Sublingual B12 no better than just swallowing

Question (edited for clarity):

It is always explicitly recommended that Vitamin B12 tablets should be dissolved under the tongue (aka “sublingual”). I wonder if that is also true for other minerals and vitamins of special concern to vegetarians, such as iron and vitamin D2? If not, why is this the case with vitamin B12?

Answer:

I have always told people who asked about sublingual B12 that there was no evidence, of which I was aware, that sublingual was any better than just chewing. Despite this, until today, I had been recommending sublingual in my Step 1 Recommendations, which are geared towards people who have not recently had a reliable source of B12. I have recommended sublingual as a precaution just in case it was more effective. In recent years, I have been more diligent about trying not to recommend anything just to be prudent unless specifically stating that is why I am recommending it. This suggestion for sublingual (versus just oral) was a remnant left over from previous times.

Still, I did not know whether sublingual was better than oral until I got this question and decided to check in on the research. As it turned out, there was a study as long ago as 2003. Yikes! I guess I hadn’t checked in quite a long time.

The 2003 study compared 500 µg per day via the sublingual and oral routes. The results were that sublingual was absolutely no better than oral B12 at raising vitamin B12 levels or improving B12 activity (as measured by homocysteine and methylmalonic acid levels). The report did not specifically state whether the tablets were chewed or not (I assume that they were swallowed whole). So now I’m not sure I should even suggest that the tablets be chewed, but because other studies have shown a benefit to chewing, I will leave that in my recommendations.

As for other vitamins and minerals, I have never checked into the research on taking them via the sublingual route, but my sense is that there would not be any benefit. It might even be dangerous to try this with iron given that it is a pro-oxidant and probably should not be held in constant contact with your tissues.

Reference

Sharabi A, Cohen E, Sulkes J, Garty M. Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. Br J Clin Pharmacol. 2003 Dec;56(6):635-8. | link

48 Responses to “Sublingual B12 no better than just swallowing”

  1. Renata Says:

    Does it matter if we choose cyanocobalamin or methylcobalamin?

  2. Jack Norris RD Says:

    The study was done on cyanocobalamin, but I have no reason to think methylcobalamin would be any different.

  3. rick Says:

    I have long been under the impression that B12 sublingual administration was superior to to swallowing because it bypassed the digestive process and was absorbed directly into the bloodstream. I also thought that B12 sublingual absorption was equivalent to B12 injections. I have been passing this on to numerous people on a plant-based diet.

    Are you saying that there are no studies that support my contentions, or that one study refutes it? Are B12 injections superior?

    I have also read that an intrinsic factor is required to absorb B12 via swallowing, and that some lack this factor–another reason to administer sublingually. But on the other hand, I have also read that it is instead B12 deficiency that causes the loss of the intrinsic factor.

    Any studies yet on B12 transdermal patches? They tout superior absorption.

    Thanks!

  4. Heather Nauta Says:

    This is a great post Jack, something I hadn’t looked into and am so glad you put up here! It now makes a lot of sense to me why those vegans who tried sublingual to correct a deficiency with no results had to turn to injections – or worse, thought that they needed to turn to animal foods.

  5. mar Says:

    I don’t understand the reasoning in the second to last paragraph. If other studies show benefits with chewing, wouldn’t that benefit be had via sublingual dissolution too? If not, what could be the difference?

    Sidenote: where I live (europe) sublingual B12 wasn’t so easy to find. I’ve never seen it available at a physical pharmacy and had to buy it through an online store at a higher price than oral B12 (though both are still pretty inexpensive).

  6. Jack Norris RD Says:

    Rick,

    > Are you saying that there are no studies that support my contentions, or that one study refutes it?

    I am saying both. I don’t know of any other studies on the subject and this one was fairly convincing.

    > Are B12 injections superior?

    Oral B12 of 2,000 µg per day has been shown to be just as effective as B12 injections. You can read more about that here:

    http://veganhealth.org/b12/formula

    1 to 1.5% of B12 is absorbed through passive diffusion and doesn’t require intrinsic factor.

    > Any studies yet on B12 transdermal patches? They tout superior absorption.

    I’m sure they do. I don’t now of any studies, but I haven’t gone looking.

