Think of it like this: Hot water is like a magnifying glass for the sun
Low vitamin D levels have been linked with problems such as bone loss and fractures, especially in higher risk groups
Oct 2001)
Now, I will say that the risks, at least theres a way to do this, where you can mitigate some of those risks, or evaluate for some of the main, I guess, problems that some detractors of using this have indicated, like, for example, I think you mentioned like a loss of muscle mass, right
The big deal with this is that with very few exceptions, nothing in the body can lengthen telomeres
H.BorowitzD.GelfondD.et al (2014)