@debbik I think there are only a modest number of reports of people building bone with nutrition alone. And I believe there are few or no studies showing that this can be done or reliably done for a significant percentage of people. Please note that some of those who have increased DXA scan measurements with "nutrition" are actually taking Strontium Citrate as a "supplement" and that is a whole other topic to wade thru. Whether or not this is a good approach is complicated but it is not using nutrition - it's using a trace mineral in huge amounts as a drug.
Most knowledgeable people seem to think nutrition in general and certainly calcium and vitamin D (and probably vitamin K2) are important but not sufficient to increase bone density. And there is, surprise surprise, disagreement about how to get these nutrients and how much of them to get.

Exercise in the form of heavy resistance training done correctly has been shown in several studies to build bone in the spine and improve some aspects of bone quality in the hips. See Belinda Beck and her LIFTMOR and related studies. Exercise, depending on your situation of course, can generally give more clear cut bone and health improvements than nutrition. That's my opinion but I don't know of any studies trying to investigate that.