  7. Jack Norris RD Says:

    Heather,

    > It now makes a lot of sense to me why those vegans who tried sublingual to correct a deficiency with no results had to turn to injections

    I maybe should have been more clean in my post. Oral B12 was effective at raising B12 levels, as was sublingual. It’s just that sublingual was not more effective than sublingual. As I said to Rick regarding his comment, 2,000 µg of B12 per day, orally, has been shown to be just as effective as injections. I don’t know how much B12 the people you know of were taking, though, so maybe they weren’t taking enough.

  8. Jack Norris RD Says:

    mar,

    Okay, I see where I’ve caused confusion. When I said this:

    “The results were that sublingual was absolutely no better at raising vitamin B12 levels or improving B12 activity…”

    I meant this:

    “The results were that sublingual was absolutely no better *than oral B12* at raising vitamin B12 levels or improving B12 activity..”

    Now does it make sense? I’ll make that addition to my post.

  9. mar Says:

    Jack, no because I was/am confused by the statement on chewable. You wrote:

    “The results were that sublingual was absolutely no better than oral B12 at raising vitamin B12 levels or improving B12 activity (as measured by homocysteine and methylmalonic acid levels). The report did not specifically state whether the tablets were chewed or not (I assume that they were swallowed whole). So now I’m not sure I should even suggest that the tablets be chewed, but because other studies have shown a benefit to chewing, I will leave that in my recommendations.”

    I read that as saying:
    - all three sublingual, chewable and swallow whole are adequate for B12 intake
    - previously we thought there was extra benefits with sublingual and chewable over oral (swallow whole)
    - now we think sublingual is no better than oral
    - but chewing still has a “benefit”

    That seems to entail that chewable is better than both sublingual and oral. Which seemed puzzling to me. How could chewing bring extra benefits that sublingual dissolution doesn’t? The two studies (no extra benefit with sublingual vs extra benefits with chewing) sound inconsistent to me.

  10. mar Says:

    Jack, not quite. I read the post as saying:
    1. a new study give evidence that sublingual and oral are equally good (both being adequate modes of B12 intake).
    2. another study give evidence that chewable has extra benefits over oral.

    Those two pieces of evidence together seem to entail that chewable has extra benefits over sublingual too. I was puzzled over how that could be, given that both involve breaking the B12 pill down to smaller particles while in the mouth.

  11. Heather Says:

    Jack – yes, I did understand that what you were saying in your post was that sublingual was no more effective than oral at the same dose. I think it was me who wasn’t clear… What I’ve seen is that people were taking an oral dose, then took the same, or slightly higher (1000 mcg) as a sublingual and didn’t see results, so they turned to injections. So exactly what you suggested – the problem was that they weren’t taking enough, but they thought the problem was a failing of the supplement since they were told sublingual should have been more effective than their regular oral form. And until reading this post, I would have agreed! I would have tried taking a higher dose of sublingual myself, but I would have also looked into injections – and I certainly wouldn’t have gone back to straight oral doses.

  12. Jack Norris RD Says:

    mar,

    Okay, I see what you mean.

    Maybe it would help if I pointed you to my write-up about the study that found that some (but not all) B12-deficient vegans could not raise their B12 levels without chewing the supplements:

    http://veganhealth.org/b12/vegansources#CHEW

    Based on the results of the two studies, it seems that some B12 tablets are much easier dissolved in the digestive tract than others (for some, but not all, people – or maybe for some, but not all vegans?).

    It *is* possible that chewing is better than both swallowing whole and sublingual for some reason that is not obvious (perhaps the B12 gets too degraded in the mouth if it sits there for a long time?). But my money is on the suspicion that the tablets used in the 1994 study were harder to dissolve than those in the 2003 study.

  13. Edward Says:

    Hello Jack. I take NOW’s “ultra b-12″ 5000mcg oral solution (1 teaspoon) daily. Is liquid B-12 as effective as tabs? Thanks for your awesome work.

  14. Jack Norris RD Says:

    Edward,

    > Is liquid B-12 as effective as tabs?

    I don’t know of any research but I have no reason to think it wouldn’t be just as effective as tablets.

  15. Lori Says:

    Hi Jack, Due to what I’ve been reading by you about B-12, and being a 30-year vegan, I just had a homocysteine level test. It came out 4.8. Everything I read starts at a level 5. What does 4.8 mean? Love your work!

  16. Jack Norris RD Says:

    Lori,

    Sounds like you have excellent homocysteine levels. Congratulations.

