Vitamin B12 and the Case For (and Against) a Plant-Based Diet

Fresh salad bowl

The other day, Jeff D. asked some great questions in the comments section of my post 10 Things I Wish I Knew Before I Went Vegan:

What are your thoughts concerning the inability to get B12 naturally on a vegan diet? It’s necessary for the body but a vegan diet only seems to get B12 through fortified foods and supplements.

Also, what about grains? It seems that a vegan diet relies on a lot of grains (bread, pasta, cereal, etc.). Recent research and acknowledgement of our anthropological history point to the idea that our bodies were not meant to process grains (especially gluten-based ones).

Grains are a topic for another post (check out The Paleo Diet Debunked?, by my friend Steve — a Paleo proponent but whose view on grains is almost identical to mine).

Right now, let’s stick to the B12 question; it’s a common one. Often, it takes a more argumentative and challenging tone, like this:

If we were really meant to be vegan, then why would we need to supplement with B12?

There’s little doubt about the presupposition: a vegan diet, without B12 supplementation or fortification, is deficient in vitamin B12. Some will argue that you can get B12 from chlorella or “dirty produce,” and that before modern agricultural practices there was more B12 in the soil, but that’s not the discussion I want to have here.

My assumption in this post is that you can’t get B12, in the necessary amount, from a vegan diet unless you supplement or eat fortified foods. So …

How can one say we’re meant to be vegan?

My answer to this question often surprises the person asking me, and it might surprise you, too: I don’t think we’re “meant” to be vegan.

If there’s anything we’re meant to do, from an evolutionary perspective, it’s “reach reproductive age and have kids that do the same.” On whatever diet our environment affords us.

And, you must admit, our bodies are pretty remarkable in their ability to do this — to survive, and often thrive, on a huge range of diets.

Just look at how many people eat the Standard American Diet — it’s called “standard” for a reason. Anyone who thinks about their food agrees that the SAD is horrible, yet most people who eat that way don’t have any problem living long enough to have kids and to care for those kids until they’re old enough to care for themselves.

Less extreme: look at pro athletes, and what a vast range of diets they have. Whether in endurance sports, mainstream sports, Olympic sports, or combat sports, you can find someone on top of the world eating whichever diet you’re searching for. Paleo, vegan, fruitarian, fast food … you name it, someone (in a relatively small pool of elite athletes) is doing it.

The criteria for deciding which diet is best

So meant is a confusing term. Is the diet that maximizes longevity the one we’re “meant” to eat? Or is it the one, say, that makes us perform the best in sports, or the one that gives us six-pack abs?

Most of us aren’t pro athletes or even serious athletes. We do the sports we do in order to enrich our lives, but that’s it. And abs, well, we know you can have those for three easy payments of $19.99, and they’ll even throw in some Mighty Putty. So we’ll leave that be.

For me, and I suspect most other people, longevity is what we’re after.

Let’s look at the question from that perspective: What populations of people live the longest, and what do they eat?

Dr. Joel Fuhrman devotes a small section in his excellent book Super Immunity to this question. And his answer is:

The longest-lived societies in history — such as the Hunzas in central Asia, the Abkhazians in southern Russia, the Vilcambans in the Andes of South America, and the Okinawans in Japan — all ate very little animal products but were not completely vegan. As we drift considerably up from the occasional use of animal products, to include animal products in significant amounts, we see evidence that more heart disease and most cancers become more prevalent.

Of course, the source Fuhrman cites for this last assertion is T. Colin Campbell’s famous China study (not the book but the study itself), one that has drawn criticism, like many longevity studies, for mistaking correlation for causality. (Namely: people who choose plant-based diets tend already to make healthier choices, making it tougher to determine whether it’s the diet or their healthy lifestyle in general that is responsible for their longevity.)

But Fuhrman later describes the Adventist Health Studies, which were designed so as not to make this causation/correlation mistake. The population studied, the Seventh Day Adventists, is almost completely free of alcohol and tobacco use and lives a nearly uniformly healthy lifestyle, with one exception: half are vegetarian, and half eat small amounts of meat.

