I think if you're ever going to supplement anything then Vitamin D is very safe and you should honestly do it if you're mostly indoors. 2K IU a day is gonna be enough most likely. Could also explain why your dental health has suffered despite getting ample amount of calcium. I personally recommend Thorne D3/K2 4-5 drops daily with a fatty meal. This is the only supplement I use and I think it's of high quality, but a bit pricey. It lasts for a long time though.