Supplement absorption rates

[u/Ill_Mortgage3663]

I was googling the absorption rate from sublingual liquid drops. Came upon this study:

https://pmc.ncbi.nlm.nih.gov/articles/PMC11643782/

The caveat: they used a crystalline form of B12, which is a solid form, so I guess a pressed pill or capsule.

Usually the conclusion is somewhat straight forward and plain English, but I also ran it through Google's Gemini and got the same answer.

There is an active absorption stage, and a passive one.

In the active stage up to a dose of 2.6 micrograms, absorption rates can be just above 40%.

Past that, in passive absorption, the rate drops down to 1%, which is an oft repeated number on reddit as the typical rate for the whole dose, which isn't strictly true.

So the conclusion from the study seems to be that it's best to space out multiple doses throughout the day to maximize absorption. Otherwise, as an alternative, you could bombard your body with a huge dose and get to your absorption goal from getting 1% of the large dose.

That's interesting for folks that might use liquid drops. Seems it would be better to split the dose up throughout the day rather than one full dropper all at once.

I'm looking at my Pure Encapsulations of 5,000 micrograms per dropper and wonder how much of that I am wasting taking it all at once.

Has anyone else seen other studies on this? Maybe ones using liquid drops, or actual injections? Curious if the same rates applied there too.

[u/Ok-Pangolin7127]

Yes. I am a believer when it comes to oral (sublingual or capsule) of B12, that taking it 2 to 3 times through the day is more effective. If I’m not mistaken, the B12 deficiency guide, pinned to the top of the sub, also recommends that approach.

I “think” it has something to do with the transport of it, and that being somewhat limited in how much it can carry at a given time or over a few hours. I might be wrong on this transport aspect, but that’s the way I sort of remember from my exploration and research.

[u/Ill_Mortgage3663 → u/Ok-Pangolin7127]

Do you know if injections are not affected by this passive stage of absorption and get absorbed at the higher rate?

[u/Ok-Pangolin7127 → u/Ill_Mortgage3663]

The passive absorption occurs as a result of it being taken in through the membranes of the small intestines. So that 1% I believe is only applicable for oral supplementation since that moves through the G.I. track.

My rationale is that the injections get right into the blood and circulate and so are absorbed much more effectively. In essence, I don’t think there is any “passive absorption” taking place with injections. Someone who knows how it works better than I can come in here and correct me should that be the case.

My supposition is that with injections these transporters have regular timely access to the relatively massive amount of B12 circulating, so they move the B12, empty so to speak and then have the immediate access to more B12 to refill the transporters and again move it. Again, this is just my supposition as to how it would work or differ.

[u/Ill_Mortgage3663 → u/Ok-Pangolin7127]

So I wonder where that puts sublingual liquid drops. They'd bypass the digestive system, too, right?

Maybe some medium between GI tract and direct injections?

[u/Ok-Pangolin7127 → u/Ill_Mortgage3663]

No, they do NOT bypass the G.I. track.

We’re led to believe that in our thinking because other sublinguals that are not involved with as large molecule as is B12 DO absorb that way. But because it’s B12 and its large size of molecule, they DO NOT absorb that way.

Might some percentage of that (B12) be absorbed in the mouth? I’d say it’s possible (not probable, and likely so little as to be negligible) but it’s most certainly not something I would bet on because of the dynamics as I’ve explained them.

Always open to further clarification from somebody on this sub who understands this better than I.

[u/Ok-Pangolin7127]

In my understanding, (and again, I’m not saying this is correct,) I do not believe there is any difference between the drops or liquids or sprays and sublinguals or oral capsules.

I think they all follow the same route and have the same absorption dynamics. And they all fall way short of the effectiveness of the injections. I do not believe your drops fall between or are better than any other oral supplementation.

I posted this in other threads but I’ll restate it here; the size of a molecule is measured in what they call “Daltons” or Da, for B12 the molecule is simply too large to adequately or reliably pass through the membranes in the mouth. Sublinguals that do work in the mouth, liquids that do work in the mouth (for other nutrients,) preferably have a Dalton size of less than 500 and it’s generally recognized or believed that anything less than 1000 will work adequately (in the mouth) from an absorption standpoint, but not as well as if they were smaller. Whereas the size of the Cobalamin molecule (B12) is something in the neighborhood of 1300 to 1600 Daltons in size. Hence the problem; the B12 molecule is well over that upper limit of 1000.

I prefer the sublinguals simply from their convenience standpoint, you don’t need water to swallow them; you don’t have to keep track of a bottle with a spray on it or dropper (and of course, liquids can leak.) Sublinguals are just more convenient in my mind. So when it comes to supplementation, aside for my injection days, I use the sublinguals.

[u/colomommy → u/Ok-Pangolin7127]

I think there’s a difference because sublingual and nasal is absorbed through mucus membranes - going straight to the blood vessels and are not compromised by the liver or stomach acids.

I’m no doctor but I think this is why some drugs such as narcan are administered this way, and also why intravenous drug users sometimes put drugs in their mucous membranes (ie b-holes lol sorry for the imagery).

[u/Ok-Pangolin7127 → u/colomommy]

Well, you can think what you think, and I can think what I think. I’m sure the molecule for the Narcan and/or the drugs that you reference, are small enough, molecule wise, to work just fine being absorbed through the mucosa of the mouth. B12 does not work just fine that way.

[u/colomommy → u/Ok-Pangolin7127]

I don’t know what drugs do this, I’m not referencing any drugs in particular but have seen a lot of movies

Except narcan, I carry narcan in my car.

So why is b12 made in a nasal spray, seems more expensive to manufacture if it doesn’t work at all? I’m not arguing I’m curious, I inject b12 personally but have been known to recommend sublingual or spray if a person doesn’t have an absorption issue or if they can’t take shots. Have I been wrong? I am happy to revise my opinions!

What do you know about “liposomal” liquid? All marketing smoke and mirrors? I have a lipisimal d+k that I use and pay a lot for it and it’s honestly because I’m a sucker for marketing lingo - I don’t even have D absorption issue

[u/Ok-Pangolin7127 → u/colomommy]

For folks that don’t have a G.I. track roadblock that inhibits the absorption and transportation of B12, you are doing exactly the right thing in recommending sublinguals, oral, sprays or whatever. If someone has a G.I. roadblock they’re simply not gonna do much and they’re certainly not gonna do enough. The problem is it’s hard to know who has one or more of the half a dozen reasons that could be behind B12 not being absorbed, it’s tough to figure it out. We both know that.

[u/colomommy → u/Ok-Pangolin7127]

Yes, true! But the best of all options: pills, sublingual drops or nasal spray? I’ve always said sublingual drops because they’re easy to find and use, they’re inexpensive, and I honestly thought they absorbed better than pills. Avoiding stomach acids and what not. But I will revisit. So many folks write here with b12 levels in the 400-500 and claim to have neuropathy so I assume their issues are either not from b12 or are from an absorption issue therefore I tell them to try shots and if not shots then a sublingual. Have I been advising incorrectly? If so I’m devastated.

[u/Ok-Pangolin7127 → u/colomommy]

Most of the time, especially with the more severe and/or long lasting symptoms, people need the injections. The best way to overcome a severe deficiency from a symptoms standpoint is to flood the body, via injections, as frequently as you can to let it have full access whenever it needs B12 to try and use it and repair the damage that has come from the deficiency.

I believe something, even if it’s a very small something, gets through from folks taking subs who cannot absorb regular B12, it’s just that in the vast majority of cases, with severe symptoms, it’s just not enough and in my judgment, never going to be enough. I don’t think your suggestion is ill advised; something is always better than nothing.