For prevention and treatment of vitamin B12 deficiency, cyanocobalamin in chewable, sublingual, or liquid forms (rather than in a multivitamin) is best under most circumstances.
The Best Type of Vitamin B12: Cyanocobalamin or Methylcobalamin?
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Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
I’ve talked about the optimal dose of vitamin B12 supplements for adults, as well as in childhood, pregnancy, and old age to prevent vitamin B12 deficiency. But what if you already have it? How much do you have to take to treat it?
Your doctor might want you to get vitamin B12 injections, but oral B12, even for those who can’t absorb it well, has long been considered one of medicine’s best kept secrets. It is now considered well-known that orally administered B12 supplements are “as effective in overcoming deficiency states as intramuscular” injections when you get up to taking 1,000 micrograms a day. How long do you have to take 1,000 a day for? It depends how low your levels start out.
Because B12 status in pregnancy is so critical, there is a suggestion that plant-based women get it checked throughout pregnancy and to adjust supplementation as necessary. This is how much you should take if you’re low. Note the recommendations for pregnant and breast-feeding women are the same as everyone else over the age of 10. So, if you’re a teen or adult diagnosed with vitamin B12 deficiency, you’d take 1,000 micrograms a day for one to four months, depending on how low you start out, before going back to a regular maintenance dose of 50 a day or 2,000 a week, with toddlers and small children taking smaller doses.
There are two main types on the market, though: methylcobalamin, marketed as methyl B12, and cyanocobalamin, typically marketed as just vitamin B12. Methyl is more expensive so it must be better, right? Wrong. Cyanocobalamin “is the most used form due to its high stability.” See, “methylcobalamin is less stable than cyanocobalamin, and it is particularly susceptible to photodecomposition,” meaning destruction from being exposed to light. “There is no advantage to using the light-sensitive forms of cobalamin, such as methyl B12…, instead of the stable cyano…forms, which are readily converted in the body” into the type you need, where you need it.
The one major exception may be kidney failure, though. Methylcobalamin may be better for those with impaired kidney function. It’s been speculated that oral methylcobalamin or injected hydroxycobalamin may also be preferable in smokers, though it has yet to be confirmed. Because methylcobalamin is less stable, you’d probably want to take much higher doses. So, for example, in those with kidney failure you’d be taking one to two thousand micrograms a day, compared to just 50 micrograms of cyanocobalamin in someone with normal kidney function. Another reason to use the cyanocobalamin as opposed to the more expensive kinds is that it has a track record of safety and efficacy, whereas for example, in one study even up to 2,000 micrograms a day of methylcobalamin wasn’t enough to correct vitamin B12 deficiency in one of three vegans they tested it on.
The bottom line is that so-called coenzyme forms of B12, like methyl B12 and adenyl B12 (also known as adenosyl b12), “are not likely to be superior to cyanocobalamin,” which is more stable. Cyanocobalamin “appears to be best suited for oral supplementation,” which is why I specify its use in my recommendations.
Note I also recommend ideally taking it separately as a chewable, sublingual, or liquid supplement. Why can’t you just get it as part of a multivitamin or something? Because various vitamins and minerals mixed into the same pill can “destroy” active B12, forming B12 analogues, B12-look-alikes that not only can our body not use, but the analogues can be “potentially harmful” because they can inhibit the transport of what little B12 is left. That’s why using multivitamins can even be counterproductive for the supplementation of vitamin B12. And this isn’t just in theory. There was a tragic case of severe vitamin B12 deficiency in an infant born to a vegan mother who thought she was doing everything right taking a multivitamin that contained B12, though it may have also just been inadequate dosing.
Why chewable or sublingual? Absorption is boosted when the B12 mixes with saliva, since you secrete a B12 binding protein from your salivary glands that helps transport B12 safely through the digestive tract. Having people chew a tablet of B12 and their B12 levels go up ten times more than just simply swallowing the exact same pill. Check it out. Vegans boosted out of deficiency chewing a B12 supplement, but nothing in those who just swallowed it whole. Maybe they had some sort of absorption problem or something? No, because then if you tell them to start chewing it instead of swallowing it whole, their levels shoot right up as well.
