Evaluation of a Ultraviolet B Light Emitting Diode (LED) for Producing Vitamin D₃ in Human Skin

Abstract

Aim: A commercially available light emitting diode (LED) that transmitted narrow band ultraviolet B (UVB) radiation was evaluated for its efficacy and efficiency to produce vitamin D 3 in human skin. Materials and Methods: Human skin samples were obtained from surgical procedures. The LED had peak emission wavelength of 295 nm. Skin samples were exposed to the UVB-LED for varying times and then were analyzed by high-pressure liquid chromatography (HPLC) to determine the vitamin D 3 content. Results: There was a statistically significant time-and dosedependent increase in the percent of 7-dehydrocholesterol that was converted to vitamin D 3 in the skin type II samples; 1. 3%±0.5, 2.3%±0.6 and 4.5%±1.67 after exposure to 0.75 (11.7 mJ/cm 2 ), 1.5 (23.4 mJ/cm 2 ) and 3 (46.8 mJ/cm 2 ) minimal erythemal doses (MEDs), respectively. Conclusion: The UVB-LED was effective and efficient in generating vitamin D 3 in human skin, in vitro. The amount of vitamin D 3 production increased in a dose-dependent fashion with increased UVB energy. UVB-LEDs can be developed for devices that can efficiently produce vitamin D 3 in human skin.Vitamin D is mainly obtained from sun exposure, as well as from few dietary sources (1, 2). Specifically, during sun exposure, epidermal 7-dehydrocholesterol (7-DHC or provitamin D 3 ) absorbs solar ultraviolet (UV) B radiation, which results in the thermodynamically unstable molecule, previtamin D 3 . Once formed, the triene system in previtamin D 3 rearranges to form the more thermodynamically stable product, vitamin D 3 (1-4). After its formation, vitamin D 3 enters the circulation from the skin and is transported to the liver to be metabolized into 25-hydroxyvitamin D 3 (25(OH)D), and to the kidneys to undergo additional metabolism to 1,25-dihydroxyvitamin D 3 (1, 3, 5-7).The Sperti lamp, which contained a mercury arc lamp, was produced in the 1940s in the United States, where it was available in pharmacies to treat and prevent the bone disorder known as rickets (1, 6, 7). Since then, there has been an evolution of improved, more user-friendly vitamin D-producing devices for the treatment and prevention of vitamin D deficiency. In particular, the modern version of the Sperti lamp, Sperti D/UV-Fluorescent lamp (KBD, Inc., Las Vegas, NV, USA), was designed with UVB emitting fluorescent bulbs, which have the benefit of a lower heat emission than the previously mercury arc lamps. Additionally, these new UVB-emitting bulbs allow for a larger area of the user's skin to be exposed (8-10). Indeed, the Sperti D/UV-Fluorescent lamp has been shown to be effective in raising blood levels of 25(OH)D in healthy adults, as well as in patients with fat malabsorption syndromes who may not benefit from oral vitamin D supplementation (8,9).The modern version of the Sperti lamp includes improved gallium nitride-based UV light-emitting diode (LED), and is commercially available for use in clinical application (11,12). These LEDs can also be designed to emit specific UV narrow band in order to be utilized therapeu...

Low dose ultraviolet B irradiation at 308 nm with light-emitting diode device effectively increases serum levels of 25(OH)D

“…An accumulated dosage of 355 mJ/cm 2 UVB irradiation is estimated to normalize 25(OH)D level at approximately 30 ng/mL from severe VDd at 3 week. Several studies used either low-dose or/and narrow-band UVB for VDd improvement 23,24,29,30 ; but ours is the first one to demonstrate, with the center of wavelength at 308 nm, could normalize severe VDd. Narrow band UVB, first utilized as phototherapy for psoriasis, was previously shown, just as sunlight and broad band UVB, to be able to increase 25(OH)D. Since then, several studies investigated the effect of different wavelengths of UVB on VDd improvement, and it is now clear that wavelength affects cutaneous vitamin D synthesis in a hill distribution with the peak efficiency at 300 nm over the UVB wavelength spectrum 27,28 .…”

“…Veronikis A.J. et al in their recent study discovered that UVB-LED with the wavelength of 295 nm and irradiation of 117, 234, and 468 J/m 2 were effective at generating vitamin D3 in human skin in vitro with a dose-response 23 . Our results further proved, even with less biological effect on vitamin D synthesis, UVB 308 nm of lower irradiation less than 1 SED (100 J/m 2 ) can normalize the VDd.…”

“…Considering the general lack of compliance of taking vitamin D supplements and in order to avoid oral vitamin D toxicity due to over-dosage, UV lamps, as a component of home lighting, could constitute a viable alternative to overcome common VDd 22 . Effectiveness of vitamin D synthesis, and adverse effects such as carcinogenesis, erythema injury, and DNA damage are mainly determined by spectrum of UVB 23,24 that should be carefully considered in developing UV lamps.…”

Analysis of Photosynthetic Systems and Their Applications with Mathematical and Computational Models

“…The feasibility and potential of such studies can be attributed to the fact that light harvesting antennas like chlorosomes have a special structure through which they can absorb light even from the region with very low intensity of light source. The previtamin D3 from 7-dehydrochlorostel level can also be determined in human skin by studying photosynthesis in them through exposure to sunlight [219,220]. The photosynthetic bacteria are also a good source of vitamin B12 and have been used in some of the important medical applications, including the treatment of anemia, neuritis and eye problems [124].…”

Very Low-Efficiency Droop in 293 nm AlGaN-Based Light-Emitting Diodes Featuring a Subtly Designed p-Type Layer

“…For example, DUV-LEDs are suitable for the production of vitamin D 3 . In human skin, vitamin D 3 production depends on several factors, including the person’s age, the time of day, the latitude and altitude, the season, the area of exposure, and the degree of skin pigmentation, with ultraviolet-B (UVB) wavelengths between 290 and 300 nm being most efficient [ 7 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Kalajian et al [ 14 ] found that light at a wavelength of 293 nm was 2.4 times more efficient at producing vitamin D 3 in human skin than light from the sun was, as measured according to the exposure time.…”