Psoriasis and Anemia?

I was recently diagnosed as anemic by my GP. He put me on a course of iron tablets 3 times a day and I have followed the instructions rigidly (swallow at least an hour before food, no caffeine, milk etc). I finished the tablets last week. I wasn't aware of any symptoms when I started the tablets (it was picked up during a blood test when I went to see him about joint pain) but I now have all the classic anemia symptoms. All the tablets seemed to do was to make my psoriasis and joint pain worse - I was scratching myself red raw while I was on them, but within 48 hours of finishing the course, things calmed down again. I'm a bit worried because obviously the iron tablets aren't working, and I don't know why. I've booked myself back in for another GP visit, but the earliest appointment is a month away. Someone told me this week that psoriasis can cause anemia by preventing your body absorbing iron. Does anyone have any experience of this or know if it is true?