The effects of regular tanning bed use and increased vitamin D status on bone mineral density and serum inflammatory markers in healthy women

Abstract

Vitamin D is synthesized in the skin in response to UVB radiation and has an essential function in optimal bone health. Recent evidence has also implicated a role for vitamin D in a properly functioning immune system. The objective of this study was to determine the relationship between vitamin D status, inflammatory markers, and bone mineral density in healthy pre- and post-menopausal women who regularly use tanning beds. This observational study examined 69 healthy female subjects: 49 Tanners and 20 Non-Tanners. Subjects provided medical and dietary information, a blood specimen, and bone mineral density was measured. Blood specimens were analyzed for serum 25(OH)D, parathyroid hormone (iPTH), estradiol (E2), cortisol, and inflammatory markers. Results: Tanners had serum 25(OH)D concentrations that were significantly higher (P[lesser than]0.0001) and iPTH concentrations that were significantly lower (P[lesser than]0.0001) than Non-Tanners. There were no differences in bone density between groups. Tanners had significantly lower serum TNF[alpha] (P[lesser than]0.0200) and a linear regression revealed that 25(OH)D had a significant inverse relationship with TNF[alpha] (P[lesser than]0.0463), which remained significant after controlling for potential covariates. Conclusions: Serum 25(OH)D status is inversely related to TNF[alpha] concentrations in healthy women, which may in part explain its role in the prevention and treatment of numerous diseases.