Many drugs deplete nutrients. Prednisone is one of the worst in this regard:

Here is a list of what to watch out for:
http://www.chiro.org/nutrition/ABSTR...steroids.shtml

IMO the potassium and magnesium depletions are signficant and serious.
There are foods high in potassium, like V8 juice and cantaloupe.
Magnesium is in almonds --270mg/3 ounces. --I'd use unsalted.

I'd get the B12 and Vit D tested for. Your blood test should show 400 or above. (some doctors call 250 normal and that is antiquated information). I have a B12 thread here:

http://neurotalk.psychcentral.com/thread85103.html

Estimates are that about 1/2 of people in US are low in D.
Here are two medical videos on D3 and how important it is:
http://neurotalk.psychcentral.com/thread92116.html
More information at grassrootshealth.net

If gluten intolerance is the reason for your autoimmune issues, continuing to eat gluten will make you worse and worse. People with autoimmune disease should be tested for gluten issues:
http://neurotalk.psychcentral.com/forum13.html
I am always concerned when I see young males with this problem, as they are not in the common stats for onset which is 50 and over for males.