What B12 Supplement Should I Take?


What B12 Supplement Should I Take?


I get this question all the time, so I finally decided to write up a blog post to point people to.


Cyanocobalamin is the most common form of B12 supplement and is the form found in fortified foods. It doesn’t occur much in nature, but it is the most stable form of vitamin B12, and the cheapest. It has been the most studied form and has consistently been shown to be effective. Unless there are extenuating circumstances, I recommend that people take cyanocobalamin as their B12 supplement.

Cyanocobalamin contains a molecule of cyanide, but the amount of cyanide in cyanocobalamin supplements is so small as to be physiologically insignificant (more info).

Some people have cyanide metabolism defects, and they should not take cyanocobalamin. If you are asking yourself right now if you might be one of those people, you can assume the chances are close to zero.

People with cyanide poisoning should not take cyanocobalamin. If you have not previously suspected that you might have cyanide poisoning, then you can assume you don’t have it.

People with chronic kidney problems should probably take a non-cyanocobalamin form of B12 (more info).

Finally, cigarette smokers might want to take a non-cyanocobalamin form of vitamin B12 as they can build up cyanide in their system. This is theoretical – I have never come across a vegan cigarette smoker who reported vitamin B12 deficiency based on taking cyanocobalamin and the Institute of Medicine has concluded that “The effect of smoking on the B12 requirement thus appears to be negligible (1).” (More info.)

Methylcobalamin & Adenosylcobalamin

Methylcobalamin is one of the two co-enzyme forms of vitamin B12, the other being adenosylcobalamin (known by many other names, including “dibencozide”). When I first got into the B12 issue, dibencozide was all the rage, now it’s methylcobalamin for some reason. The two forms have different functions in the body and both are necessary (more info).

Methylcobalamin is promoted by some alternative health practitioners and the supplement industry as superior to cyanocobalamin, primarily because it is a co-enzyme form of vitamin B12.

Based on many studies and case reports in the scientific literature in which cyanocobalamin has successfully cured vitamin B12 deficiency, it appears that the body can convert cyanocobalamin into methylcobalamin without any problem. The body also has to convert methylcobalamin or cyanocobalamin into adenosylcobalamin for B12 to carry out all of its functions. (A fourth form of vitamin B12, hydroxocobalamin, is the form typically found in animal products and B12 injections; it must also be converted into the co-enzyme forms.)

But is there any harm in taking methylcobalamin over cyanocobalamin? Probably not, but methylcobalamin is thought not to be as stable as cyanocobalamin and therefore higher doses are recommended, a minimum of 1,000 µg per day. Recommendations for cyanocobalamin are much lower (more info).

Some people with chronic fatigue report getting more relief from adenosylcobalamin than either methylcobalamin or cyanocobalamin (more info), while other people report feeling better only when taking both co-enzyme forms (adenosyl- and methyl-).

Cyanocobalamin supplements are ubiquitous, cheap, and well-studied, while methyl and adenosyl are much more of an unknown entity. Unless you have a good reason to be using them, I recommend cyanocobalamin.

Living Food Vitamin B12

Some companies claim to have a natural, living, plant, or raw source of vitamin B12. The B12 can come from seaweed or other unstated sources. Unless a label lists the source of vitamin B12 as cyanocobalamin, methylcobalamin, adenosylcobalamin, or hydroxocobalamin, I would not rely on it.

Specific Brands of Vitamin B12

I do not have recommendations regarding any specific brands of vitamin B12 supplements. As far as cyanocobalamin goes, I assume all sublingual or chewable tablets to be effective. I do not have an opinion on B12 skin patches or sprays.

As far as methylcobalamin supplements, as I stated above, I’m not as confident about them, and I have no opinion on any specific brand name.

Are B12 Supplements Vegan?

Yes. (More info.)


1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.