As it turns out, the study found that the vegetarians lived longer than those who ate small amounts of meat, but other factors like whether or not someone ate nuts and seeds actually had a larger effect on longevity than whether that person was vegetarian or near-vegetarian.

But back to B12 …

So if the healthiest populations in history have mainly eaten diets that include a small but (importantly!) nonzero amount of meat, what does that tell us?

To me, it says our bodies our great at thriving on plants, but there’s something in animal products that we need and can’t get elsewhere without supplementing. And that something is what we know as B12.

So the question remains:

If B12 is the only reason we used to need meat, and we can now supplement with B12 and avoid meat entirely, do we maximize health by doing so?

Studies like the Adventist Health Study, mentioned above, point to “yes,” but still with some hesitation over causality versus correlation. But the differences between a vegan diet and a near-vegan diet appear to be tiny, so tiny that I think they can be ignored (when it comes to health, not ethics, of course).

Even pro-vegan Dr. Fuhrman actually believes that a 100% vegan diet can result in “suboptimal levels” of other nutrients, like DHA, EPA, iodine, and zinc. But eating more animal products as a way to get these nutrients leads to increased heart disease and cancer rates, according to his research.

(This is why I like Dr. Furhman’s work, by the way. He avoids dogma and doesn’t let ethical leanings color his understanding and advice about health  — I’m not even sure what his ethical stance on veganism is. When a scientist can’t admit a single fault of his or her diet of choice, that sounds an awful lot like religion to me.)

For me, the take home message, and (finally) my answer to Jeff’s question, is:

I believe that a diet with a very small amount of animal products, like what we see in the diets of the longest-lived societies, is extremely healthy. It’s clear that we need B12, and if there were no other way to get B12, then in general, I would consider a diet with a lot of plants and a very small amount of meat to be the healthiest possible type of diet.

Fortunately, for those of us with ethical reasons for wanting to avoid animal products, we can now do so healthily, by supplementing with B12. I haven’t seen any good evidence that a plant-based diet of mostly whole foods, along with a B12 supplement, is less healthy than any other diet — some studies show that a vegan diet might actually be healthier than a whole-food based diet that includes a tiny amount of meat, but to me it’s not clear that the difference is significant.

Jogger resting at beach

Whole foods, mostly plants

Eat whole foods, eat lots of plants, and whether you choose to eat a small amount of meat or not won’t make much difference in the healthfulness of your diet.

Ethically, it makes a dramatic difference, and that’s why I choose to be vegan. But arguing about whether a whole-foods based diet that includes a small amount of meat is healthier than a whole-foods, plant-based diet seems to me like a waste of time, when other factors make a bigger difference in health — like nuts and seeds in the Adventist Health Study, for example.

Worse, the argument unnecessarily widens the gap between whole-food vegans and whole-food omnivores. We’re both in the healthy minority, and I wish we’d embrace that instead of quibbling over whose diet is healthier. Again, that’s not to say there aren’t ethical grounds for disagreement, but if that’s what the argument really comes down to, don’t pretend it’s about health.

If you agree — and I’m well aware that many people don’t — a good place to start is with these two posts, one by me and one by Steve Kamb at Nerd Fitness. They’re written in much the same vein, just from opposite sides of the vegan/Paleo line.

1. Why Paleos and Vegans Should Stop Hating Each Other

2. The Paleo Diet Debunked? (Jeff and anyone else wondering what I think about grains, I agree with Steve’s take on them)

As always, I’m interested to hear your comments. I may not like arguing, but I learn something whenever I write a post like this and people chime in from different sides.



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  1. So…What about nuts and seeds? Please, the suspense is too much!

  2. Eliot W. Collins says:

    Anyone can have a B-12 deficiency, and the only way to know for sure is to get tested.

    If one does have a deficiency, then take a B-12 supplement. Cyanocobalamin is pretty harmless.

    It is as simple as that.

  3. Clyde Grubbs says:

    B12 is synthesised in the intenstines of mammals, (including humans.) It is also in the soil from mammals leaving bowel deposits.

