Hi - I am in Niagara and seeing a rheumatologist in Hamilton for osteoporosis. My GP has ordered most of my blood work including the vitamin D. Most issues I deal with my GP and if they have any questions they contact the rheumatologist for direction and advise. If you are wanting to see someone other than your GP just make sure you are referred to someone who specializes in osteoporosis. I have found that not all endocrinologists and rheumatologists do. I have only been dealing with this diagnosis less than a year now and it has sent me down the rabbit hole of misinformation and fear. I hope you can find someone you feel confident with to guide you through this journey.