78 Responses to “What B12 Supplement Should I Take?”

  1. Troy Says:

    Hi Dr Norris,

    Thanks for this valuable resource, and this useful information (and for your book 😉

    Do you have any recommendations for infants and babies? None of the common multivitamins (say Pentavite) contain any B12. They all have an incredibly strong flavor – I’ve also tried Metagenics Multicare for Kids but the taste is so strong I can’t get it into my kid.

    So I’ve resorted to grinding up a small amount of a regular sublingual B12 tablet, sticking it on the end of my finger and poking that into his mouth. He doesn’t mind this 🙂

    Thanks again!

  2. Jack Norris RD Says:


    The link in the post to the B12 recommendations gives amounts for all ages. You can mix the B12 in with your son’s food. What country are you in, btw? I’ve never heard of a multivitamin not containing vitamin B12.

  3. Troy Says:

    Thanks, Jack, for the reply – sorry, my question was vague 🙂 my query is actually if you knew of a particular form that is usable for infants.

    I am in Australia. Since my wife is non-caucasian, she was mildly low in vit D, so health service here suggest Pentavite (http://www.bayer.com.au/scripts/pages/en/bayerrsquos_products/index.php?aktion=details&id=349&l1=Bay) It’s easy to apply as a liquid with a little plunger to squirt into the mouth. It has a rather stark saccharine orange flavor, but it’s usable, but as mentioned, no B12. I did not find an alternative in a similar form.

    A naturopath/nutritionist at my local health store suggested Multicare for Kids (http://www.metagenics.com.au/products/multi-care-kids-170-g-powder-orange-flavour), which comes in a powder form, intended to mix with water, suggesting I mix it into some food. Again it has a rather intense orange flavor, so I can get away with some of it in mango, but can’t really get much of it into him. (After tasting it, I can’t blame the little guy!)

    He is eating solids and still breastfeeding, so I know he should be well covered, but obviously I want to be doubly sure. I put a little Vitashine D3, a little Opti3Omega in food, which is easily masked, and the crushed tablet for B12. I have been putting nutritional yeast in some things too. I may go back to the Pentavite for other coverage. I think this is about the best solution now.

  4. michael Says:

    Wow, I was literally just getting ready to purchase this: http://store.veganessentials.com/vegan-vitamin-b-12-spray-by-nutrasumma-p3221.aspx for myself and my nearly 3 year old child when I flipped tabs to read this article. The product has all three forms of b12 in it. Sorry for asking you to “hold my hand” through this, but do you think such a product would be fine for usage by my small child?


  5. Jack Norris RD Says:


    Obviously, if you read my post, you should know that I don’t think anything but cyanocobalamin is necessary. Here is a link to the amounts of B12 I recommend for people of various ages:


    The supplement in question contains more than I recommend for 3-year olds for a daily dose. However, the only known harm from high dose vitamin B12 supplements are rare cases of acne-like symptoms that resolve upon ceasing the high doses.

    I make a point of not telling people what products they should buy to meet the recommendations I give. In this case, the product meets my recommendations and then some.

    I hope that helps.

  6. Dave Says:

    Thank you for this great summary.

    I’m coming up on 5 years of eating vegan, and just a few weeks ago I bought methylcobalamin for the first time, after years of exclusive cyanocobalamin B12 supplementation.

    I was lured in by the slick marketing text! Thank you for the reality check. My old routine was apparently more than sufficient!

  7. Rochelle Says:

    I read that some nutritional yeasts are sufficient for B12. Is this so?

  8. Jack Norris RD Says:


    See this link:


  9. Ilene Says:

    I read that cyanocobalamin was not a good idea if you have kidney problems. Can you comment?

  10. Jack Norris RD Says:


    I should have mentioned that. I’ll add it to the article. Here is more info:


  11. Rochelle Says:

    Thank you that was helpful. Been vegan since May and relying on RedStar nutritional yeast for B12 plus multivitamin. I believe I have much better nutrition now as I never paid attention b4, and now I must. Let alone benefits to animals and planet. But thx for sharing your knowledge. I appreciate your contribution.

