# Need advice building blue LED device for treatment of Seasonal Affective Disorder



## SciGuy (Dec 29, 2009)

After many years battling the depression and sleep distubance of Seasonal Affective Disorder in the cloudy/snowy/gray northeastern part of the Northeast US, my wife and I are desperate to find a cure short of moving to a sunnier climate.

Recent research has shown morning exposure to blue light to be especially effective in helping many with our problem. Philips is producing a highly rated LED device that seems to provide relief to may. 

http://www.amazon.com/Philips-goLIT...dp_top_cm_cr_acr_txt?ie=UTF8&showViewpoints=1

The unit looks great but for us as a retired couple on a limited budget the sticking point is the current price @ ~ $150.00.

I have to think that one could put together a very effective blue SAD light using just a few high power blue LEDs along with the appropriate dimmable driver, and optics for well under. The form factor of the Philips device is unimportant. A simple light bar should work as effectively.

I'm looking for specific suggestions of blue LEDs (~468nm wave length), dimable drivers, optics and any other necessary bits. Ideally these would all be purchased from one source to economize on shipping. 

High quality soldering is within my skill set but I lack experience building LED devices.

Thanks for any informed replies!!!

Hugh


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## Gunner12 (Dec 29, 2009)

LEDs, drivers, heatsinks, that's not hard to find. I just don't recall where I saw a dim-able driver. I'll post back when I find one.

How quickly would you like the parts shipped?

Anyone know if having a potentiometer as the sensor resistor(correct term?) will damage the driver if the resistance is changed during operation?


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## SciGuy (Dec 29, 2009)

Gunner12 said:


> LEDs, drivers, heatsinks, that's not hard to find. I just don't recall where I saw a dim-able driver. I'll post back when I find one.
> 
> How quickly would you like the parts shipped?
> 
> Anyone know if having a potentiometer as the sensor resistor(correct term?) will damage the driver if the resistance is changed during operation?


 
Gunner,

Thanks so much for the quick reply. I would love to build something within the next couple of weeks or so. While we have now passed the minimum duration of insolation portion of the winter, there are still several very dark months to make it through before things really brighten up.

Best Regards,

Hugh


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## was.lost.but.now.found (Dec 29, 2009)

Just my opinion, but $150 doesn't sound too high for a necessary medical device (if it works that is). That's only 5 months of $30 prescription copays.


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## waddup (Dec 29, 2009)

hey sciguy,

i just bought a light on a whim that might be just the ticket for you?

its the right wavelength i think to help with lack of sunlight

http://www.google.com/search?client=safari&rls=en&q=470nm&ie=UTF-8&oe=UTF-8

with a charger and 3 good quality rechargeable C size cells i think it could be run 12 hours a day or more easily

it emits a lot of light.

i paid $20 shipped, i really dont need it, i just liked the idea of blue light from a flashlight

if you want to try it you can have it for $20 same as i paid?

Our Blue LED Arrays use 470nm high-output LEDs.

Research indicates that blue light controls bacteria that cause acne and periodontal gum disease, and improves rosacea and *Seasonal Affect Disorder*. New research finds effectiveness against MERSA.

http://www.elixa.com/light/blue.htm

https://www.candlepowerforums.com/threads/255062


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## blasterman (Dec 29, 2009)

> I'm looking for specific suggestions of blue LEDs (~468nm wave length),


 
Standard blue Crees fit this criteria, and they are easy to find. Your real problem will be the dimmable driver because this feature tends to significantly increase the cost / complexity of the driver. It would be simple enough to just run 6 or 12 blue Crees in series with a non-dimming 350mA or 700mA driver.

Another issue is diffusion. Wide angle acrylic optics will take some of the 'bite' out of uber intense blue LEDs like Cree, but an even better idea would be to put them behind some diffusion material like Acrylic panels used for fluorescent lights.

Good luck with this. I live in Michigan so I know about the winter blues, but I'm just skeptical on the science.


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## SciGuy (Dec 29, 2009)

was.lost.but.now.found said:


> Just my opinion, but $150 doesn't sound too high for a necessary medical device (if it works that is). That's only 5 months of $30 prescription copays.


 
WLBNF, You're certainly correct about $150.00 not being outlandish for something that is needed. Its just that if I can build an even more useful device for a fraction of the cost it just makes sense to my Scottish ancestory

Most recent research shows that mounting the light source above the eyes is most effective probably since our blue sky is above.

Hugh


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## SciGuy (Dec 29, 2009)

waddup said:


> hey sciguy,
> 
> i just bought a light on a whim that might be just the ticket for you?


 
waddup,

Thanks so much for the kind offer! Mounting the unit an appropriate distance from ones face might be a challenge. I'm really hoping to build something with a fairly intense light field ~ 1ft square.

Best Regards,

Hugh


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## SciGuy (Dec 29, 2009)

blasterman said:


> Standard blue Crees fit this criteria, and they are easy to find. Your real problem will be the dimmable driver because this feature tends to significantly increase the cost / complexity of the driver. It would be simple enough to just run 6 or 12 blue Crees in series with a non-dimming 350mA or 700mA driver.
> 
> Another issue is diffusion. Wide angle acrylic optics will take some of the 'bite' out of uber intense blue LEDs like Cree, but an even better idea would be to put them behind some diffusion material like Acrylic panels used for fluorescent lights.
> 
> Good luck with this. I live in Michigan so I know about the winter blues, but I'm just skeptical on the science.


 
Blasterman,

Are you still a fan of the high power ProLight LEDs from Besthongkong? I thought that perhaps their LEDs, optics and drivers might produce a reasonable system.

In regards to the science, they have done very extensive studies that absolutely prove melatonin levels are knocked way down by exposure to intense white or particularly blue light. When this occurs during the early morning hours people feel peppier the rest of the day, have reduced cravings for carbohydrates and are more likely to fall asleep at a resonable hour the next evening. 

If I get even 15 minutes of bright sun in the morning I'm happy and whistling the rest of the day. While on the other hand two or three really dark days in a row create an incedible blue funk.

I'd love to see a picture of the light bars you created with the ProLight LEDS. It seems as if they went missing.

Best Regards,

Hugh


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## Gunner12 (Dec 29, 2009)

Maybe you can wire up each LED to it's own driver, and have a switch for each. That will make something like a stepped dimming, but it would also make for a lot of soldering and a lot of parts.

Having the LEDs behind a frosted panel could spread out the light.


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## was.lost.but.now.found (Dec 29, 2009)

SciGuy said:


> Its just that if I can build an even more useful device for a fraction of the cost it just makes sense to my Scottish ancestory


 
Absolutely - best of luck in your quest!!


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## blasterman (Dec 29, 2009)

> Are you still a fan of the high power ProLight LEDs from Besthongkong?


 
Yep. I'm moving everything from my prior web-host to Flickr, and must have missed that light bar pic. I'm upgrading the bar this week to get it up before the New Years Crowd, so I'll have to upgrade the pics. Adding some R2's and doubling the number of emitters. :devil: 

I really like the Best Hong Kong red and blue LEDs, and their optics work nice.

There's a difference between Best Hong Kong blues and Cree blues. The Crees are brighter, but their blue response is higher and a tad cyan. Best Hong Kong blues tend to be deeper in color and closer to Cree Royals. Visually the Best Hong Kong emitters look nicer because of their deeper color. But, Cree blues are brighter and technically fit in your wavelength requirement. Personally I'd mix a couple neutral whites in the mix just to make it look nicer.


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## SciGuy (Dec 29, 2009)

blasterman said:


> There's a difference between Best Hong Kong blues and Cree blues. The Crees are brighter, but their blue response is higher and a tad cyan. QUOTE]
> 
> Blasterman,
> 
> ...


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## blasterman (Dec 29, 2009)

Should be fine.

Some discussion on if it's an XRE or not, but that just means you should stay at 350mA.


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## SciGuy (Dec 29, 2009)

How about this as a dimmer/driver????

http://www.besthongkong.com/product...d=863&osCsid=b00a05b17f0ea73fd1ba8255b432fce0


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## Gunner12 (Dec 29, 2009)

The LEDs should work, but DX has really slow shipping though, be prepared to wait a few weeks.

