Sun-protective behavior does not affect osteoporotic health, bone density

Avoiding the sun and practicing sun-protective behaviors does not show an association with osteoporotic fractures or reduced bone density, according to a study.

“The use of sunscreen and other sun-protective measures is clinically recommended for risk reduction of melanoma and nonmelanomatous skin cancers and for accelerated skin-aging prevention,” Mohsen Afarideh, MD, MPH, of the department of dermatology at the Mayo Clinic in Rochester, Minnesota, and colleagues wrote. “Given that the UV irradiation range (approximately 290-320 nm) to induce effective vitamin D photosynthesis is within the photocarcinogenic UV-B spectrum, a potential concern for the use of sunscreens and other sun-protective measures to induce vitamin D deficiency has arisen among both the medical and lay communities.”

A population-based cross-sectional study using data from the 2017-2018 National Health and Nutrition Examination Survey (NHANES) was conducted to evaluate how sun-protective behaviors may be associated with osteoporotic fractures and bone mineral density (BMD).

Sun-protective behaviors were described as staying in the shade, wearing long sleeves and sunscreen use.

Responses from 3,403 adults who completed all three of the sun-protection components of the NHANES dermatology questionnaire were included in the analysis.

Of this group, the prevalence of sun-protective behaviors was 31.6% (95% CI, 27.8%-35.7%) for staying in the shade, 11.8% (95% CI, 10.6%-13.1%) for wearing long sleeves, and 26.1% (95% CI, 23.5%-28.8%) for sunscreen use.

Diminished site-specific and total bone mineral density z scores were measured using a dual X-ray absorptiometry technique.

Multivariate models showed BMD z scores were not associated with sun-protective behaviors. In addition, a reduced prevalence of spine fractures was found in the multivariate model with those who stayed in the shade moderately or frequently (OR = 0.19; 95% CI, 0.04-0.86; P = .02).

“Results of this cross-sectional study demonstrated that the continued practice of sun protection is not associated with increased bone-related health complications such as decreased BMD and/or increased osteoporotic fractures,” the authors wrote.