Results of clinical trial Jan 2012 showed that vitamin D and cofactors built bone at least as well as bisphosphonates or strontium ranelate.
The trial used: vitamin D(3), vitamin K(2), strontium, magnesium and docosahexaenoic acid (DHA)
This has been indicated many times before, but this is the first clinical trial that we are aware of that proves it.
Some of the links from the VitaminDWiki web page include: