Google Scholar (https://scholar.google.com/) is a great place to search for answers like your question. I just did a search for "prednisone cause bone loss" and the first link it found was:

Low-dose prednisone induces rapid reversible axial bone loss in patients with rheumatoid arthritis: a randomized, controlled study
-- http://annals.org/aim/article-abstract/706870/low-dose-prednisone-induces-rapid-reversible-axial-bone-loss-patients

Here's the search results link:
-- https://scholar.google.com/scholar?hl=en&as_sdt=0%2C24&q=prednison+cause+bone+loss&btnG=

John

Prenisone...is this a steroid? I wish my doctor would prescribe that to me. Instead I am on Methotrexate once a week. I suffer in pain and difficulty in walking and no pain pills

Yes, prednisone is a steroid. I’m not a doctor and have no training but from what I understand prednisone is the drug normally prescribed for PMR. It would be a good question for your rheumatologist or doctor.

@Dear oragongirl, I used mrthotrexate weekly injections for over seven years Under care of a rheumatologist) but now my anemia has become serious. So i had to go off methatrexate because it is not good to use with an anemia disease. It did help me. (Just a little information .