Vitamin D, along with calcium, helps with the keeping our bones strong, however, when there is low amounts of Vitamin D it is associated with higher incidents of fractured bones not the bone pains that you have described. I suggest you ask the MD for tests to be done and find a diagnosis of your issues. If you are still concerned about Vitamin D, a multivitamin with Vitamin D 400 IU is sufficient. You should not go over that amount in supplementation. Vitamin D is available through our foods also. Fortified milk, breakfast cereals, egg yolks, fatty fish, fish oils, and the sun. Sit at a window with the sun shining in for about 1/2 hour (few times a week) and that will help you get enough Vitamin D.