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1) UV Light especially UVB (280-400 nm) - Important for vitamin D synthesis.
It is common knowledge that exposure to sunlight increases vitamin D production in the body, specifically its UVB wavelengths. Vitamin D is not only beneficial for strong bones and enhanced immunity, but also helps prevent countless diseases, including prostate, breast, colon, and ovarian cancers, multiple sclerosis, high blood pressure, osteoporosis, psoriasis, seasonal affective disorder, diabetes (both type I and II), autoimmune thyroid disorders, lupus and even tooth decay and schizophrenia. That’s quite a list of maladies. Imagine building armor against all of those just by going outside! No over the counter vitamin D supplement can rival natural sunlight. Best of all – take that, corporate America - it’s free! Besides stimulating Vitamin D synthesis, UV light of all wavelengths is a strong antibiotic, antiviral, anti-fungal and disinfectant, which helps protect the body from viruses, bacteria, mold and fungus from our environment.
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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.
The beneficial role of ultraviolet radiation on bone health began in 1919 when Huldschinsky reported that children who were exposed to a mercury arc lamp showed significant radiologic improvement of their rickets several months later. He noted that exposure to one forearm of a child with rickets displayed the same radiologic improvements in the other arm not exposed to the mercury arc lamp [1]. He concluded that something was produced in the skin that entered the circulation causing widespread improvements in bone mineralization in children with rickets. The connection with sunlight was made when Hess [2] exposed rachitic children to the sun in New York City from half an hour to several hours and reported significant improvements in their rickets [2].
It is now recognized that during exposure to sunlight, ultraviolet B (UVB) radiation between 290–315 nm penetrates into the skin and is absorbed by 7-dehydrocholesterol (7-DHC) [3-5]is results in the cleavage of certain bonds to create a "previtamin" D3. Once formed, previtamin D3 is thermodynamically unstable, and rearranges into a more thermodynamically stable form, vitamin D3
Vitamin D3 production in human skin depends on several factors. The size of the area exposed to UV radiation is directly proportional to the amount of vitamin D3 produced; the larger the area exposed, the more vitamin D3 is produced. For example, sunbathing in a swimsuit can produce an amount of vitamin D3 similar to ingesting ~ 20,000 IU of vitamin D [1,11]. Aging, skin pigmentation, sunscreen use, time of day, latitude, season, and altitude are other factors that affect this vital cutaneous process [1,6,8,10,11]
Tanning beds that emit UVB radiation produce vitamin D3 14. Exposure to tanning bed radiation raised blood levels of 25(OH)D in a patient with Crohn’s disease who was unable to absorbed dietary or supplemental vitamin D3 15. Patients with fat malabsorption syndromes including those with inflammatory bowel disease, cystic fibrosis and gastric bypass surgery are at high risk for vitamin D3 deficiency and are in need of a user friendly device that can promote the cutaneous production of vitamin D3 8, 16.
Therefore, LEDs would offer an alternative efficient way of providing the user with a defined suberythemal amount of UVB radiation for producing their vitamin D requirement. These LEDs can also be developed for treating and preventing recurrent vitamin D deficiency in patients who are unable to absorb vitamin D through their gastrointestinal tract due to fat malabsorption syndromes15. Another use could be in patients with chronic kidney disease. It was observed that patients with end-stage chronic kidney disease who were exposed to UVB radiation were able to improve their vitamin D status as well as increase their blood levels of 1,25-dihydroxyvitamin D3 and decrease their parathyroid hormone levels thereby improving their calcium and bone metabolism26. In addition, these patients required less erythropoietin to maintain their blood hematocrit and had significant improvement in their cardiovascular status26.
[1] Wacker M, Holick MF. Sunlight and Vitamin D: A global perspective for health. Dermatoendocrinol. 2013;5:51–108.
