I sure didn't know that we need a bit of acid in order to make use of the magnesium in food. But we do.

Here's my list of foods containing magnesium:
http://www.health-boundaries-bite.co...Magnesium.html

I always take my magnesium supplement with either vitamin C, or hydrochloric acid.

Not everyone can take hydrochloric acid... but I read this really interesting thing about how a little of it can keep people from getting h.pylori...

h.pylori in the stomach lining can be a cause of low B12, and presumably low magnesium, also.