    Because of anti biotics “civilized humans” don’t produce enough. It is available as a supplement in many foods.

    • It’s synthesized in human bowels, but farther down the digestive tract than where it is absorbed. It could be synthesized as well in the human mouth of people who don’t brush their teeth, but that’s not a reliable (or socially acceptable) source!

  4. I think the thing that is missing from this is that meat doesn’t have B12. It’s the bacteria in the meat that produces B12 and therefore the bacteria’s production of B12 is passed on to you when you eat meat. However, a lot of meat eaters have low levels of B12 and many vegans have adequate levels of B12. (good info here from Dr. McDougall –

    Our own guts actually have bacteria in them that synthesize B12 too. The reality is that in our current lives, everything is overly washed, sterilized, etc. So even if you eat meat, you can still be lacking in B12. If you eat vegetables that you grow out of your own organic garden and don’t scrub them and wash them to death, then you probably will get B12 that way. But we are now very “germ” conscious.

    So I don’t the the argument holds that we aren’t supposed to be vegan because of B12. Way before civilization got so “germ” crazy, there were probably many people who were vegan who never took a B12 supplement. But we are paranoid about germs now.

    B12 is especially important in older adults as many are deficient, no matter what they eat. I’d still rather eat a 100% plant based diet which I know is better for my health, than to eat meat to try to get some B12. I’ll pop a supplement under my tongue a few days a week instead not only for my health, but to save animals and the environment.

    • Great response, Karen.

    • Veggiemom66 says:

      I hear you! I am not a germaphobe at all…I am waayyyy too lax about washing fruits and veggies. The problem is that I am wrong for being so lax…. animal production (can’t really call it husbandry) has too much run-off that contaminates the soil is the cause for things like e-coli outbreaks from spinach. I agree with Matt’s basic premise: whole foods, lots of veggies, a bit of meat/fish probably is as healthy as vegan diet (I mean, that is what the world Blue Zones eat) BUT humans are so adaptable….time to “evolve” away from being primitive (cruel) meateaters.

      • You have to be kidding! Run off !! In the United States that contamination especially E-coli comes from field workers who poop in the field rather than stop to get to a toilet to go! They make their money on production and that means filling as many tubs, baskets etc. with what ever produce is being harvested as quickly as possible! Americans are so far removed from where their food actually comes from it’s ridiculous! Most harvesting of fruits and vegetables is done by migrant farm workers not citizens of the USA. Those people are looking for a better life and come here to make money. The same applies to produce harvested in Mexico, middle and South America. A small amount of some strains of pathogens make their way into the food chain by way of untreated water used to irrigate farm land where produce is grown. Getting rid of junk food and fast food would do more to nourish our world than we can imagine!

    • Thank you for the info about B12…a fog just cleared in my head!

    • We are softer than our ancestors. We now do need to wash plants before consumption. It isn’t about being a germaphobe. I’m not saying to not live life, have human contact, etc. Chemicals, even organic has some, and feces can make humans sick. Sometimes it’s a deadly illness and sometimes it just lessens quality of life. If one doesn’t eat fortified foods then take a supplement. Even some meat eaters are lacking in vitamin B12 because they are lacking the enzymes in the gut to process it. Pills then won’t help. Lozenges and tinctures, even shots in some cases, are then necessary.

    • David Springer says:

      I am not eating dirty produce. Thank the industrial world of supplements for making your diet possible.

  5. Brenna McEowen says:

    Incredibly well-said!

  6. I love having a plant based diet. I also continue to have between 1-3 eggs per week. Usually at (cheat meal) Sunday brunch of eggs-Benedict. 😀 I think by having the occasional animal product, I provide myself with the balance it needs. That is for MY body, MY health, and MY lifestyle based on my health issues and experiences. I don’t apologize for it to my vegan friends. After much experimentation, I have found that is all the animal products I need and thrive on it.

    Once Matt said : I’d rather see 100 people go mostly vegan than 25 people go all the way.

