Osteoporosis is a bone disease associated with aging. As the population ages, osteoporosis has become a significant public health problem that threaten life quality of most countries in the world. Adequate vitamin D is able to improve intestinal calcium absorption, promote bone mineralization, maintain muscle strength, enhance balancing ability, and reduce fall risks, whichplays a vital role in bone metabolism. Moreover, vitamin D is mainly produced by ultraviolet (UV) light. The serum levels of 25(OH)D3 is the tools for estimating of the osteoporosis.It is known that vitamin D deficiency is ubiquitous in the elderly population, hence, we adopted UV light-emitting diode (UV-LED) instruments to generate narrow-range wavelengths of UV and determined its capability for producing vitamin D. The osteoporosis SD rats are our research subjects. The study was to investigate the effects of UV-LEDs of different power densities on vitamin D production. There are 4 groups：0.1, 0.2, 0.4, 0.8mW/cm2 and the rats (n = 6 per group) were irradiated with different power densities twice a week for a total of 8 weeks. The results showed that serum 25(OH)D3 levels rapidly increased in all irradiated groups compared with those in the control group (P < 0.001 in all groups), and 25(OH)D3 level of the rats in groups of both 0.4 and 0.8 m W/cm2 were able to return to the initial level at the fourth week after irradiation, besides, the group of 0.4 mW/ W/cm2 can achieve and maintain the highest25(OH)D3 level and so as the group of 0.8 m W/cm2 as the continuing irradiation. We demonstrate that the proper irradiation density of UV-LED irradiation can increase the production of vitamin D in rats and does not adversely affect the skin of rats.
Osteoporosis (OP) is a systemic bone disease in which the bone mass reduce, the microstructure of the bone degenerate, and the bone fragility increase, which would be prone to fracture. In the light of the aging society, the incidence of osteoporosis is increasing year by year. At present, the mainstream treatment is using drugs. Although drugs have certain therapeutic effect on osteoporosis, it require long-term medication and will arise different adverse reactions. Low-level laser therapy (LLLT) is an emerging treatment in recent years. It is the application of a coherent or incoherent low-intensity laser, usually in the infrared to near-infrared 630-1000nm wavelength range, to the lesion tissue or monolayer cells to cause non-destructive and non-thermal biological reactions for therapeutic purposes. It is a physical therapy for therapeutic purposes. Studies have shown that low-level laser therapy can activate osteoblasts, promote bone repair, enhance the bone structure of peri-menopausal rat models, and increase bone density, which can be used as an effective intervention for osteoporosis in middle-aged and elderly women. This article reviews recent advances in the study of low-level laser treatment of osteoporosis.