LONGECITY

Title.

I have only found bulbs. The vitamin-D bulbs can be found and purchased at a pet-supply store; they are mainly used for reptiles.

Why would you ever want this? UV-B ages your skin rapidly, it's the range of light responsible for quickly aging skin.

Why would you ever want this? UV-B ages your skin rapidly, it's the range of light responsible for quickly aging skin.

UV-B is needed for vitamin-D synthesis and vitamin-D is a vastly important anti-aging "hormone" ... it is the UV-A which causes the "tanning" effect and is known to damage the skin much more so than UV-B.

No, UVB damages and ages skin as much if not more so than UVA, that's why it's so important to get sunscreen that blocks both. If you need more vitamin D then get a little sunlight or just take supps or eat wild salmon. It's not worth the risk of sitting in UVB light. D3 is super cheap and probably the cheapest supplement of all. Just take 4000 IU with fatty foods and you're set.

I mean, it's right in the wiki, with citations: https://en.wikipedia...wiki/Photoaging

Depending on your latitude, you get no Vitamin-D from sunlight at all for around half the year. 

In San Diego, the Spring & Fall Equinox marks the beginning and end of Vitamin-D season.

Timing is also important, with little UVB exposure outside a few hours surrounding solar noon (11 AM - 2 PM daylight saving time).  This window is a bit larger in June & July.  

In Northern latitudes (with a much shorter Vitamin-D season), some have observed a deficiency related "disease belt" (specific diseases more common in Northern Latitudes), possibly due to chronic D deficiency.  

https://www.ncbi.nlm...pubmed/18767337

I've been experimenting with supplements & blood levels and it takes around 5000IU/day to keep my D levels up during the Winter.  

There is a school of thought that Vitamin-D from sunlight (UVB) is more active (sulfated form) than Vitamin-D from supplements.  

https://www.selfhack...ing-winter-nyc/

I'm a bit of a sun worshiper, & at 61 have incurred little damage from this over the years.  The trick is to avoid getting badly burned.  

I looked into UVB sunlamps a couple year ago and was disappointed in what I found.  Very expensive, and a bit tricky to use.  Lamps must be placed fairly close to skin, & timed accurately. The lamps are also small, & would only cover part of the body (stomach or back).   

Since the body can store some Vitamin-D for a time, I try to load up from mid-day sun exposure in August and early September; & supplement 5K of D-3/day October through April.  

SPERTI makes the best lamps I found.  "Only FDA Recognized Vitamin-D Light Box" Didn't have time to look this up before.

https://www.sperti.c...min-d-light-box

http://www.alaskanor...ASABEgLaXPD_BwE

Note the small size, and how close the lamps are to the people.