In my latest book How Not to Diet, I suggest a third option to B12-fortified foods and supplements—brushing twice daily with a B12-fortified toothpaste—specifically this brand, which was put to the test in two double-blinded, randomized, placebo-controlled studies. “Participants were instructed to use the toothpaste two times a day for two minutes at a time,” and indeed, it was able to correct the markers of B12 insufficiency in the blood of vegans and among the elderly, but that was on average. Unfortunately, it didn’t work in every last person, which is why it’s not included in my recommendations. Though, look, if you get your levels tested before and after brushing for a few months and they go up, you could presumably stick with it.
In summary, vitamin B12 deficiency is not to be messed around with, with the potential to cause a wide range of disorders of the gut, blood, brain, and nervous system. “With the ever-increasing demand for cleanliness in our food chain”—which is a very good thing—”it is of special importance that we secure” a regular reliable source, and the safest, cheapest, healthiest source is B12 supplements or green light B12-fortified foods.
Please consider volunteering to help out on the site.
- Lederle FA. Oral cobalamin for pernicious anemia. Medicine's best kept secret?. JAMA. 1991;265(1):94-5.
- Alpers DH. Another indication for the use of oral vitamin B-12 supplementation. Am J Clin Nutr. 2018;108(1):1-3.
- Wang H, Li L, Qin LL, Song Y, Vidal-alaball J, Liu TH. Oral vitamin B versus intramuscular vitamin B for vitamin B deficiency. Cochrane Database Syst Rev. 2018;3:CD004655.
- Baroni L, Goggi S, Battaglino R, et al. Vegan Nutrition for Mothers and Children: Practical Tools for Healthcare Providers. Nutrients. 2018;11(1)
- Rizzo G, Laganà AS, Rapisarda AM, et al. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016;8(12)
- Mariotti F, ed. Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press; Cambridge, MA, USA: 2017.
- Green R, Allen LH, Bjørke-monsen AL, et al. Vitamin B deficiency. Nat Rev Dis Primers. 2017;3:17040.
- Hankey GJ. B vitamins for stroke prevention. Stroke Vasc Neurol. 2018;3(2):51-58.
- Rizzo G, Laganà AS, Rapisarda AM, et al. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016;8(12)
- Spence JD. Metabolic vitamin B12 deficiency: a missed opportunity to prevent dementia and stroke. Nutr Res. 2016;36(2):109-16.
- Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab. 2000;44(5-6):229-34.
- Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res. 2015;59(7):1364-72.
- Kondo H, Binder MJ, Kolhouse JF, Smythe WR, Podell ER, Allen RH. Presence and formation of cobalamin analogues in multivitamin-mineral pills. J Clin Invest. 1982;70(4):889-98.
- Guez S, Chiarelli G, Menni F, Salera S, Principi N, Esposito S. Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy. BMC Pediatr. 2012;12:85.
- Crane MG, Sample C, Patchett S, Register UD. Vitamin B12 Studies in Total Vegetarians (Vegans). J Nutri Med. 1994;4(4):419-30.
- Siebert AK, Obeid R, Weder S, et al. Vitamin B-12-fortified toothpaste improves vitamin status in vegans: a 12-wk randomized placebo-controlled study. Am J Clin Nutr. 2017;105(3):618-625.
- Zant A, Awwad HM, Geisel J, Keller M, Obeid R. Vitamin B12-fortified toothpaste improves vitamin status in elderly people: a randomized, double-blind, placebo-controlled study. Aging Clin Exp Res. 2019;31(12):1817-1825.
- Briani C, Dalla torre C, Citton V, et al. Cobalamin deficiency: clinical picture and radiological findings. Nutrients. 2013;5(11):4521-39.
- Greger M. 2019. How Not to Diet. New York: Flatiron Books.
Video production by Glass Entertainment
Motion graphics by Avocado Video
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
I’ve talked about the optimal dose of vitamin B12 supplements for adults, as well as in childhood, pregnancy, and old age to prevent vitamin B12 deficiency. But what if you already have it? How much do you have to take to treat it?
Your doctor might want you to get vitamin B12 injections, but oral B12, even for those who can’t absorb it well, has long been considered one of medicine’s best kept secrets. It is now considered well-known that orally administered B12 supplements are “as effective in overcoming deficiency states as intramuscular” injections when you get up to taking 1,000 micrograms a day. How long do you have to take 1,000 a day for? It depends how low your levels start out.