    I agree 110%. I think the environmental impact would be tremendously positive. I also think the impact on animals and humans would also exponentially increase. I’m part of that 100 (mostly because of the support of this site). Thanks to everyone who contributes.

    p.s. also a huge fan of nerd fitness – paleo aside 😉

    • I like what Matt and Jen say very much. That was a fantastic and honest article. In addition I think why do we need to fit in a box. I eat vegan 5 days a week, vegetarian one day and then fish and even a bit if meat on occasion one day a week. People ask me if I am vegan or vegetarian but I can’t really say yes without insulting the purists. So I just say I’m a week day vegan. And like Jen says that is what MY body thrives on and it is better if 100 people would be that way than 25 purists. It’s nice to know I have company in this ‘box’. Thank you very much


      • Interesting approach Gordon. Like it!

        After battling the snowball effect of Vit D deficiency last year, I have taken the less stringent approach and it’s nice to know someone else reading this blog is in the box….. labels, schmabels.

        • Take a multi and get outside. I am vegan and have zero deficiencies. I though know plent of omnivores that do have them.
          I agree though with not being stringent. It has to be desire. Elimination type diets are usually more dangerous than helpful. It’s best when one wants to include certain types of food than just attempting to go without others.

      • I am vegan for both ethical and health reasons and I would LOVE if my family (all of whom have health issues and whose idea of vegetables is a spoonful of frozen, tasteless corn or a white potato) were weekday vegans. The planet and it’s inhabitants would be healthier if more people ate as you both do! And for some who do so and continue to learn more, they may be more inclined toward going all the way if it feels right for them once they experience the benefits and learn that it is doable.

        I appreciate anyone looking to make healthier food choices. There is strength in numbers and hopefully we’ll reach a point where fruits and vegetables are subsidized, rather than less healthy foods, and they’ll be more widely available to folks of all walks of life.

        • Mihaela says:

          I was vegetarian for 5 years and vegan for a year. In january this year i found out that my vit D and my B12 were very very low….vit D for example was 4. I started eating salmon and sardines. Hope i will get better because supplimenting isn’t something natural and i believe that nature knows what is best for us. So, i’m glad that i hear that you are eating little animal products also. Life is about equilibrium and not extrem things. Thank you!

          • Hey guy, just to let you know; the sun is the best source of Vitamin D no animal or plant will replace that. Also read the article that Karen provided here’s the link

            You can choose to eat if you like, but know it is just as much a supplement as the actual supplements since meat does not make B12, bacteria make it. Bacteria that you and I have in our small intestine and colon. You deficiency may also be linked to intestinal problems, as most B12 problems are, they are never because of lack of eating meat. That is a meat eating myth.

            I hope you get better as well.

          • Christian says:

            I just go in the sun for vitamin D. Half an hour and your body makes all it needs for the day, plus it feels great haha

  7. I didn’t think I’d inspire your next post, but thank you for the information. It is a well-written article and makes logical sense. I’m even somewhat on board with you concerning the grains. However, I believe that the basic grains of today have been modified/hybridized so much from the ancient grains like Einkorn and Emmer that it’s not accurate to compare eating grains 100,000 years ago to the grains that are used today. Thus, I avoid grains.

    • If your only argument for not eating something is that they are different from the most ancient form, then you wouldn’t eat vegetables or chicken either, both of which have been dignificantly modified. This singular notion of only eating what we think our ancesters ate is quite frankly not a very useful lense. I prefer to rely on peer reviewed quantifiable and observeable studies to make my food choices. So I eat whole grains.

      • We’ll have to agree to disagree. There is certainly a lot of quantifiable evidence that our bodies were not meant to process whole grains, gluten-based grains in particular.

        • Eliot W. Collins says:

          Apparently my body has evolved; I never have had any problem with whole grains.

          On the other hand, I do avoid many wheat products, e.g., bread and pasta, not because they contain gluten, but rather because they are essentially empty calories with limited nutritional value.

          I do enjoy oatmeal, even if it was “Manufactured In A Facility That Processes Wheat”.