The driver might work, but I'm not sure how well, as I've not seen it in use.


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## qwertyydude (Dec 29, 2009)

Perhaps instead of just focusing on a small treatment module, all the therapies are bright light oriented not specifically of any particular color or wavelength, you could just light your rooms with the most powerful daylight cfl's available AND always keep them on during daytime hours. Sounds counterintuitive that bright lights help relieve stress but they do help keep you up and awake which is an important part of treating part of the problem which is a broken circadian rythym. Bright lights help to set your circadian rythym, also when sleeping make sure it is pitch black and also as quiet as possible and don't take naps during the daytime when you're supposed to be awake. This helped reset my circadian rythym the quickest when it went haywire every two weeks due to messed up shift schedules in the navy. You'd be surprised just how much a good circadian rythym affects your day to day mood. And a lot of the whole SAD thing is in my opinion just people's natural sleep rythym not setting. Cause the symptoms everyone displays when their shift schedule was constantly changed mimiced on the dot SAD.


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## SciGuy (Dec 30, 2009)

qwertyydude said:


> Perhaps instead of just focusing on a small treatment module, all the therapies are bright light oriented not specifically of any particular color or wavelength, you could just light your rooms with the most powerful daylight cfl's available AND always keep them on during daytime hours. Sounds counterintuitive that bright lights help relieve stress but they do help keep you up and awake which is an important part of treating part of the problem which is a broken circadian rythym. Bright lights help to set your circadian rythym, also when sleeping make sure it is pitch black and also as quiet as possible and don't take naps during the daytime when you're supposed to be awake. This helped reset my circadian rythym the quickest when it went haywire every two weeks due to messed up shift schedules in the navy. You'd be surprised just how much a good circadian rythym affects your day to day mood. And a lot of the whole SAD thing is in my opinion just people's natural sleep rythym not setting. Cause the symptoms everyone displays when their shift schedule was constantly changed mimiced on the dot SAD.


 
qwertyydude, 

You bring up many good points. 

"you could just light your rooms with the most powerful daylight cfl's available AND always keep them on during daytime hours. "

The problem with lighting every room brightly and having them on all day long is at least two fold. First, it would be a much more expensive to retrofit many of our rooms to extreme brightness and power them with our very expensive NY electricity rates. Secondly, the light levels one can attain indoors are still vastly less than outdoor levels on a sunny day.

"when sleeping make sure it is pitch black and also as quiet as possible"

I absolutely agree that keeping your sleeping area pitch black is very helpful for the sleep end of the equation. I've either turned off or covered up all of the wonderful LED indicator lights that have fouled our sleep for years. The green "charge completed" light on my cell phone has ruined more than one nights sleep.

Thanks for the well thoughout reply. I stilll wish to build a dedicated blue source to get a concentrated early morning dose of happiness.

Hugh


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## blasterman (Dec 30, 2009)

Several years ago I saw a documentary on SAD, which as I recall was on PBS or something.

The conclusion by several researchers was that blue/intense light during winter months was beneficial, but that exposure had to be on various parts of the body that tend to get sun during the warmers months and also have thinner epidermis; back of legs legs, lower torso, etc. The conclusion was that SAD seems to concentrate in Northern Climates with adequate summers where people go from lots of exposure/activity outdoors to the winter dolldrums. It's this disruption that causes the various levels of depression, and people in more extreme northern climates or southern climates don't tend to get the disorder. Using a tanning bed in the morning for example significantly improved the attitude of their test group, so maybe they were on to something. It was also their conclusion that the process of naturally producing vitamin D is directly related to SAD, but not the blood levels of Vita D.

I have a couple relatives who are avid gardners during the summer months, and need to be kept away from razor blades and sleeping pills during the winter because their moods shift that badly.


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## Rexlion (Dec 30, 2009)

waddup said:


> ...Our Blue LED Arrays use 470nm high-output LEDs.
> 
> Research indicates that blue light controls bacteria that cause acne and periodontal gum disease, and improves rosacea and *Seasonal Affect Disorder*. New research finds effectiveness against MERSA.
> 
> ...


 Oh, does that mean I can fight gum disease by shining a Quark RGB on blue mode into my mouth? :laughing: I'll try anything once or twice...