[2] Hess AF, Ungerm LJ. The cure of infantile rickets by artificial light and by sunlight. Exp Biol Med. 2016;18(8):298
It is common knowledge that exposure to sunlight increases vitamin D production in the body, specifically its UVB wavelengths. Vitamin D is not only beneficial for strong bones and enhanced immunity, but also helps prevent countless diseases, including prostate, breast, colon, and ovarian cancers, multiple sclerosis, high blood pressure, osteoporosis, psoriasis, seasonal affective disorder, diabetes (both type I and II), autoimmune thyroid disorders, lupus and even tooth decay and schizophrenia. That’s quite a list of maladies. Imagine building armor against all of those just by going outside! No over the counter vitamin D supplement can rival natural sunlight. Best of all – take that, corporate America - it’s free! Besides stimulating Vitamin D synthesis, UV light of all wavelengths is a strong antibiotic, antiviral, anti-fungal and disinfectant, which helps protect the body from viruses, bacteria, mold and fungus from our environment.
Add in
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.
The beneficial role of ultraviolet radiation on bone health began in 1919 when Huldschinsky reported that children who were exposed to a mercury arc lamp showed significant radiologic improvement of their rickets several months later. He noted that exposure to one forearm of a child with rickets displayed the same radiologic improvements in the other arm not exposed to the mercury arc lamp [1]. He concluded that something was produced in the skin that entered the circulation causing widespread improvements in bone mineralization in children with rickets. The connection with sunlight was made when Hess [2] exposed rachitic children to the sun in New York City from half an hour to several hours and reported significant improvements in their rickets [2].
It is now recognized that during exposure to sunlight, ultraviolet B (UVB) radiation between 290–315 nm penetrates into the skin and is absorbed by 7-dehydrocholesterol (7-DHC) [3-5]is results in the cleavage of certain bonds to create a "previtamin" D3. Once formed, previtamin D3 is thermodynamically unstable, and rearranges into a more thermodynamically stable form, vitamin D3
Vitamin D3 production in human skin depends on several factors. The size of the area exposed to UV radiation is directly proportional to the amount of vitamin D3 produced; the larger the area exposed, the more vitamin D3 is produced. For example, sunbathing in a swimsuit can produce an amount of vitamin D3 similar to ingesting ~ 20,000 IU of vitamin D [1,11]. Aging, skin pigmentation, sunscreen use, time of day, latitude, season, and altitude are other factors that affect this vital cutaneous process [1,6,8,10,11]
Tanning beds that emit UVB radiation produce vitamin D3 14. Exposure to tanning bed radiation raised blood levels of 25(OH)D in a patient with Crohn’s disease who was unable to absorbed dietary or supplemental vitamin D3 15. Patients with fat malabsorption syndromes including those with inflammatory bowel disease, cystic fibrosis and gastric bypass surgery are at high risk for vitamin D3 deficiency and are in need of a user friendly device that can promote the cutaneous production of vitamin D3 8, 16.
Therefore, LEDs would offer an alternative efficient way of providing the user with a defined suberythemal amount of UVB radiation for producing their vitamin D requirement. These LEDs can also be developed for treating and preventing recurrent vitamin D deficiency in patients who are unable to absorb vitamin D through their gastrointestinal tract due to fat malabsorption syndromes15. Another use could be in patients with chronic kidney disease. It was observed that patients with end-stage chronic kidney disease who were exposed to UVB radiation were able to improve their vitamin D status as well as increase their blood levels of 1,25-dihydroxyvitamin D3 and decrease their parathyroid hormone levels thereby improving their calcium and bone metabolism26. In addition, these patients required less erythropoietin to maintain their blood hematocrit and had significant improvement in their cardiovascular status26.
[1] Wacker M, Holick MF. Sunlight and Vitamin D: A global perspective for health. Dermatoendocrinol. 2013;5:51–108.
