Dr. Megha Tollefson, of the department of dermatology at the Mayo Clinic in Rochester, Minn. Her team looked at federal government data on more than 3,400 U.S. adults averaging about 40 years of age who'd completed questionnaires detailing their sun-protective behaviors.
Nearly 32% of the participants said they frequently sought out shade, around 12% said they intentionally wore long sleeves and about 26% used sunscreen — all to help avoid skin cancers, the findings showed.
Tollefson's team then looked at data on all of the study participants' bone mineral density tests and any history of bone fractures that might be linked to osteoporosis.
The study could find no significant association between sun-protective behaviors and bone mineral density, and "there was no increased risk of osteoporotic bone fractures," either.
The findings are important, the study authors said, because the myth that sunscreen will deplete the body of bone-building vitamin D remains widespread.
"Despite the lack of established data to support negative associations of sun protection with vitamin D status and bone health, many patients may still be reluctant to use sunscreen because, in their own words, 'I don't want to become vitamin D-deficient,'" Tollefson's group reported.
The researchers believe the new study helps further the "sun-protective conversation" around these myths.
The study was published online recently in JAMA Dermatology.