But seriously, I have a couple of full spectrum fluorescents in the house and I think they have helped with wintertime blahs. Way less than $150.


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## Ekke (Dec 30, 2009)

qwertyydude said:


> *snip* Bright lights help to set your circadian rythym... *snap*



Actually.. It might be that it's really blue that is needed.. Just bright might not be enough.

http://www.medicalnewstoday.com/articles/110372.php
http://www.edn.com/blog/1470000147/post/580046458.html

Google for more.. I saw a document a few days ago about sleep, and there was a mention about Harvard university, melatonin & blue leds. Didn't found the original study, but I'm now interested about this subject too - well, it's 3:29AM at the moment.  

I think I will use Cree XP-E Royal Blue, because cone cells are more sensitive to its wavelength than "normal" blue, peak is 420–440 nm:




Royal Blue is 450-465nm, normal XP blue is 465-485nm and there isn't so big difference in the price.


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## fyrstormer (Dec 31, 2009)

Have you tried just using a really high-wattage halogen lamp? Halogens run hot enough to produce a full perceivable spectrum (not just visible) all the way from far-infrared to near-ultraviolet. It's basically sunlight in a quartz tube; even LEDs can't beat that. I keep a halogen lamp on my desk at work (with the UV shield removed) for exactly that reason. (my desk plant appreciates it too, which is a good sign.)

However, the trick is the light has to strike your face directly, not reflected off a wall or the ceiling.


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## SciGuy (Dec 31, 2009)

Ekke said:


> Actually.. It might be that it's really blue that is needed.. Just bright might not be enough.
> 
> 
> I think I will use Cree XP-E Royal Blue, because cone cells are more sensitive to its wavelength than "normal" blue, peak is 420–440 nm:
> ...



Ekke,

Good links on the topic. I've previously read several pieces on Dr. Figueiro but not the ones you posted.

My reading has led me to worry about overdoing the near UV end of the blue portion of the spectrum. There seems to be some potential for eye damage. In regards to the cones sensitivity to different colors, my understanding is that the melatonin photo receptors involved in melatonin suppression are not cones or rods but a third very recently discovered type. I would lean toward XP blue and not worry about cooking my retinas

Now lets get some more specific component ideas going for a LED newbie.

Hugh

Hugh


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## Dave_H (Dec 31, 2009)

I'm not sure if this is the answer but will toss it out (and I have
a second one).

For a few years I've been using low-cost camping lanterns which
use 12 white LEDs. Brands (in Canada) are Innovage and Journey's
Edge. They are cheap at $10-15, run on 4 D cells and have a 6v
adapter socket, and have a built-in PWM dimmer. The dimmer is
very efficient unlike constant-current linear drivers which act as big
resistors. For example, go to factorydirect.ca and search product
LA0012. I have seen them in two other local retail stores in Ottawa.
Total current is around 330mA so each LED is driven up to 30mA.

LEDs are mounted on a vertical PCB arrangement which points
three LEDs in four directions, but looks difficult to rework for blue
LEDs. However, removing this and replacing with a board with
LEDs mounted facing one direction may work; even a perf-board
arrangement.

A limitation of this approach is its utilization of low-power 5mm
LEDs, but the circuit might be able to drive two higher-power blue
LEDs.

One caveat, I found under continuous use, a few of the LEDs
have gone. I chalk this up partly to cheap LEDs, also poor thermal
management even at this power level. This could be improved.

Dave


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## Dave_H (Dec 31, 2009)

My second idea is to mod a LED worklight. These have typically
rectangular arrays ranging from two dozen to 60-70 or even 100
white LEDs. They usually have 3-cell internal batteries which are
charged from a wall-plug adaptor, some from 12v. None I've seen
are inherently dimmable though.

I have a few, never payed more than $20 each, even at full price
could easily come in under $50, not including new LEDs.

Dave


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## rikkitikki (Nov 20, 2012)

Dear moderator,
I know this is a really old thread but here goes anyway as I feel the information is new,up-to-date, helpful and relevant.


SAD is a nasty , subtle , oppressive disorder and I believe I found a low-cost way to deal with it.
All the parts you need are available on ebay !