Because B12 status in pregnancy is so critical, there is a suggestion that plant-based women get it checked throughout pregnancy and to adjust supplementation as necessary. This is how much you should take if you’re low. Note the recommendations for pregnant and breast-feeding women are the same as everyone else over the age of 10. So, if you’re a teen or adult diagnosed with vitamin B12 deficiency, you’d take 1,000 micrograms a day for one to four months, depending on how low you start out, before going back to a regular maintenance dose of 50 a day or 2,000 a week, with toddlers and small children taking smaller doses.
There are two main types on the market, though: methylcobalamin, marketed as methyl B12, and cyanocobalamin, typically marketed as just vitamin B12. Methyl is more expensive so it must be better, right? Wrong. Cyanocobalamin “is the most used form due to its high stability.” See, “methylcobalamin is less stable than cyanocobalamin, and it is particularly susceptible to photodecomposition,” meaning destruction from being exposed to light. “There is no advantage to using the light-sensitive forms of cobalamin, such as methyl B12…, instead of the stable cyano…forms, which are readily converted in the body” into the type you need, where you need it.
The one major exception may be kidney failure, though. Methylcobalamin may be better for those with impaired kidney function. It’s been speculated that oral methylcobalamin or injected hydroxycobalamin may also be preferable in smokers, though it has yet to be confirmed. Because methylcobalamin is less stable, you’d probably want to take much higher doses. So, for example, in those with kidney failure you’d be taking one to two thousand micrograms a day, compared to just 50 micrograms of cyanocobalamin in someone with normal kidney function. Another reason to use the cyanocobalamin as opposed to the more expensive kinds is that it has a track record of safety and efficacy, whereas for example, in one study even up to 2,000 micrograms a day of methylcobalamin wasn’t enough to correct vitamin B12 deficiency in one of three vegans they tested it on.
The bottom line is that so-called coenzyme forms of B12, like methyl B12 and adenyl B12 (also known as adenosyl b12), “are not likely to be superior to cyanocobalamin,” which is more stable. Cyanocobalamin “appears to be best suited for oral supplementation,” which is why I specify its use in my recommendations.
Note I also recommend ideally taking it separately as a chewable, sublingual, or liquid supplement. Why can’t you just get it as part of a multivitamin or something? Because various vitamins and minerals mixed into the same pill can “destroy” active B12, forming B12 analogues, B12-look-alikes that not only can our body not use, but the analogues can be “potentially harmful” because they can inhibit the transport of what little B12 is left. That’s why using multivitamins can even be counterproductive for the supplementation of vitamin B12. And this isn’t just in theory. There was a tragic case of severe vitamin B12 deficiency in an infant born to a vegan mother who thought she was doing everything right taking a multivitamin that contained B12, though it may have also just been inadequate dosing.
Why chewable or sublingual? Absorption is boosted when the B12 mixes with saliva, since you secrete a B12 binding protein from your salivary glands that helps transport B12 safely through the digestive tract. Having people chew a tablet of B12 and their B12 levels go up ten times more than just simply swallowing the exact same pill. Check it out. Vegans boosted out of deficiency chewing a B12 supplement, but nothing in those who just swallowed it whole. Maybe they had some sort of absorption problem or something? No, because then if you tell them to start chewing it instead of swallowing it whole, their levels shoot right up as well.
In my latest book How Not to Diet, I suggest a third option to B12-fortified foods and supplements—brushing twice daily with a B12-fortified toothpaste—specifically this brand, which was put to the test in two double-blinded, randomized, placebo-controlled studies. “Participants were instructed to use the toothpaste two times a day for two minutes at a time,” and indeed, it was able to correct the markers of B12 insufficiency in the blood of vegans and among the elderly, but that was on average. Unfortunately, it didn’t work in every last person, which is why it’s not included in my recommendations. Though, look, if you get your levels tested before and after brushing for a few months and they go up, you could presumably stick with it.
In summary, vitamin B12 deficiency is not to be messed around with, with the potential to cause a wide range of disorders of the gut, blood, brain, and nervous system. “With the ever-increasing demand for cleanliness in our food chain”—which is a very good thing—”it is of special importance that we secure” a regular reliable source, and the safest, cheapest, healthiest source is B12 supplements or green light B12-fortified foods.
Please consider volunteering to help out on the site.
- Lederle FA. Oral cobalamin for pernicious anemia. Medicine's best kept secret?. JAMA. 1991;265(1):94-5.
