I brought this up earlier.
I started taking Vitamin C.
I got up to 10 pills @ 1000mg a day.
You stop once you have "consistent" runny bowels. (Hello ladies!!!!) At first you would have them each time you increase the amount.
My skin cleared up. It did more for me than anything.
Then I got cocky... (can I say that?) stopped taking them and had fish in chips twice and a peters burger.... Oops. (I'm intolerant to wheat) and my skin broke out again. Not as bad though.
http://www.doctoryourself.com/psoriasis.html