Posted by Larry Hoover on April 4, 2003, at 9:43:09
In reply to Larry, Re: Magnesium Hydroxide, posted by Caleb462 on April 3, 2003, at 22:28:58
> You said magnesium hydroxide works too, yet on that guy's site (can't remember his name), he says magnesium hydroxide has poor bioavailability and has no known use other than as a laxative. So what's up?
I'm thinking purely as a chemist when I say that; it has lower bioavailabity than other salts, but it's got to be better than magnesium oxide.
Mag hydroxide is marketed as an antacid. For that to work, the hydroxide has to be labile (easily moved). The reaction is:
2HCl + Mg(OH)2 --> 2H2O + Mg(Cl)2
The laxative part is due to the fact that both Mg(OH)2 and Mg++ ions are hygroscopic; they draw water to themselves. Now Mg(OH)2 does that very poorly, relative to Mg++ (Mag hydroxide is milk of magnesia, which is milky because it's not a solution. It's a suspension.), making me think that the laxative effect is due to Mg++, which is bioavailable. A lot of people already have milk of magnesia in the house. I suggested it so people don't run around buying expensive supplements if they've got another option available to them.
That's my rationale. I can't find anything in the literature that either supports or refutes my logic.Lar
poster:Larry Hoover
thread:214008
URL: http://www.dr-bob.org/babble/20030402/msgs/216148.html