1. 12 volt 30cm Blue Led strips for automobiles are available from Hong-Kong for a few dollars. These emit an intense blue light. The blue light spectrum is fairly narrow. In the depths of winter we don't get much blue light so in my opinion any blue wavelength is good. Yes there are some valid theories from the medical community on eye damage caused by blue light. What do you value most, your mental health or some extreme animal models demonstrating eye damage from blue light? 

2. 12 volt 30cm Green light strips. Also available on ebay. Please see this link that shows the relevance of green light in natural daylight.
http://en.wikipedia.org/wiki/File:Rayleigh_sunlight_scattering.png

3. A 1 amp 3v-12v power adapter will provide dimming. Simply change the voltage setting to select light level. Suggest hooking up 3 strips of each colour. Current draw will be between 0.6 and 0.8 amps. This equates to about 7-10 watts.


4. The LED strips have adhesive backing so can be stuck on a board and optionally covered with frosted plastic cover. Your local home supply store will likely have something that looks good and can be adapted.

5. Several sources suggest that the lights should be mounted above head level and aimed to shine down into the eyes. The light does not need to shine straight into the eye in a blinding manner, it only needs to shine in-directly from the side.


All the best !


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## Sub_Umbra (Nov 20, 2012)

I'd have to advise caution with blue. Even Royal Blue (RB) at ~465 nm puts out enough invisible UV energy to make clothes washed in modern detergents _fluoresce in the dark_ (thanks again Icebreak). I doubt if that's something one would want to spend lots of time gazing into. 

There's quite a bit out there on the Interwebs about combating SADS with light therapy.


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## uk_caver (Nov 21, 2012)

rikkitikki said:


> 1. 12 volt 30cm Blue Led strips for automobiles are available from Hong-Kong for a few dollars. These emit an intense blue light. The blue light spectrum is fairly narrow. In the depths of winter we don't get much blue light so in my opinion any blue wavelength is good. Yes there are some valid theories from the medical community on eye damage caused by blue light. What do you value most, your mental health or some extreme animal models demonstrating eye damage from blue light?


Since white LED light has a lot of blue in it, I'm not sure what the point of having specific b lue light is - seems a waste of LEDs when white LEDs are also good for general lighting.



rikkitikki said:


> 2. 12 volt 30cm Green light strips. Also available on ebay. Please see this link that shows the relevance of green light in natural daylight.


The link shows the presence of green in natural daylight, but not its relevance.
There is UVA and UVB and lots of IR in natural daylight, but that _in itself _wouldn't suggest a need to recreate them indoors.



rikkitikki said:


> 5. Several sources suggest that the lights should be mounted above head level and aimed to shine down into the eyes. The light does not need to shine straight into the eye in a blinding manner, it only needs to shine in-directly from the side.


That would seem to suggest that directional overhead white LED lighting could be sufficient, as well as being useful for other things.


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## AnAppleSnail (Nov 21, 2012)

I experienced a HUGE change from ceiling-bounced neutral-white LED strips. I think that in winter I like the higher CCTs since I do not see very much sunlight. The CCTs that make me feel warm and fuzzy are 4500-6000K white. Replace your home lighting with these (And trash the 2300CCT CFLs) and you should be well on your way.


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## fnj (Dec 6, 2012)

As noted here and elsewhere, bright blue LEDs could be very injurious to the eyes. Anyway, blue is not what you need to combat SADS. You want intensity over a full spectrum with a high CCT. They are readily available; just not in LED form for technical reasons. I don't know if posting the link is kopacetic, but just google "blues buster light bulb" and you will find them on the first line of the search results. These guys now make full spectrum daylight CFLs too. You can also google for "full spectrum solutions" - they make full spectrum fluourescents.

The holy grail for SADS sufferers is very intense glorious noontime sun and these bulbs give you that.


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## SemiMan (Dec 6, 2012)

fnj said:


> As noted here and elsewhere, bright blue LEDs could be very injurious to the eyes. Anyway, blue is not what you need to combat SADS. You want intensity over a full spectrum with a high CCT. They are readily available; just not in LED form for technical reasons. I don't know if posting the link is kopacetic, but just google "blues buster light bulb" and you will find them on the first line of the search results. These guys now make full spectrum daylight CFLs too. You can also google for "full spectrum solutions" - they make full spectrum fluourescents.
> 
> The holy grail for SADS sufferers is very intense glorious noontime sun and these bulbs give you that.



