@Jean:

Since you like to "research" here is a web-based shorter
version of the reference I use by Ross Pelton RPh and James LaValle RPh: Drug Induced Nutrient Depletion Handbook:
2nd ed.

http://www.chiro.org/nutrition/ABSTR...orticosteroids

The information ultimately derives from PubMed/Medline published studies.

There is another a bit newer, but similar and less technical:
The Side Effects Bible. By Dr. Vagnini MD
http://books.google.com/books/about/...d=GwGKoTxXbQQC