        • nunyabeezwax says:

          the ONLY problem with gluten is if it’s not broken into it’s amino acids and passes on into the intestines as a undigested protein. The cause of this is typically weak stomach acid. It’s the person not the protein. Drinking alkaline water (all tap water , bottled most mineral water) soda pop , beer or taking “antacids” or drinking baking soda etc. can cause this. The only other problem with wheat is that it like all seeds/nuts/beans needs to be soaked and or sprouted to remove enzyme inhibitors, anti nutrients. No flour on the market comes from sprouted grains. The real problems with wheat made into flour is the addition of bromides, and aluminum which cause sever endocrine system dysfunction. This is the real culprit in the wheat bad for you scenario. This gluten free fad crap is nothing more than a smoke screen to cover up the truth you just learned . Improper growing, improper preparation, compromised digestive system and toxic additives are the valid topics not- Wheat it’s self

          • Hello, it was very interesting reading your comment and I was wondering if you could provide me with the sources for this. I am very interested and I thank you in advance.

        • Actually, most against whole grains are fine with gluten. They claim gluten has gotten a bad rap. There’s no need to avoid gluten, other than desire, unless one has Celiac’s disease. People can be allergic to almost anything. If one is allergic to strawberries it doesn’t mean all others should also avoid strawberries. The biggest issue is over consumption. People tend to load up on a few certain things. Eat a variety of foods and there shouldn’t be a problem except for any allergies.
          BTW, the whole grain issue is often about the lingnans. Some plants don’t agree with humans unless prepared certain ways. It isn’t advisable to consume 100% raw almonds. Some do but only a few a day. Plants don’t have the claws and teeth animals do so they had to develop something as a means of protection. The meat eaters don’t not eat it because it could protect itself prior to being prepared. The same goes then for the plants.

  8. Hello!
    I have read that B12 used to be in the soil, as you mention, and that even animals that we eat do not naturally have B12 in their bodies- they eat it through the grasses and then we eat it through the animals bodies. However, since animals are starting to be grain-fed, B12 deficiency is becoming a global issue for vegan’s and meat eaters alike!
    I agree our diet can evolve and since we are now able to supplement, this is a viable option.
    An interesting resource :

  9. paul hughes says:

    It is true that B12 is not found in almost all plants but it is found ON plants. Because of pesticides and the over washing of produce we end up with B12 deficient foods. Because of this approx 40 per cent of meat eaters are actually deficient in this vitamin. However, recent studies have shown that vegans actually produce more B12 inside their own bodies than people who eat meat. The reasons are not definite for this but it appears that by ingesting B12 from meat it actually suppresses our own system of production. It is possible to produce enough B12 ourselves for our own needs. However, to be certain of this then I always recommend my clients to take a supplement or if they do not want to then they should have regular blood work to be certain that their B12 production is sufficient.
    Many years ago (mid 20th century) we did not have the same problems with pesticides and our food tended to be grown organically as a matter of course. Consequently the vegetables we ate had a much higher level of B12 on it.

    • Regarding vegans producing more B12, that’s very interesting. I hadn’t heard that before. Do you recall the source? I’d like to look into it further. I’ll still supplement to be safe, but I’d love to learn more. Thanks!

      • nunyabeezwax says:

        your issues could be solved by including mushrooms in the the diet which contain both b12 and vitamin d. buy your mushrooms and set them in the sun for a vit. d boost

      • nunyabeezwax says:

        dont know why my mushroom post ended up here but this was what I was going to say about your post: The reason there would be a higher amount of b 12 being made is likley because of the high quantity of fiber and undigestable starch/ sugars which were formally thought to be of no real use except maybe sweeping your guts clean but it is now known that fiber and resistant starch is what feeds the good bacteria in your body and in turn they produce alot of good stuff essential to your health. Not enough fiber and starch equals nutrient malabsorbtion and leaky gut. You can get “bad “bacteria overgrowth like candida that when starved goes looking for food and transforms into a fungus with hyphae or little roots that poke holes into the intestines causing leaky gut and all that comes with it. This is one of my key talking points when arguing against no carb diets. You cut the starch out you will become ill. Health is found in the guts. Cheers

    • Excuse my ignorance,but is the B-12 you get from vegetables the same as the B-12 produced from eating meat?

