Vitamin D from the greenhouse: What type of glazing will allow UVB through?

Hello everyone,

As I am researching the various components and uses of my planned passive solar greenhouse, I am arriving at the question of how best to maximize potential human Vitamin D production by allowing transmissibility of UVB which allows our bodies to create what we need.  I have read that most glass allows UVA but stops UVB.  And polycarbonate, too.  I will likely use some sort of greenhouse poly  (maybe 10 mil), but have not seen much info on how to let in UVB overall.  It seems to be all about blocking UV rays.  Any thoughts and/or expertise?  

Thanks in advance!

Hi Tracy,
Welcome to Permies.com

I don't know of any coverings that do not block it, other than clear glass... which makes beautiful greenhouses but is way more expensive than plastic usually. Maybe you could do one end in glass to sunbathe in, and the rest in something cheaper?

I did find a paper a university put out on UVB transmission. https://www.bu.edu/summer/files/2019/11/McFadden-Maeve-POSTER.pdf

What is your climate? And how much time do you plan to spend in the "barbecue zone?" My hazy understanding is that it doesn't take a lot of time in direct sun for skin to generate adequate D. I may be mistaken, but I don't know that I would design my greenhouse around it.