  12. Michelle Says:

    My supplement says “Vitamin B12 (as cobalamin)” – no methyl, cyano, or anything else. What the heck does THAT mean?

  13. Jack Norris RD Says:


    As long as it doesn’t come from a “natural”, “living”, “raw”, or “plant” source, it is probably cyanocobalamin and is fine. If it comes from any of the sources I mentioned in quotes, I wouldn’t rely on it.

  14. Konstantinos Says:

    Hello Jack,

    I would like to ask about Minimal Risk Level for oral cyanide. I ‘ve read the reference 7.

    Opinion of the Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (AFC) on hydrocyanic acid in flavourings and other food ingredients with flavouring properties. The EFSA Journal (2004) 105.

    At bullet 21, says than the dietary recommended intake is 12μg/kg which is mush lower than the 0,05mg/kg.

    Which limit should we use?

    What’s your opinion?

    Thank you.

  15. Konstantinos Says:


    The bullet of the statement is 27

  16. Jack Norris RD Says:


    Is looks like they consider .05 mg/kg to be the limit for what humans should ingest on a daily basis. See bullet 29.

  17. Konstantinos Says:

    Thank you Jack for your answer,

    I ‘ve purchased your book and I am reading it carefully.

    It’s a great, great, great book!

    Congratulations for your work.

    Greetings from Greece.

  18. jd Says:

    Your opinions (and that’s all they are) on methylcobalamin fly in the face of many studies on it. Do your research people, he is wrong!

  19. Jack Norris RD Says:


    If you know of some actual peer-reviewed clinical trials comparing methylcobalamin to cyanocobalamin that you can cite to show I’m wrong, I’d be happy to see them. I don’t know of any myself. If methyl- is better than cyano-, then I’d be happy to embrace methyl-. I couldn’t care less which is better, but I want proof, and a “Do your research” statement is less evidence than what I’m basing my opinion on.

  20. Marek Says:

    Somebody asked me if he should worry about cyanocobalamin supplements he’s just bought because he “has kidney cysts but hasn’t seen a nephrologist for a few years and feels fine”.

    I’m wondering how much I should stress the advice to avoid cyanocobalamin if someone has kidney problems. Is it a real threat or is it just that it might be better to take other forms but nothing to be seriously worried about? You wrote in another article that the cyanid intake from cyanocobalamin is insignificant compared to other sources, so why should it worry kidney patients – do they also need to limit other sources, or is cyanid from cyanocobalamin somehow more risky for them?

    The problem is also that methylcobalamin supplements are not easily available in my country as far as I know…

  21. Jack Norris RD Says:


    If someone isn’t having ongoing kidney filtration issues, then I don’t see a reason to worry much. But definitely don’t take more than is recommended.

  22. Marek Says:

    OK. Thanks. But I’m still wondering – if cyanide intake from fruits and vegetables (which I assume are still eaten by kidney patients) can range between 95 and 372 micrograms per person – which you wrote here http://jacknorrisrd.com/safety-of-cyanide-in-cyanocobalamin/ – why should the additional 2 micrograms per day (from 100 mcg cyanocobalamin – you wrote there’s 20 in 1000) be significant? Or are kidney patients advised to only eat low-cyanide fruits and vegetables?

  23. Jack Norris RD Says:

    > Or are kidney patients advised to only eat low-cyanide fruits and vegetables?

    People on dialysis or very low kidney function have to limit fruit and vegetables due to potassium, but I don’t know what their average cyanide intakes are.

  24. Darayas Mistry Says:

    I have a friend who’s child has a B12 deficient kid who is 3.5 yrs old and gets convulsion attacks very frequently. Can U suggest foods with B 12 contents we are from India where in we do not have a greater excess to food supplements.

  25. Jack Norris RD Says:


    It sounds like the child needs to be taken to a mainstream health professional if at all possible. Animal products have vitamin B12 and plants don’t. I would not know how you can obtain B12 fortified foods or supplements in your area other than to order them online from a reputable source.