  17. Ninufar Says:

    Sorry to be late to this topic, but if you’re still responding to comments here, I’d like to ask:

    Does this post suggest that pregnant vegans can skip the injunction to only rely on sublingual or chewable B12 in your (very helpful) supplement summary in your book, Vegan For Life?

    I’m very interested in this question, bc every sublingual and chewable B12 supplement I’ve checked into (about a dozen) contains sweeteners which I can’t digest too well. If I’m successful in getting pregnant, I’ll have enough digestive challenges to deal with without piling sorbitol reactions on top of that. I take the Deva Vegan Multi, additional D, and a liquid cal/mag supplement.

    Thanks again for all your work to clear away the hype and the false information standing between vegans/near-vegans and good health!

  18. Jack Norris RD Says:

    Ninufar,

    Eating B12-fortified foods twice per day should be just fine.

  19. Ben Says:

    Wait a minute this post is confusing me. I have a medically induced B12 deficiency, I am not a vegan or vegetarian I purely just have a problem and I came here looking for some answers but found a shallow discussion, though maybe I’m just wrong or perhaps this site is ONLY meant for vegans/vegetarians that have B12 deficiencies and that is is not meant for actually B12 deficient patients with complications.

    The sublingual tablets are made for people with B12 deficiencies caused by genetic or health factors (and subsequent disability to produce intrinsic factor via loss of gastric parietal cells). The reason there are two methods is not because one is better or worse, and for all the people that are getting caught up in this, the only reason I take sublingual over oral is because it is IMPOSSIBLE for me to get b12 oral compared to sublingual.

    You should only have an interest in sublingual if you do not like swallowing or you have a metabolic disorder (like me) that causes many b12 deficiencies in omnivores.

    The fact that a study revolves around which one is better is almost sad considering the genesis of either was made in consideration to the medical circumstance, not whether one or the either was more effective. That is what concentrations are for, to mediate the transfer of proteins via diffusion.

    Maybe this is only for vegetarians, but you should know in any case that you shouldn’t be concerned over whats better, just do what you prefer. If I could, I would definitely take oral since the sublingual looks kind of like guts in my mouth lol.

  20. Jack Norris RD Says:

    Ben,

    1. This site is intended for vegetarians and vegans.

    2. The study highlighted here was conducted both on vegetarians/vegans and on people with abnormal B12 absorption determined by a Schillings Test. As the authors say, “There was no significant difference in cobalamin concentrations between the subjects with a normal and abnormal Schilling test.” So it appears that sublingual is no better than oral for people with B12 absorption problems.

  21. Donna Says:

    I’ve been vegan for 13 years, and take a multi-vitamin/mineral supplement that contains B12. Lately I had been dragging myself around, too tired to get things done in the evening, not able to concentrate, etc. I ordered some liquid B12 and wow, what a difference! I just turned 55 and feel like 35 again.

    So I wonder about the B12 that is supposed to be in the multi-vitamin tablet (100 mcg once a day). Or maybe I just needed a megadose (1,200 mcg twice a day).

  22. Jack Norris RD Says:

    Donna,

    I’m (very) surprised that 100 mcg wasn’t enough to prevent an overt B12 deficiency which it sounds like you were starting to get. Did you have any tingling in your fingers or toes? How long had you been taking 100 mcg per day from the tablet and how consistent were you?

  23. Donna Says:

    I’ve been taking this particular brand of multivitamin everyday since 1/2011. I don’t recall any tingling in toes or fingers.

  24. Jack Norris RD Says:

    Donna,

    That’s very strange. But I’m glad you figured out you needed more.

    You might have a defect for producing intrinsic factor, aka “pernicious anemia”. People with PA need large doses of vitamin B12.

  25. Donna Says:

    That makes sense — I have had Hashimoto’s for several decades and this page says it raises my risk for PA: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001595/

  26. gaurav Says:

    hi!! i was diagnosed with b12 deficiency with a level of 85. i started taking 5oo mcg of injections every alternate day.i felt better for few days but after 6 injections i am again feeling very weak and tired with depression. i feel i will never be fine again. my doc says it’ll take time to heal. he prescribed total of 10 injections after that pills.. should i consult another doctor. how can i find whether i’ve pernicious anemia or not. i’m 22 and also a vegetarian. is such low level due to any thing else?? pls reply.i’ll be very greatful.

  27. Jack Norris RD Says:

    gaurav,

    The test for pernicious anemia is a Schilling’s Test, and it is not uncommon, so you might want to talk to your doctor about it. I would suggest that you just keep monitoring your symptoms with your doctor. If the injections are not working, then your doctor needs to figure out what else could be wrong.

