B12 and R-Protein (Haptocorrin also known as transcobalamin-1) question

[armyswat]

I know B12 to be absorbed.. it must to be protected from the stomach acid (HCl), so it needs to be coated with the R-Protein or Haptocorrin which is excreted from the saliva glands.....

Everything is fine with sublingual, because it stimulates saliva and it can be coated..

But how does B12 is being protected with R-Protein if you swallow powder capsule or put some B12 powder inside a juice and drink it up?

Or B12 capsules.. they go straight into the stomach without stimulating the saliva glands, therefore they're not coated with R-Protein protection and they get destroyed??

From what I know also.. R-Protein is not being excreted from parietal cells. it doesn't say it in wikipedia or any other place.

 

[helen1]

The consensus seems to be that b12 needs to be taken sublingually, transdermally, or by injection. The oral route as you've shown is minimally absorbed.
@armyswat

 

[armyswat]

The consensus seems to be that b12 needs to be taken sublingually, transdermally, or by injection. The oral route as you've shown is minimally absorbed.
@armyswat

Not true, there was a study, the the oral route (not sublingual), is the same as an injection ( if that's true i can assume it's same as sublingual as well - I've also seen somewhere that sublingual is same as oral for B12 deficiencies) http://www.nature.com/ejcn/journal/v69/n1/full/ejcn2014165a.html

From this it means somehow we do get the oral B12 capsule powder.. but it doesn't make sense to me, since we need R-Protein to be stimulated in the salivary glands... by chewing or something.. and when we swallow capsule powders.. how does R-Protein gets binded to B12 to protect it from the stomach acid?

I'm asking here if R-Protein goes from the mouth down the stomach even without chewing stimulation..

From what I know.. no R-Protein.. means no B12 because without the R-Protein it will get destroyed by stomach acid.

 

[Sea]

I'm asking here if R-Protein goes from the mouth down the stomach even without chewing stimulation..

From what I know.. no R-Protein.. means no B12 because without the R-Protein it will get destroyed by stomach acid.

We are continually producing saliva and swallowing throughout the day. The R-protein does not bind with the B12 in the mouth but in the stomach. With dietary B12 the R-protein has to wait until the B12 has been separated by stomach acid from the protein it is bound in before it binds with B12. With supplemental B12 which is already free R-protein can bind immediately.

The general consensus is that sublingual B12 is not absorbed sublingually. It is swallowed over a longer period of time than a swallowed pill. The advantage is that because only a limited amount of B12 can be absorbed at one time a longer timeframe results in more absorption overall. The same outcome could be had with multiple smaller swallowed doses.

It also seems to be that in some people with limited R-protein or Intrinsic Factor large doses of oral B12 are enough to overcome the absorption problem as some B12 is absorbed directly and some escapes the degradation from the stomach acid. Others have to resort to injections or transdermal applications to get enough.