[2] Hess AF, Ungerm LJ. The cure of infantile rickets by artificial light and by sunlight. Exp Biol Med. 2016;18(8):298
Lighter Fitzpatrick skin types (I and II) produce vitamin D more efficiently from sunlight than darker types (IV, V, and VI) because they have less melanin, which absorbs UV radiation and reduces vitamin D synthesis.
Simplying the studies, darker Type IV-VI skin types need 2-3 times the sunlight exposure to get the same Vitamin D synthesis as lighter type I and II skin types.
Dosage Issues Fitzpatrick Skin Types
NBUVB radiation dosages to elicit a response were .390, .550, .770, and .885 mJ/cm2 for the 4 Type I-IV skin types. The main thing is the ratios (Type IV .885 is a little more than double Type I). minimal erythema dose (MED), which is defined as the dose of UV-B radiation that produces perceptible erythema 24hours after administration.
Pérez-Ferriols A. Proyecto dosis eritematosa mínima (DEM): en busca del consenso en la técnica del fototest. Actas Dermosifiliogr. 2013;104:541–2.
Erythema (air-uh-theem-uh) refers to abnormal redness of the skin or mucous membranes, typically caused by capillary congestion or inflammation. which includes sunburns.
Simplying the studies, darker Type IV-VI skin types need 2-3 times the sunlight exposure to get the same Vitamin D synthesis as lighter type I and II skin types.
Dosage Issues Fitzpatrick Skin Types
NBUVB radiation dosages to elicit a response were .390, .550, .770, and .885 mJ/cm2 for the 4 Type I-IV skin types. The main thing is the ratios (Type IV .885 is a little more than double Type I). minimal erythema dose (MED), which is defined as the dose of UV-B radiation that produces perceptible erythema 24hours after administration.
Pérez-Ferriols A. Proyecto dosis eritematosa mínima (DEM): en busca del consenso en la técnica del fototest. Actas Dermosifiliogr. 2013;104:541–2.
Erythema (air-uh-theem-uh) refers to abnormal redness of the skin or mucous membranes, typically caused by capillary congestion or inflammation. which includes sunburns.
Main Article
https://pmc.ncbi.nlm.nih.gov/articles/PMC5597604/
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.
Vitamin D 32.15 min Sun = 15,300 IU
Vitamin D 31.2 secs 293nm LED = 39,100 IU
RDA = 600 IU
Assuming an average adult body surface area 1.7 m^2 [21], a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
We found that the 293 nm LED, provided by Rayvio, was best suited for human trials due to a more than 50% shorter exposure time to produce the same amount of vitamin D3 as the other LEDs.
31.2 seconds * ________ = .0468 J/cm^2
.52 Minutes
1.5 mW/cm^2
Sun UVB irradiance .06 to .35 mW/cm^2
UV like only 3% total solar irradiance
v=ir = .5 Watt Bulb (50 Volts * 10 mAMP
Solarmeter to calculate the exposure time needed for each LED to reach 46.8 mJ/cm2 (equivalent to 3 MEDs).
.05 Watt bulb
The LEDs were powered with a power supply (supplied by RayVio) set to 50 V and 10 mA for all the experiments. The energy output of each LED was measured using a UVB meter, Solarmeter (Solar Light Company, Inc, Glenside, PA).
UV wavelengths between 290–300 nm were found to be the most efficient for vitamin D3 production in human skin and human skin equivalent models 4, 5. With the advancement of gallium nitride LED (Light Emitting Diode) technology that emits UV radiation, it is now possible to manufacture LEDs that are efficient and suitable for a wide range of commercial uses
This LED was also found to be 2.4 and 2.5 times more efficient in producing vitamin D3 in Type II and Type III human skin respectively compared to being exposed to the same amount of energy from the sun in a much shorter time. For example the suberythemal exposure of the skin type II to 0.75 MED from the 293 LED produced 2.3 IUs cm2 (5.63 ng/cm2) in one half minute compared to a less than half the amount (0.9 IUs; 2.35 ng/cm2) vitamin D3 when the same skin sample was exposed to the sun for more than 60 times longer time (32.15 min). Assuming an average adult body surface area 1.7 m2 21, a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
Assuming an average adult body surface area 1.7 m^2 [21], a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
However, prolonged exposure to UV radiation from the sun increases the risk for non-melanoma skin cancer27. This occurs mainly due to DNA damage from wavelengths that are absorbed by DNA that lead to the formation of DNA damage products including cyclobutane pyrimidine dimers (CPD)27,28.
