low carb diet, possible magnesium deficiency??

I was just wondering about magnesium since Caz has mentioned having such great results with it.
Are you aware of any info/study, etc. that links low carb or a heavy meat diet to magnesium deficiency? I was wondering whether this could be the case as it competes for receptors with calcium and there is something about meat and creating extra calcium in the body? (I am not an expert but seem to remember reading this somewhere) Also, I am trying to make some conclusions from my own experience of when I was low carbing having a racing heart from which I have never quite fully recovered following a heavy meat WAPF diet. I am considering supplementation, but was curious to learn what others have to say. Thanks!