From: fitcat@optonline.net   
      
   On Monday, August 17, 2015 at 7:08:51 PM UTC-4, Peter Fairbrother wrote:   
   > On 17/08/15 12:43, Grokman Grokman wrote:   
   >    
   > > " nope. You can't use the reactive form in pills, it would hurt people."   
   > >   
   > > If you agree that the product of "reactive" MgO and HCl is MgCl2 and H2O,   
   what exactly is hurting people?   
   > >   
   >    
   > The unreacted MgO.   
   >    
   > Both before it gets to the stomach (throat, oesophagus), and then before    
   > it reacts with HCl in the stomach.   
   >    
   >    
   >    
   > Of course there probably won't be much unreacted "reactive" MgO left if    
   > the pill is left out - because "reactive" MgO is hygroscopic, absorbs    
   > moisture from the air, and turns into the hydroxide.   
   >    
   > No manufacturer is going to put "reactive" MgO in a pill for that reason    
   > alone, it would spoil the pill; and then there is the caustic effect,    
   > for which that goes doubly - reactive MgO is just not suitable for pills.   
   >    
   >    
   > You can put unreactive MgO into pills, it is safe and does not absorb    
   > moisture, but only a very small proportion of it will react and turn    
   > into MgCl2 under normal stomach conditions. The rest will just pass    
   > through the gut unchanged.   
   >    
   > If you have a suitable form of reactive MgO then you can add it to water    
   > to form a suspension of Mg(OH)2. They feed this to calves sometimes, so    
   > I guess at least a veterinary grade is available.   
   >    
   >    
   >    
   > But mostly people use magnesium hydroxide in pills, not magnesium oxide.   
      
      
   "But mostly people use magnesium hydroxide in pills, not magnesium oxide."   
      
   If you google   magnesium hydroxide for sale  you will find only 1 company   
   (initially) that sells Mg(OH)2, and this is in bulk. All the other listings   
   next to bulk Mg(OH)2 are in fact MgO, which is by far most common form of   
   supplemental Mg, and almost    
   exclusively found in multivitamins.    
   No online supplement provider (Swanson, PipingRock, PuritanPride, Vitacost,   
   etc) provides Mg(OH)2.   
      
   Next, your take on MgO doesn't have much leeway:    
     If MgO is reactive, it's harmful (caustic), and therefore not safe or usable.   
     If MgO does not become caustic/harmful, it's not reactive, and therefore   
   dietarily useless.   
      
   Yet, supplemental MgO is characterized as a poor Mg source, but not as a   
   useless source, something on the order of 30% efficiency, altho it is not at   
   all clear how they are measuring this.    
      
   I just chewed on an MgO tablet, and no caustic reaction, my gums/palate not   
   shredded. You will probably say that is bec it was unreactive MgO, and if so,   
   I've been snuckered for years, along with millions of other vite-heads.   
      
   So the next step, given my dearth of analytic facilities, is to drum up some   
   .1M HCl (from the wife's hospital, hopefully), and see if an MgO tablet   
   completely dissolves -- it seemed to dissolve pretty well in my mouth, but   
   ther was still some grit.   
   If that is the case, it should be safe to assume that the MgO is indeed   
   reactive, and if I can chew it for several minutes, then it is safe to say   
   it's not caustic.   
      
   It should then be safe to conclude that MgO in HCl results in MgCl2, to   
   completion.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)