AT A GLANCE

A randomized pilot study found that four brief UV sessions significantly increased serum vitamin D levels without triggering notable inflammatory responses or skin damage. The results suggest controlled UVR could offer a safe, non-oral strategy to improve vitamin D status in select patients.

A new pilot trial offers encouraging insights into the controlled use of ultraviolet radiation (UVR) as a means to safely improve vitamin D status in deficient adults—without provoking inflammation. Researchers conducted a randomized study in 24 healthy volunteers, administering four short, standardized UV exposures to representative skin areas. Blood samples collected throughout the trial revealed a significant rise in serum vitamin D levels, coupled with declines in calcium, phosphorus, and parathyroid hormone, all indicating a physiological response to improved vitamin D synthesis.

Importantly, while markers of oxidative stress (notably reactive oxygen species) increased, the study found no significant changes in inflammatory markers such as C-reactive protein, nitric oxide, or key cytokines including IL-6 and TNF-α. Skin assessments showed no visible adverse effects, suggesting that brief UVR exposure may be a viable strategy to support vitamin D production in a controlled, low-risk setting.

"Our findings demonstrate that UVR exposure can enhance vitamin D synthesis in healthy adults without significant inflammatory responses or adverse effects," report the authors, "providing a basis for optimizing UV-based interventions to improve vitamin D status through risk management."

Mo C, Bajgai J, Rahman MH, et al. A pilot clinical trial to explore the effects of UV exposure on vitamin D synthesis and inflammatory responses in vitamin D-Deficient adults. Sci Rep. 2025;15(1):22557. Published 2025 Jul 2. doi:10.1038/s41598-025-09203-8