  26. Kathy Malcolm Says:

    Dear Jack, great info. thanks.
    does there seem to be any difference between the cheaper generic drug store brands vs the more expensive “health food store” brands, ie Solgar, or the like. ie does the quality vary if you pay $3/100 tabs, vs $10 per 60 tabs?

    I was looking at one site, that said that for a single oral dose of 1000mcg cyanocobalamin
    1.3% or 13 mcg is absorbed.
    but for injection of 1000mcg 15% or 15mcg is absorbed.
    that seems to be saying that the best route for absorbtion is injection.

    3rd question: if a person is B12 deficient, why not use BOTH oral and injection so as to increase the amount absorbed each day and increase the levels more quickly?

    Thank You, Kathy

  27. Jack Norris RD Says:


    > does there seem to be any difference between the cheaper generic drug store brands vs the more expensive “health food store” brands, ie Solgar, or the like.

    I have no reason to believe so.

    Yes, injections are a better route than oral, but unless you can’t absorb B12, there’s no reason to get them unless you are in a dire situation.

  28. Im Says:

    Hello, thanks for this post, really interesting.

    I just took part in a study monitoring the effects of B12 levels on homocysteine. As part of it I took a B12 cynacobalamin supplement for 7 weeks and completed a food diary.

    At the end of the study my homocystiene levels were significantly lower, and so the study scientist recommended that I supplement with methylcobalamin rather than cynacobalamin. However, having just read your article above I’m unsure whether I need to, and whether Methylcobalamin is ok as a supplement.

    Do you think it is safe to take both cynacobalamin and methylcobalamin? The methyl supplement I have is 500mcg daily (Advantage B12 spray) , the cyna supplement (Veg 1) is 10mcg daily.

    Hopefully the study will be published in the next year or so and will help inform the debate.

  29. Jack Norris RD Says:


    > At the end of the study my homocystiene levels were significantly lower, and so the study scientist recommended that I supplement with methylcobalamin rather than cynacobalamin.

    If you lowered your homocysteine level using cyanocobalamin, why is the study scientist suggesting you need methylcobalamin?

  30. Nicci Says:

    What type of b12 can be used for weight loss?

  31. Jack Norris RD Says:


    B12 has little or nothing to do with weight loss. I recommend cyanocobalamin as the most reliable form of B12 for most people, and it shouldn’t affect weight loss.

  32. Adam Says:

    Hi, I’ve found this page by searching for which form of B12 I should take. Before I read it, I was sure that I would be taking methylcobalamin or adenosylcobalamin. Because I don’t know the conversion rate of cyanocobalamin, I figured it would be a safer bet to ingest the active form directly. Also, I would prefer not ingesting a source of cyanide willingly.

    Reading your article makes me feel somewhat safer. However, I would like to point this study on the safety of using methylcobalamin and adenosylcobalamin instead of cyanocobalamin:

    It has found no safety concern on these 2 forms.

    I would like to hear your thoughts about it.

  33. Jack Norris RD Says:


    I won’t be convinced until I see a study in which small amounts of methylcobalamin reduce MMA levels.

  34. Susan Says:

    Hello Doctor,
    I am suddenly cold in my legs and arms been like this for 9 days I am having pins and needles in my feet too, not to bad but there. Does this sound like it could be a vitamin B12 deficiency. How much would I normally take I am a 57 year old female.

  35. Jack Norris RD Says:


    If you are vegan, I recommend the following to replenisih vitamin B12 stores: http://veganhealth.org/b12/rec

    If you do not see improvement after a week, you should see a doctor (which might not be a bad idea regardless).

    If you are not vegan, then I would highly encourage you to see a doctor about this problem.

  36. stanley Says:

    All the supplements on the market contain very high doses of B12 per tablet. I just want to take about 50-100mcg per day. What should I do?

  37. Jack Norris RD Says:


    Break them in smaller amounts.

