Ultraviolet B Light Emitting Diodes (LEDs) Are More Efficient and Effective in Producing Vitamin D3 in Human Skin Compared to Natural Sunlight

Abstract

Vitamin D, the sunshine vitamin is important for health. Those with fat malabsorption disorders malabsorb vitamin D and thus must rely on cutaneous production of vitamin D3. Vitamin D3 is generated secondary to exposure to ultraviolet B (UVB) radiation (whether from the sun or from an artificial source). Light emitting diodes (LEDs) have been developed to emit ultraviolet radiation. Little is known about the efficiency of UVB emitting LEDs tuned to different wavelengths for producing vitamin D3 in human skin. Ampoules containing 7-dehydrocholesterol were exposed to a LED that emitted a peak wavelength at 293, 295, 298 or 305 nm to determine their efficiency to produce previtamin D3. The 293 nm LED was best suited for evaluating its effectiveness for producing vitamin D in human skin due to the shorter exposure time. This LED was found to be 2.4 times more efficient in producing vitamin D3 in human skin than the sun in less than 1/60th the time. This has significant health implications for medical device development in the future that can be used for providing vitamin D supplementation to patients with fat malabsorption syndromes as well as patients with other metabolic abnormalities including patients with chronic kidney disease.

13 mW operation of a 295–310 nm AlGaN UV-B LED with a p-AlGaN transparent contact layer for real world applications

“…One important result in the application of UV-B LEDs came from Boston University in the USA, where it was discovered that a UV-B LED with an emission wavelength of 293 nm is 2.4 times more efficient than sunlight for producing vitamin D3 in human skin. 18 But, the light extraction efficiency (LEE) was found to be very low in the p-GaN based UV-B LED devices due to the light absorption by p-GaN. 6,27 In this work, we successfully achieve more than 97% transmittance from the p-AlGaN contact layer with the UV-B LED, as shown in Fig.…”

“…One important result in the application of UV-B LEDs came from Boston University in the USA, where it was discovered that a UV-B LED with an emission wavelength of 293 nm is 2.4 times more efficient than sunlight for producing vitamin D3 in the human body. 18 Based on this comparative review study of UV-B light sources, we picked out two important UV-B-wavelength emission applications between 294 nm and 310 nm. Therefore, we began our research and development of UV-B LED devices here at Riken, with medical science (294-310 nm) and agricultural applications (310 nm) in mind, in 2017.…”

Site‐Specific Encoding of Photoactivity in Antibodies Enables Light‐Mediated Antibody–Antigen Binding on Live Cells

“…UV light is also being used clinically in combination with the drug, psoralen, for treatment of skin cancer . LEDs emitting UV light are under investigation for treatment of Vitamin D deficiency, and, there have been investigations on activation of antibody‐based drugs using UV radiations, for treatment of ovarian cancer in mice models . The extension of the present work towards utilizing near‐infrared (IR) radiation instead of UV, is expected to widen its applicability as IR radiation penetrates deeper into tissue.…”

Influence of Undoped‐AlGaN Final Barrier of MQWs on the Performance of Lateral‐Type UVB LEDs

“…Last but not the least, the ultimate goal is to develop NB‐UVB LED light sources, which are strongly needed for the specific real‐world applications, such as those in immunotherapy, for vulgaris treatment, and plant lightning . A small part of the NB‐UVB spectrum can be used to treat skin conditions such as psoriasis and eczema .…”

“…Low cost, smart, safe, and low power consumption aluminium gallium nitride (AlGaN)‐based ultraviolet‐B light‐emitting diodes (UVB LEDs), compared with the other UV light sources including toxic mercury UV‐Lamps, are needed for real‐world applications, such as those in immunotherapy (psoriasis, vitiligo), vulgaris treatment, plant growth under UVB lightning, the production of vitamin D 3 in the human body, and the production of phytochemicals in green leaves of vegetables . Based on these motivations, we began our research and development of AlGaN‐based UVB LED devices to be grown on aluminum nitride (AlN) template, with medical science (294–310 nm) as well as agricultural applications (310 nm) in mind . However, the existence of high threading dislocation densities (TDDs ≈10 10 cm −2 ) in the AlGaN buffer layer (BL) grown on sapphire substrate, which is caused by large lattice mismatch ≈16% at the interface of sapphire substrate and BL, have presented a big challenge for many researchers .…”