Bare blue LEDs can be dangerous, but diffuse blue LED light would still be far lower in UV and even blue content in a typical installation that sunlight, even under somewhat cloudy skies. Keep in mind as well you need blue/UV to synthesize natural vitamin-D, which has powerful anti-cancer properties which is not really replicated in digested vitamin-D from studies I have read.

FNJ, I don't believe that current medical research agrees with your statement w.r.t. full spectrum versus blue-leds.

Some recent research has shown a high correlation between full blown SAD and a melanopsin gene mutation, summary here: http://www.ncbi.nlm.nih.gov/pubmed/18804284

That would imply to me that treatment for SAD related disorders may be best treated with light sources that simulate melanopsin and suppress melatonin and drive circadian cycles. Depending on the article you read, that peaks about 450-480nm and is <10% by 520nm.

If that is true, then broad spectrum lights and/or green will have little value in the treatment of SAD. You need blue, but you don't need really short wavelengths, you can stick to the longer wavelengths.

Semiman


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## jtr1962 (Dec 7, 2012)

SemiMan said:


> Keep in mind as well you need blue/UV to synthesize natural vitamin-D, which has powerful anti-cancer properties which is not really replicated in digested vitamin-D from studies I have read.


Are you saying that sitting under blue LEDs should be as good as sunlight for synthesizing natural vitamin-D? And if so, would a few royal blue XT-Es running at maybe 1 amp be enough? I'm asking because although I don't seem to suffer from SAD, I get almost no sunlight. I tend to be a late riser, which means in winter months I might be up only a few hours before sunset, and typically don't venture out until after dark. In summer I have to stay in until after dark most days on account of the heat (I just can't tolerate temps much over about 75°F, less if I do any physical activity) and also the poor air quality. What sunlight I do get is whatever filters into my bedroom window but I suspect the glass filters out most of the UV, and perhaps a good portion of the blue.


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## Anders Hoveland (Dec 7, 2012)

You want natural full spectrum light? My suggestion would be to place one of those energy saver halogen bulbs and a cool white LED replacement bulb together behind a light diffusor to combine the two spectrums together. 

https://www.solux.net/cgi-bin/tlistore/infopages/index.html


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## SemiMan (Dec 7, 2012)

jtr1962 said:


> Are you saying that sitting under blue LEDs should be as good as sunlight for synthesizing natural vitamin-D? And if so, would a few royal blue XT-Es running at maybe 1 amp be enough? I'm asking because although I don't seem to suffer from SAD, I get almost no sunlight. I tend to be a late riser, which means in winter months I might be up only a few hours before sunset, and typically don't venture out until after dark. In summer I have to stay in until after dark most days on account of the heat (I just can't tolerate temps much over about 75°F, less if I do any physical activity) and also the poor air quality. What sunlight I do get is whatever filters into my bedroom window but I suspect the glass filters out most of the UV, and perhaps a good portion of the blue.




Not sure about the Vitamin-D production. I have not looked at the action spectrum for that in some time so not sure if <400nm UV is essential or if you can get away with deep blue.

My comments were directed at SAD which latest research has shown full blown SAD to have a correlation with a mutated melanopsin gene. The spectrum I was referring to was for melanopsin stimulation / melatonin suppression. 

Would be good to research the Vitamin-D action spectrum ..... and there was my distraction for the morning. Seems you need <310nm! Not much benefit from blue LEDS there: 

http://www.niwa.co.nz/sites/default/files/action_spectrum_for_vit_d_synthesis.pdf

Semiman


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## jtr1962 (Dec 7, 2012)

Thanks for the link. Very interesting-300 nm is optimal for vitamin D synthesis. Looks like I might as well just try to get a bit more sunlight outside then (my window glass probably filters everything under 310 nm). Even if 300 nm LEDs were readily available and inexpensive, making an array could cause more problems than it solves.


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