  10. The healthy human liver stores enough vitamin B12 to last almost six years before deficiency becomes an issue. It is true that the human gut flora produces Vitamin B12, it does so well after the Ileum where it is absorbed. We must intake sufficient B12 at least every few years to replenish the liver’s stores. B12 deficiency is most common in vegan cultures such as those found in areas of India. Supplementation is necessary in a vegan diet.

  11. Hi, for those that may not know B12 is a bacteria found in soil, animals get it from eating the roots/soil of plants or it is supplemented in their feed, it is not inheriently found in them – we would get it too if we ate roots/soil but we wash and disinfect our produce plus our commercial agricultural soil is so depleted of minerals and nutrients we need to supplement, and not just vegans – many people are found to be low.

    • And it is only found in soils that contain cobalt (why “cobalamin” is in its name), and soils are becoming deficient in that mineral (especially soils subjected to non-organic methods of production).

  12. Thank you for the great post. It was informative and well written!

  13. Kevin Calderon says:

    I think you should all look into the 80 10 10 book by Douglas Graham. No need for b12 supplements or animal products in order to maintain a healthy lifestyle. Ultra-marathoners and iron man athletes have thrived on his methods of a raw vegan diet for countless years now. T. Colin Campbell from the china study lines up with his views in his new book whole as well.

    • But, I am vegan and am B12 deficient (confirmed by a blood test at my doctor’s). So… I DO need B12 supplements. Right?

      • Yes, you do. Try lozenges or liquids. If it’s a gut issue rather than the foods you’re eating then your body may not properly absorb the pills.
        I am vegan and nevr have I been B12 deficient. I though know a few meat eaters who have been. One was in her 20s and had to giver herself shots.

  14. I agree that anyone can have a B12 deficiency, even if they include meat products in their diet. Just like people who do not eat animal protein can still have high cholesterol, etc. Some things are hereditary and out of our control, so we should all have our vitamin levels checked, not just those of us on a more selective diet.

    I don’t think everyone is “meant” to be on the same diet. What works for me is not necessarily going to work for the person next to me. It’s easy for me to say I don’t eat meat because I really, truly didn’t miss it when I cut it out. But for some of my friends, they go crazy without it.

    I do believe in knowing about and researching WHAT you are eating: where it comes from, what chemicals are being used, how the animals were treated, etc. Being educated is one thing, but turning a blind eye is another. There are a lot of people fighting for us to have the right to know what is in our food, and we shouldn’t make those wasted efforts. If we care enough, the information will eventually become more accessible, and “cleaner” food will continue to be readily available and more affordable.

    We can’t convert everyone we meet, but we can lead by example. I am feeling a slight victory in that one of my most carnivorous friends has taken to hunting his own meat or buying from local butchers, planting gardens so he can eat his own clean produce, and making an overall effort to healthy, clean eating. We finally have some common ground and I’m proud of him. 🙂

    • Agreed that the ‘best’ diet can often be the local one. I saw a study, years ago, that an American man ate terribly yet had no real health issues but a Mediterranean man who immigrated into the America ate the same terrible American diet and developed diabetes, cholesterol issues, etc. It can be what one is used to and their genes, their parents’ diet.
      Making healthy choices though no matter where you live shouldn’t hurt.

  15. I get plenty of B12 from spirulina. It also provides lots of iron, beta carotene, amino acids and EFAs. The amount of B12 in spirulina gives me tons of energy and is adequate enough that there is no need to supplement.

  16. Good stuff Matt! And Karen’s follow up was very informative and good points. I think it is important that everyone realizes that each body is different. Some people may have a certain deficiency regardless of the diet they follow. You really need to establish a baseline for yourself to fully understand what elements you are naturally missing and try to replenish those through diet or supplementation. I have been following a rigorous endurance training schedule while maintaining a vegetarian diet for the last 2.5 years, and vegan for the last 6 months. I have never felt that anything was missing or my energy levels low, except for periods where my sleep has been off.

