Re the iron deficiency, magnesium is involved in over 300 biochemical reactions in the body. Is it possible it may be related to iron? I don't know, but I do know that magnesium supplementation was not only the best antidepressant I ever took (and I tried numerous Big Pharma varieties) but it also cleared up my dry skin!

Here is a good primer on magnesium: http://www.krispin.com/magnes.html