Magnesium Deficiency in Celiacs

I was reading this month's Oprah -- yes, I'm a little embarrased to admit it, but I read it for the articles! ahem--and noticed a tiny little reference to the glutens.  In a question and answer article on medical issues, someone wrote asking about magnesium and copper deficiencies.  The author of the question had been told by a dietitian that he had a severe magnesium and copper deficiency.  The expert responding to the question was skeptical, stating that it is rare to see the symptoms of a severe deficiency in these minerals in anyone not suffering from "Chron's disease or a gluten sensitivity".  Interesting.  Magnesium deficiency can cause serious symptoms, like frequent migraines, personality changes, depression and exhaustion.  Worth checking into, for sure.