  38. Alocasia Says:

    I gave up beef and pork 5 years ago, and dairy and the rest 2 years ago since I’ve been a plant based vegan.. I have been taking methylcobalamin for over 5 years now. I switched to methyl for a few reasons…one the talk of the cyanide, and two, I had a diabetic cat, and the methylcobalamin cured her neuropathy (she was able to walk well again) where the cyan B12 that she was on for a very long time did nothing.

    My blood test shows my B12 level at 970. The range is 200-1100. Can you have too much B12? I thought it was water soluble, and the excess is passed.

  39. Jack Norris RD Says:


    The only side effects that I’m aware of that can come from too much B12 are acne-like symptoms.

  40. Alocasia Says:

    Thanks so much for responding..

    Do you know offhand if B12 can affect essential fatty acid results in a blood test? Any idea where I can go to find out why many results are off the chart high and I eat nothing for my omega 6’s, 3’s, DHA or EPA to be so high?

  41. Jack Norris RD Says:


    B12 would not have anything to do with that. What are your results, and where did you get them measured?

  42. Alocasia Says:

    I was having my bi-yearly lipid and basic bloodwork done at a local lab and had the EFAs done as well as my homocysteines. Other than the lipid panel and basic metabolic panel, these were recommended to me by a vegan group. I have a copy of my numbers that I typed up. Is there a way to attach it here or email it to you?

  43. Jack Norris RD Says:


    I’ll send you an email.

  44. Pat Burt Says:

    Hello Doctor.

    I am a smoker 15/20 a day. What type of vitamin B12 should I be taking safely.
    My doctor says I do not need this, but after one injection I felt a new person, an new lease so life an have been unwell for some years. She is telling me it’s in the mind, an given me anti depressants. I know I do not need this. Just B12. But I am a smoker, please which type should I take. Thank you so much.

    Pat Burt

  45. Jack Norris RD Says:


    For heavy smokers, I would suggest methylcobalamin at 1,000 µg per day.

  46. stacy lundblad Says:

    I have MTHFR A1298C and other genetic mutations with detox and digetstion, COMT, CBS, MOA-A, etc. When i take my methylfolate I need B12 but I get ill from taking it. I have tried methylcobalamin, and hyroxycobabalim and both make me very ill with a burning mouth. Could be I am taking too much and my body cant detox that fast. I know I have mercury and other metals to get out but the detox of the liver isnt strong enough right now to do it. Methyalation pathways are broken right now so lots of organic acids out of balance…HIGH range. What kind of B12 is best for me?

  47. Jack Norris RD Says:


    That’s not my area of expertise, I’m afraid I don’t know.

  48. Jeff Says:

    Hi Jack,

    I was looking at your B12 recommendations on veganhealth.org and I’ve got a dosage question. Right now I have 500mcg tablets and I’ve been taking one of these three times per week (MWF). Does this seem like a reasonable strategy, or should I double up and take them twice a week so I hit your recommended 1000mcg twice weekly recommendation?


  49. Jack Norris RD Says:


    500 µg three times a week should work just as well.

  50. Thalia Says:

    What would you recommend as a B12 supplement for my son, who is 5 years old and on a PPI (15 mg lansoprazole) and therefore has lowered stomach acid and is not absorbing what he should be. He has been on the PPI for over a year now. Is there a sublingual vitamin or a spray that you would recommend that is safe for a five year old, and is methylcobalamin preferable in this case? Is there anything else you would supplement with? We are pescatarian (we eat dairy and fish but no other animals i.e., no cow, chicken, pig, etc.).

  51. Jack Norris RD Says:


    This question should be addressed by his doctor. But I’m not aware of sublingual B12 pills being dangerous for children, I have not seen any research measuring the effects of sprays, and I would see no reason why methylcobalamin would be preferable.

  52. Ann Says:

    My nerves all over my body feel as though they are ready to explode. And I get so angry because I’m always on edge. My doctor says my B levels are not low enough to take a B supplement. But my tongue and my sore mouth say different. I dont know what to do. I pray for healing of these nerves. And my memory has been horrible. Can u give me some advice.