- Alpers DH. Another indication for the use of oral vitamin B-12 supplementation. Am J Clin Nutr. 2018;108(1):1-3.
- Wang H, Li L, Qin LL, Song Y, Vidal-alaball J, Liu TH. Oral vitamin B versus intramuscular vitamin B for vitamin B deficiency. Cochrane Database Syst Rev. 2018;3:CD004655.
- Baroni L, Goggi S, Battaglino R, et al. Vegan Nutrition for Mothers and Children: Practical Tools for Healthcare Providers. Nutrients. 2018;11(1)
- Rizzo G, Laganà AS, Rapisarda AM, et al. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016;8(12)
- Mariotti F, ed. Vegetarian and Plant-Based Diets in Health and Disease Prevention. Academic Press; Cambridge, MA, USA: 2017.
- Green R, Allen LH, Bjørke-monsen AL, et al. Vitamin B deficiency. Nat Rev Dis Primers. 2017;3:17040.
- Hankey GJ. B vitamins for stroke prevention. Stroke Vasc Neurol. 2018;3(2):51-58.
- Rizzo G, Laganà AS, Rapisarda AM, et al. Vitamin B12 among Vegetarians: Status, Assessment and Supplementation. Nutrients. 2016;8(12)
- Spence JD. Metabolic vitamin B12 deficiency: a missed opportunity to prevent dementia and stroke. Nutr Res. 2016;36(2):109-16.
- Donaldson MS. Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic supplements. Ann Nutr Metab. 2000;44(5-6):229-34.
- Obeid R, Fedosov SN, Nexo E. Cobalamin coenzyme forms are not likely to be superior to cyano- and hydroxyl-cobalamin in prevention or treatment of cobalamin deficiency. Mol Nutr Food Res. 2015;59(7):1364-72.
- Kondo H, Binder MJ, Kolhouse JF, Smythe WR, Podell ER, Allen RH. Presence and formation of cobalamin analogues in multivitamin-mineral pills. J Clin Invest. 1982;70(4):889-98.
- Guez S, Chiarelli G, Menni F, Salera S, Principi N, Esposito S. Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy. BMC Pediatr. 2012;12:85.
- Crane MG, Sample C, Patchett S, Register UD. Vitamin B12 Studies in Total Vegetarians (Vegans). J Nutri Med. 1994;4(4):419-30.
- Siebert AK, Obeid R, Weder S, et al. Vitamin B-12-fortified toothpaste improves vitamin status in vegans: a 12-wk randomized placebo-controlled study. Am J Clin Nutr. 2017;105(3):618-625.
- Zant A, Awwad HM, Geisel J, Keller M, Obeid R. Vitamin B12-fortified toothpaste improves vitamin status in elderly people: a randomized, double-blind, placebo-controlled study. Aging Clin Exp Res. 2019;31(12):1817-1825.
- Briani C, Dalla torre C, Citton V, et al. Cobalamin deficiency: clinical picture and radiological findings. Nutrients. 2013;5(11):4521-39.
- Greger M. 2019. How Not to Diet. New York: Flatiron Books.
Video production by Glass Entertainment
Motion graphics by Avocado Video
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Title
The Best Type of Vitamin B12: Cyanocobalamin or Methylcobalamin?
LicenseCreative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)
Content URLDoctor's Note
Whoa, that video was packed to the hilt. The dosage needed to treat B12 deficiency, how oral is better than injectable, why the cheaper form (cyanocobalamin) is superior to the more expensive form (methylcobalamin), why you can’t just take it in a multivitamin because of the analogs, and you shouldn’t just take it in a pill you just swallow (because it needs to mix with that saliva protein), and then with the toothpaste thing totally coming out of left field.
I mentioned my book, How Not to Diet, which you can find out more about here. It’s funny how I said it was my “last” book, not aware at the time I recorded it that little did I know I’d have a whole new book out by then out of nowhere. How to Survive a Pandemic, out now in softcover, audiobook (read by me), and e-book form.
This is the last in a five-part video series on B12. You can find all of these videos in a digital download here, along with two additional videos that will be coming out in a few months on the potential for B12 side-effects.
If you missed any in this series, check out:
- The Symptoms of Vitamin B12 Deficiency
- The Optimal Vitamin B12 Dosage for Adults
- Healthiest Food Sources of Vitamin B12
- The Optimal Vitamin B12 Dosage for Kids, Pregnancy, and Seniors
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