% Conversion UV LED % Conversion of Pro

Novel Use of an Ultraviolet Emitting LED for Producing
Vitamin D3 in Human Skin
Benjamin Nelson BA, Michael F. Holick PhD MD
Department of Medicine, Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine
Introduction
Results
Vitamin D deficiency continues to be a major issue globally. In addition,
patients with fat malabsorption syndromes and patients after gastric
bypass surgery often are unable to absorb vitamin D either from their diet
or from supplements. There continues to be a need to find a safe
alternative by harnessing the human skin’s natural ability to produce
vitamin D after solar ultraviolet radiation (UV) exposure.
Four different skin types were irradiated with the UV LED for 10 minutes. Using
the Fitzpatrick Scale of skin classification, they were classified as skin types II, IV,
V, and VI. Each of the skin types exposed to LED UV radiation made vitamin D
(Figure 2 and Figure 4). The control skin pieces (un-irradiated with UV LED) did
not make any vitamin D. Skin types IV and V, when exposed for 10 and 20
minutes demonstrated a time dependent increase in the production of vitamin D
(Figure 2). A sample of skin type VI was also placed in direct sunlight at midday
in July for 1 hour and generated as much vitamin D as a skin sample under LED
UV radiation for 10 minutes (Figure 2).
Our project investigated the efficiency and effectiveness of this novel LED
UV emitting radiation source in producing vitamin D in surgically obtained
human skin samples from subjects of all skin types. Ultimately,
commercialization of an easily portable LED UV source to produce vitamin
D in the skin for people with fat malabsorption syndromes could provide
an invaluable tool to combat vitamin D deficiency in this vulnerable
population.
B
UV LED % Conversion of ProVitamin D to Vitamin D in Human
Skin
B
1.2
C
1
% Conversion
Currently, there are 2 commercially available light sources (mercury arc
and fluorescent bulbs) capable of producing vitamin D in the skin. Both of
these devices are somewhat cumbersome and generate a significant
amount of heat. Dr. Moustakas’s laboratory recently developed an LED
light that emits broad spectrum UV radiation, including the spectrum
responsible for making Vitamin D in the skin.
A
% Conv. Skin Type V
0.8
% Conv. Skin Type II
% Conv. Skin Type IV
0.6
% Conv. Skin Type VI
D
0.4
0.2
0
10 min LED 20 min LED
Control
1 Hr (Roof)
Figure 4. High Performance Liquid Chromatography (HPLC) chromatograms of skin
types V (A), VI (B), IV (C), and II (D) after irradiation for 10 minutes of LED UV
radiation. Vitamin D peaks are marked with the red dot.
Figure 2. % Conversion of pro-vitamin D to vitamin D with varying times of irradiation by the
UV LED.
A
C
Figure 1. A) The UV LED. B) UV LED without a skin sample. C) UV LED irradiating a
skin sample from below.
Methods
1.
2.
3.
4.
5.
Irradiate human skin samples obtained from plastic surgical procedures
with LED UV radiation for 10 and 20 minutes
One sample from skin type VI was also placed on the roof under direct
sunlight at midday in July
Remove the epidermis from the skin sample
Extract the epidermis with 8% ethyl acetate in hexane
Measure the vitamin D content using High Performance Liquid
Chromatography
Conclusion
References
Preliminary data on the use of a UV LED to produce vitamin D in human
epidermis is very promising. Our data shows that human skin exposed to
the UV LED produces vitamin D and there was a time dependent increase
in the production of vitamin D. Our data also suggest that 10 minutes
under the UV LED is equivalent to 1 hour of sun exposure at noontime in
July. These results indicate that it would be possible to create a wearable
light source to combat vitamin D deficiency, especially in people with fat
malabsorption syndromes.
1. MacLaughlin JA, Anderson RR, Holick MF. Spectral character of sunlight modulates the
photosynthesis of previtamin D3 and its photoisomers in human skin. Science. 1982. 10011003.
2. Chandra, P., Wolfenden, L.L., Ziegler, T.R., Tian, J., Luo, M., Stecenko, A.A., Chen, T.C., Holick,
M.F., and Tangpricha, V. Treatment of Vitamin D Deficiency with UV Light in Patients with
Malabsorption Syndromes: A Case Series. Photochem Photobiol. 2007. 23(5):179-85.
3. Holick, M.F., Chen, T.C., Sauter, E.R. Vitamin D and Skin Physiology: A D-Lightful Story. J Bone
Miner Res. 2007. 22(S2):V28-V33.
4. Dabai, NS, Pramyothin, P and Holick, MF. The Effect of Ultraviolet Radiation from a Novel
Portable Flourescent Lamp on Serum 25-Hydroxyvitamin D3 Levels in Healthy Adults with
Fitzpatrick Skin Types II and III. Photodermatol Photoimmunol Photomed. 2012. 28(6):307-311.
Thanks
Mentors: Michael F. Holick PhD MD
Labmates/Colleagues: Milan Minsky PhD, Theodore Moustakas PhD, Kelly
Persons, Keshav Thvar, Ruchi Jain, Sophia Xiao, Tiffany Shih
Funding for this project was provided through the Medical Student Summer
Research Program at Boston University School of Medicine
Figure 3. Prototype of a wearable UV LED to produce vitamin D in human skin.

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