CV and mad panic behaviour

[LP]

It's often propagated by the health industry that you need supplements, unless you have some medical condition that affects your production of vitamin-D you do not. Females are about 10x more likely than men to need supplements as they age due to biological concerns.

UV radiation is a continuous spectrum, that is divided in UVA, UVB and UVC to simplify discussions about it's effects on biology.

In reality all UV is attenuated by glass and other transparent surfaces, but it's not a cut-off filter effect. It is a curve like the graph below with UVB between 285 and 315nm, UVB is only a small percentage of solar UV radiation.

Note that graph is based on 10mm glass, most homes or buildings only have 3mm or 4mm glass!



Car windscreens and, greenhouse glass some of which contain reflective films can greatly alter the effect. But all it does is change how much time you need to spend in the sunlit window, being behind simple glass does not stop it the production of vitamin D it just slows the rate of production!

Plus, be careful reading websites, the data might be based on and targeted for people living in the Arctic circle, but then they are pale white in general for a reason, it is not an accident many are translucent blond!