Although the 305 nm would have been thought to be the most desired due to its lower energy, because of the marked decrease in quantum efficiency, there was a more than 10 fold decrease in the production of previtamin D3 compared to the other LEDs. It would likely require 10 times more 305 nm photons to generate the same amount of previtamin D3 as the 293 nm LED. Therefore another advantage of the 293 nm LED may be reduced risk of skin damage when compared to exposure to sunlight or the 305 nm LED.
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https://pmc.ncbi.nlm.nih.gov/articles/PMC5597604/
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.
Vitamin D 32.15 min Sun = 15,300 IU
Vitamin D 31.2 secs 293nm LED = 39,100 IU
RDA = 600 IU
Assuming an average adult body surface area 1.7 m^2 [21], a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
We found that the 293 nm LED, provided by Rayvio, was best suited for human trials due to a more than 50% shorter exposure time to produce the same amount of vitamin D3 as the other LEDs.
31.2 seconds * ________ = .0468 J/cm^2
.52 Minutes
1.5 mW/cm^2
Sun UVB irradiance .06 to .35 mW/cm^2
UV like only 3% total solar irradiance
v=ir = .5 Watt Bulb (50 Volts * 10 mAMP
Solarmeter to calculate the exposure time needed for each LED to reach 46.8 mJ/cm2 (equivalent to 3 MEDs).
.05 Watt bulb
The LEDs were powered with a power supply (supplied by RayVio) set to 50 V and 10 mA for all the experiments. The energy output of each LED was measured using a UVB meter, Solarmeter (Solar Light Company, Inc, Glenside, PA).
UV wavelengths between 290–300 nm were found to be the most efficient for vitamin D3 production in human skin and human skin equivalent models 4, 5. With the advancement of gallium nitride LED (Light Emitting Diode) technology that emits UV radiation, it is now possible to manufacture LEDs that are efficient and suitable for a wide range of commercial uses
This LED was also found to be 2.4 and 2.5 times more efficient in producing vitamin D3 in Type II and Type III human skin respectively compared to being exposed to the same amount of energy from the sun in a much shorter time. For example the suberythemal exposure of the skin type II to 0.75 MED from the 293 LED produced 2.3 IUs cm2 (5.63 ng/cm2) in one half minute compared to a less than half the amount (0.9 IUs; 2.35 ng/cm2) vitamin D3 when the same skin sample was exposed to the sun for more than 60 times longer time (32.15 min). Assuming an average adult body surface area 1.7 m2 21, a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
Assuming an average adult body surface area 1.7 m^2 [21], a 0.75 MED exposure of the whole body to the 293 nm LED would generate 39,100 IUs.
However, prolonged exposure to UV radiation from the sun increases the risk for non-melanoma skin cancer27. This occurs mainly due to DNA damage from wavelengths that are absorbed by DNA that lead to the formation of DNA damage products including cyclobutane pyrimidine dimers (CPD)27,28.
Although the 305 nm would have been thought to be the most desired due to its lower energy, because of the marked decrease in quantum efficiency, there was a more than 10 fold decrease in the production of previtamin D3 compared to the other LEDs. It would likely require 10 times more 305 nm photons to generate the same amount of previtamin D3 as the 293 nm LED. Therefore another advantage of the 293 nm LED may be reduced risk of skin damage when compared to exposure to sunlight or the 305 nm LED.
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