T Nation

calcium v. magnesium

ok, so supplementing calcium and magnesium (among other minerals) is important, but i’ve read here in t-mag before that cal. and mg. compete for receptors. if that’s the case, why do vitamin makers insist on pairing them?! my multivit pairs 'em, and i’m at a loss as to which i should supplement separately. at the moment i take a chelated mg. separate, but i forget to do that when i’ve just had a meal that has significant calcium in it (i.e., cottage cheese).
what’s the dealy-o on this?

Life on Earth has existed for billions
of years taking in calcium and magnesium
at the same time. I would not give it
the slightest trace of concern.

If you want the absolute best absorption of magnesium and calcium you should take them separately. They are both divalent cations and they compete for absorption. I did my undergraduate research on how phosphorus, calcium, and magnesium interact with each other in the small intestine and the absorption of one can effect another. If you were taking ZMA at night I would avoid calcium, otherwise I wouldn’t worry about it too much like Bill says.

bill:LOL! thanks to you both