  53. Jack Norris RD Says:


    I’m sorry to hear about your problems, but giving advice about situations like yours isn’t what I do. You might want to get a second opinion from another doctor.

  54. Karl Baba Says:

    The reason for Methylcobalamin is that some people have genetic polymorphisms of genes like MTR, MTRR and others which inhibit the conversion of cyanocobalmin to active forms. People with these genetic variations are also the most likely to be deficient so, in my opinion, better to use Methlcobalamin if you don’t know your genetic status

  55. Jack Norris RD Says:


    Do you have any evidence from research in humans that people with these polymorphisms require methylcobalamin? This is the first I’ve heard of it.

  56. Sandra Says:

    Dear Jack,
    I have been transitioning to a vegan diet over the past year and was taking a B complex supplement irregularly. Over the past 2 months I cut out all animal products and was taking a B complex supplement almost every day. The supplement I was previously using had cyanocobalamin, 150mcg. I ran out and switched to “coenzyme b-complex caps” with 500mcg. After taking these for under two weeks I broke out in really terrible acne that took a couple of weeks to resolve. I now realize that the dosage was much higher with this supplement and also it was methylcobalamin. I am wondering if acne has been linked specifically to methylcobalamin? I am asking because I might try taking this one again (I have a whole bottle left) but only twice a week to reach your dosage recommendation. Otherwise, if there is reason to believe methylcobalamin could be the problem, then I will switch back to cyanocobalamin. Also, is there any reason it might be better to take a lower dose daily instead of a higher dose every few days? Thanks!!

  57. Jack Norris RD Says:


    My recommendations are for cyanocobalamin only. For methyl- I recommend 1,000 micrograms per day. If you think this is giving you acne, I would try cyanocobalamin in much smaller doses on a daily basis, probably from fortified foods.

  58. Sandra Says:

    Thank you, Jack. I decided to go with a B complex that had 100 mcgs of cyanocobalamin, which I will take daily. Hopefully that will keep the zits at bay!

    I read your related post and comments on this topic, which was very helpful.

  59. M. Tiver Says:

    I know this is an old post but hopefully you’ll see this. Is it true that folate/folic acid and b12 should be taken together? Lots of websites seem to say it’s important to stop them hiding a deficiency of each other, like in this article – http://www.methylcobalamininfo.com/vitamin-b12-and-folic-acid-whats-the-connection/. So are they just trying to make me buy more stuff or what’s the deal?

  60. Jack Norris RD Says:

    M. Tiver,

    If you’re vegan, there’s no need to take folic acid unless you are considering getting pregnant. Most vegans get plenty of folate from their diet.

  61. Gina Says:

    Sorry doc but I think your old school! Why on earth would anyone want to take a cyanocobalamin when they can take a better co factor like adenl or methyl. And 50% of the world has one or more copies of the MTHFR gene and consuming cyan does nothing for this gene. And to suggest to get your vitamins from fortified food? Yikes!

  62. Rochelle Says:

    Gina, did you read the blog post at the top of this thread? JN answers that issue, and frankly between JN and you, as a vegan, I’m listening to credentials and so to JN. No dis intended.

  63. Alan Says:

    Hello Dr Norris
    Thanks for your article. I’m considering buying cyanocobalamin liquid because it seems to be the purest form (tablets and sprays seem to all have added ingredients other than purified water). Are the dosage recommendations different for liquid as opposed to tablet? Is it best to drink the liquid drops with a little water or to put the drops under the tongue? I’m thinking about optimum absorption.
    Thank you in anticipation of your reply.

  64. Jack Norris RD Says:


    I’m not aware of any research on liquid vitamin B12. I see no reason why the dosage would be different and sublingual is probably no better than swallowing:


  65. Xavier Says:

    Hello Dr,

    Do you recommend a higher daily intake for endurance athletes? I’m a new vegan, currently taking 1000 mcg methyl- daily. I will have a blood test in a few months but wonder if you are aware of athletes requiring higher dosages to increase it in the meantime.

