love magnesium. Big fan. With such a calcium push in the USA,
  and not eating as much salad as I want. [I like salad], I take
  magnesium a few times a week just to keep in balance.

  I don't worry about potassium so much as that shows up in foods
  that try to lower sodium content a lot. But magnesium
  deficiency, I believe, is a strong source of sudden death by
  heart attack along with an excess of calcium.

  [I treat them as opposites, as calcium tends to constrict or
  tighten and magnesium tends to relax, even though they're not
  strictly opposites in every way]   I do the same with
  zinc/copper. Zinc=male, copper=female. (zinc leads to
  testosterone, copper leads to estrogen). As I drink a lot of
  coffee (source of copper), I balance it out with zinc a few
  times a week. I don't know a lot of strong sources of zinc
  outside of pumpkin seeds, but thankfully zinc tablets are really
  cheap smile emoticon .