Dr. Wang: As we all know vitamine D is very important to our bone health. Sitting in glass room will not have your skin to produce vitamine D for you.  Glass blocks UVB of Sunlight. It is UVB to induce vitamine D in skin (More on NY Times).  中国60岁以上， 男23%， 女49%有骨质疏松。骨折（骨盆， 脊柱，等）是个大问题 （More on 百度）。