  66. Jack Norris RD Says:


    Vitamin B12 needs are thought to be the same for athletes, but I doubt they’ve been tested in any rigorous way.

  67. Katya Says:

    Hello Jack!
    I am currently taking Solgar cobalamin 1000 mcg. Dors it mean cyano or I am taking a wrong form?

  68. Jack Norris RD Says:


    It’s cyano, which is the default “cobalamin’. If it were another form, they’d say so.

  69. Angela Says:

    I assume you are not familiar with mthfr and comt? I cannot take cyanocobalamin and because of the variants with the comt I’m methyl intolerant… Do you know which is better between the other two?

  70. Jack Norris RD Says:


    I have not seen evidence of vitamin B12 forms being dependent on the MTHFR or COMT enzymes. But I’m not an expert in that area by any means.

  71. Jack Norris RD Says:


    I’m not aware of genetic defects in MTHFR or COMT (which I presume you’re suggesting you have?) determining which type of vitamin B12 someone should take.

  72. Jonathan Says:

    Hi Jack I’m trying to find a recommended dosage for hydroxycobalamin it seems to be the only sub lingual I am able to tolerate.

    1000mg daily? Or would 1000mg twice a week suffice?

    Thank you!

  73. Jack Norris RD Says:

    Hi Jonathan,

    It’s really hard to say. I’d probably take it 3 times per week to be on the safe side.

  74. Anders Says:

    Hi Jack,

    I accidently bought a B12 supplement in (rice based) capsules rather than chewable tablets.

    Can I use them instead of chewable tablets? Perhaps by opening the capsules and swallowing the powder? Or would it be best to discard the capsules and get some chewable tablets instead?

  75. Jack Norris RD Says:


    Only people who think they don’t have strong enough digestion to break pills down need to chew them. To be safe, I recommend everyone chew them, but most people don’t need to. So I’d use up the capsules before getting new B12 unless you think your digestion tends not to break down capsules or tablets. Opening them and dumping into a glass of water would also work.

  76. Diana Howell Says:

    First let me say…THANK YOU!!! I started seeing a Naturopath who convinced me that I should never, ever take Cyanocobalamin, only Methylcobalamin – that it is far more superior for my health issues. Needless to say, I switched over immediately – but after several months still didn’t notice any improvement in my peripheral neuropathy. At this point he had me start taking methyl drops, and methyl tablets, and a weekly methyl B12 IV drip. After almost a year of incredible expense (oh…did I neglect to mention that he sold all these methyl products in his office?), I’ve gone back to the over-the-counter Cyano B12 daily tablets – happy to know from your writings that there is no discernible difference. Wish I had found you thousands of dollars ago! Thank you, again!

  77. Z Says:

    Hi Jack,

    There is a newer review comparing B12 supplements and it seems that all forms work equally:


    Chalmers8 reviewed the results of 3 human studies that also found lower tissue retention of B12 as a result of supplementation with CNCbl rather than OHCbl, MeCbl, or AdCbl, together with increased urinary excretion of CNCbl. The researchers concluded that the lower bioavailability of CNCbl was due to its lower efficiency in cellular uptake and metabolic activation. Other researchers are concerned about cyanide accumulation in human tissues from long-term intake of CNCbl from supplements and/or fortified foods.2,9 Thus, it seems that the CNCbl is an inferior choice for use in nutritional supplements or injections of B12. In fact, a Lancet review has proposed the discontinuation of CNCbl because OHCbl had been made available, and owing to concerns regarding the cyanide moiety, especially for smokers.10

  78. Jack Norris RD Says:

    I reread the Chalmers paper and it didn’t provide new information regarding the effectiveness of one oral form of B12 being better than another. In fact, it reinforced the view that when taken orally, there’s no evidence of one form being better than another. My latest writings on the various forms of B12 can be found in the article Methylcobalamin and Adenosylcobalamin. A recent, detailed article I wrote on concerns regarding the cyanide portion of cyanocobalamin is Vitamin B12 and Cyanide.

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