  28. gaurav Says:

    @jack
    my doc says it’s all psychological problem because after 10 injections symptoms due to vit b 12 deficiency should go away. how long can it take to recover full?. he asked me to make dietry correction. as i said i feel tired and weak specially in legs.i feel urge to stretch my legs and body frequently also my bones make sometimes when i move my legs or body. can there be any other deficiency other than b 12? like vit d3 or sumthng? it’s very crucial time ofmy life so i’m very worried. i keep constantly thinking abt my illness and that results in tension and depression with sumtimes fear and rapid heartbeat.i.e. anxiety

  29. Jack Norris RD Says:

    gaurav,

    How long it should take for a full recovery will vary from person to person, but 10 injections should have resulted in significant improvement.

    Vitamin D deficiency sounds consistent with many of your health problems. You should talk to your doctor about other reasons for your problems, or find a new doctor.

  30. JL Norris Says:

    @Jack,

    Following an accident resulting in serious nerve damage, one of my doctors wrote a script for 2500 mcg of B12 daily. He cited studies showing positive development in nerve regeneration. I’ve been religiously taking it since that time. I can’t say if its the reason for improvement since there are other factors and regrowth of nerves happens at a snail’s pace anyway.

    A few months ago, an acquaintance who learned of this and also must take B12 told me I should be very careful to look for B12 with Methylcobalamin rather than Cyanocobalamin so as to truly get the benefit. This week my travels got extended so I had to stop at a drug store to have enough supplies to make it through the rest of the stay. I couldn’t find any of the B12 offering Methylcobalamin, so I asked the pharmacist about it. He asked for my reasons, what I take, and then proceeded to tell me that pretty much everything on the other side of the counter did nothing more than produce expensive urine.

    I’d appreciate your thoughts on Methylcobalamin vs. Cyanocobalamin, and any studies you can point me to read for greater understanding. Also, any feedback on the pharmacist’s comment?

    Thanks, j

  31. Jack Norris RD Says:

    JL,

    Nice last name!

    I normally don’t think there’s any need to take methylcobalamin and it presents some problems (instability) that cyano- doesn’t have. Here is my write-up on it:

    http://veganhealth.org/b12/noncyanob12

    Once your nerves have regenerated you can probably cut way back on the B12, but talk to your doctor first.

  32. panos Says:

    hi jack i was vegan for 2.5 years and i tested for b12 two months ago my level of b 12 is 86 and my doctor gave me five injections for five days back to back and now one every month for six months and then ill be tested again but iam on second month and no serious improvment can i take between the shots any supplement of b 12?what you think for sprays b12 (methylcobalamin) ?is there any problem between injections and oral b12?i mean if the oral can affect the shots?sorry for my english thanks anyway.

  33. Jack Norris RD Says:

    panos,

    I don’t think it would hurt to take 1,000 µg per day. I’d choose chewable cyanocobalamin tablets over methylcobalamin, unless you are a smoker. If you smoke, I’d take more like 2,000 µg of methylcobalamin. I don’t know how well sprays works, so I’d tick with chewable tablets.

  34. Allan Shuman Says:

    I can’t imagine why there is all this talk about swallowing B12 when injectable is so readily available and is very easy to administer to yourself.

  35. rick Says:

    I believe that most people prefer oral administration of anything to injections if efficacious.

  36. Mark Says:

    This is an interesting topic that I have been looking into for some time
    My wife a 35 year strict vegetarian was found B12 deficient 15 months ago her blood level was 162
    Her symptoms have been on-going for 4 -5 years, but became much worse last year
    She suffers daily with extreme fatigue, burning hands and feet white skin patches, vision and cognitive impairment,
    She did decide to eat some meat again but has discovered that she can no longer tolerate or digest it without much bloating and discomfort
    After her diagnosis she started on Jarrow methycobalamin 5000mcg 2- 3 daily, within a few weeks her blood level was up to 2000, great we thought just a few weeks and her symptoms should subside!
    15 months later she is no better, maybe even even slightly worse, it appears that the b12 in her blood is either not enough to remedy the problem or it is not actually available to be used where it is needed in her body
    This is an interesting topic but fails to make any meaningful sense as to the requirement to rectify long term deficiencies, it appears that those who just want protection from low b12 can pretty much use anything to keep toping up reserves, but once those bodily reserve have been depleted and damage has occurred it’s a whole new ball game to remedy.
    We are about to try patches hopefully these will give a more controlled and steady b12 release
    Unbelievably her GP has never offered to give her any b12 injections on the basis that her blood levels are now sufficient.

