Long-term ultraviolet B irradiation at 297 nm with light-emitting diode improves bone health via vitamin D regulation

Biomed Opt Express. 2024 Jun 4;15(7):4081-4100. doi: 10.1364/BOE.520348. eCollection 2024 Jul 1.

Abstract

Ultraviolet radiation is the primary determinant for vitamin D synthesis. Sunlight is inefficient and poses a risk, particularly for long-term exposure. In this study, we screened the most favorable wavelength for vitamin D synthesis among four types of narrowband light-emitting diodes (LEDs) and then irradiated osteoporosis rats with the optimal wavelength for 3-12 months. The 297 nm narrowband LED was the most efficient. Long-term radiation increased vitamin D levels in all osteoporotic rats and improved bone health. No skin damage was observed during irradiation. Our findings provide an efficient and safe method of vitamin D supplementation.