  37. Jack Norris RD Says:

    Mark,

    I’m really sorry to read that. I would not assume that B12 deficiency is her problem – you should try to rule out other things if you can, possibly see a neurologist.

    You might also try cyanocobalamin for a few days to see if that works any better. I don’t know why it would if her B12 levels went to well above normal (the same thinking that your doctor is apparently having about injections), but it seems worth a try. Maybe the methylcobalamin is inactive analogues…

    Keep me posted and feel free to contact me privately: http://jacknorrisrd.com/contact_form.php

  38. reppac Says:

    nice post, but as pointed out in some comments, it only cover cyanocobalamin.

    This is used in supplements for two main reasons. Damn cheap, and greater stability in the gut before absorption. As a result, more is available to be absorbed by the body, so has a roughly equal rating with sublingual.

    The Methyl version however is less stable so by the time it reaches lower intestine for absorption, there is not much left, so sublingual methyl works much better than standard oral.

    Additionally cyanocobalamin is converted in the body to methylcobalamin and adenosylcobalamin, leaving behind cyanide which has to be cleaned up by the body and removed.

    In summary: on a simple level B12 is just as good swallowed as sublingual, but high quality B12 (methyl) is more effective sublingually and better for you anyway.

  39. Jack Norris RD Says:

    reppac,

    That’s interesting and I’d like to know if it’s true. Do you know of any scientific research that backs it up?

  40. Laury Says:

    This article says “methylcobalamin is not absorbed well from the stomach, which is why vitamin products contain cyanocobalamin.”
    So they made a study: methyl-B12 is better absorbed by injection or through the nose than sublingual.
    http://www.greatplainslaboratory.com/home/eng/b12.pdf

    I conclude then cyano-B12 can be absorbed as we wish, but we have to be more careful for the methyl-B12.

  41. Jack Norris RD Says:

    Laury,

    > methylcobalamin is not absorbed well from the stomach, which is why vitamin products contain cyanocobalamin.

    Although I don’t know for sure, I don’t see why that would be, and to my knowledge it’s not why vitamin products contain cyano. Rather, they contain cyano because cyano is a much more stable form.

  42. reppac Says:

    Jack,

    there is a lot of info there drawn in from a number of sources, but a good starting point is the following article which gives the process of converting the cyano into a useful version for the body:

    Pezacka E, et al Glutathionylcobalamin as an intermediate in the formation of cobalamin coenzymes. Biochem Biophys Res Commun 1990;169(2):443-50.

  43. Jack Norris RD Says:

    reppac,

    Thanks for the citation. I was thinking more along the lines of a clinical trial showing this to be the case. Piecing this info together via animal studies is one thing, but actually showing it in a trial in humans is much more reliable.

  44. BenC Says:

    This comments thread appears to have great longevity so I’ll offer my question. I understand the contention the sublingual is no better than oral in terms of raising overall levels however does sublingual have any advantage in terms of speed of absorption? To me this gets to the real heart of the issue – which is, is sublingual absorption actually happening at all or are we just dissolving then swallowing with no direct-to-bloodstream effect? In terms of B12 this may be an irrelevant point but I actually arrived on the topic as I was interested in the effect of chewable vs sublingual melatonin, where speed of action is a factor.

  45. Jack Norris RD Says:

    BenC,

    I have seen no studies on this question in humans.

  46. Jack Norris RD Says:

    For anyone following this thread, I’m not putting any comments through saying that sublingual is better unless they provide reasonable evidence to back up their claim. I am getting commenters who I believe to be merely trolls trying to promote sublingual B12.

  47. cj Says:

    Jack, that study Laury posted basically showed the sublingual methylcobalamin did nothing. Correct? I was always curious if perhaps my sublingual b12 lozenges which dissolve in under 5 seconds even gave enough dissolve time to permeate the membrane of the tongue. Any thoughts? The study she posted is quite alarming.

  48. Jack Norris RD Says:

    cj,

    That PDF Laury linked to is not exactly a peer-reviewed study and I wouldn’t worry about it. My thoughts are that swallowing is just as good as sublingual.

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