    I believe its most important that people adapt whatever diet works for them. I would rather see someone adopt a partial vegan/veggie/plant-based/whole-food diet and stick with it then going to the extreme, not having it work and resort back to a heavy animal-based diet.

  17. Real B12 deficiency is not pretty. I remember a teacher of mine years ago who followed a macrobiotic diet and eventually developed nerve damage and had difficulty walking. There are so many important body functions that are dependent on good B12, B6 and folate intakes. Vegans and those who eat a lot of plants get enough B6 and folate. It’s so easy to take a B12 supplement or B12 fortified foods and you can’t OD on it. Many who follow all kinds of diets are B12 deficient.

    • Well said, Karen.

    • This post is so old, but I came here because I took a b12 supplement and my face broke out that night from it, the weirdest tiny bumps all around my mouth and forehead. Is that considered overdosing? I don’t want to supplement now because of that, I have enough acne issues. It was a sublingual 1000 mug that I was going to take twice a week. Should I instead have a smaller amount every day? Why am I so confused lol!

  18. Great post Matt. I feel that many of us are on the path to healthier eating, which to me is different for each of us. Who is to say which one is better? We need to figure it out for ourselves. I do know that my journey has taken me to choosing a plant only diet because it has made me feel the best. I know that I do not have a B12 deficiency, but take a supplement several times a week. It is great to have a forum like this to help us make informed decisions.

  19. Another terrific post. I follow Dr Furhmsn’s neat vegan diet and I have never felt healthier or stronger. I hope to move to a completely vegan diet but I still occasionally eat fish. I do supplement with B12

  20. There is one thing I know and that is as a meat eater I needed B12 shots; as a vegan I don’t.

    • This is fascinating to me because I am vegan and must give myself B12 shots. My doctor told me I would have to do this forever and would never be able to switch to supplements because of “how deficient I had been”. But, once the levels are up again (as mine are now – they are fine), why can’t I switch to supplements? I’m thinking of switching doctors instead! So I’m interested to hear that you used to need shots and now don’t… I may have to press her more on this issue or perhaps get a 2nd opinion. I’d love to get off the shots.

    • You may now have a healthier gut.

  21. The more and more I learn about these things, the more its seems that the commonalities are much more important than the differences (from health perspective).

    You have two groups, one that eats no meat (and thus eats a lot of plants) and another group that east a lot of plants + some meat. We often focus on the differences: one group eats meat and the other doesn’t. But the evidence seems to suggest that the similarities are much more important: both groups eat lots of plants, and so both are pretty healthy, all else equal. The takeaway is that eating a whole food based diets that is mostly plants is very healthy, especially when compared with the SAD,

  22. Bill Jennings says:

    Heather “Anish” Anderson and Josh Garrett both vegan broke the existing record for hiking the Pacific Crest Trail by 4 and 5 days respectively this year. She was unsupported and he was supported. Their diets are a mystery.

  23. Hi
    I just read this post with great interest. I was a total vegan for no less than 20 years when I was diagnosed with cancer last October. At the onset of treatments, I went through a battery of tests including lots of blood tests. Results were bleak; iron deficiency, very low calcium. A nutritionist was appointed and in the course of our several meetings, she urged me to include some fish and eggs in my diet. She drummed in my brain that a vegan diet was not conducive to good health on a longer time span. As per the results, seemed she was right.

    • Eliot W. Collins says:

      Just because one is a veg*n, that does not mean that they have a healthy diet. Many veg*ns love their veg*n junk food. Some even smoke. As long as no animals are harmed, then they do not care. They may even look down on those who follow a veg*n diet exclusively for health reasons.

  24. We are all, whether we are vegan, vegetarian or omnivorous, experiments of one. I’m female, old (over 60) and have been vegan for 11 years. My health isn’t as good as I would like = last marathon 2007 – knee problems since 2008 (torn meniscus) – autoimmune disease (Hashimoto’s thyroididits) 2013. Within those 11 years I’ve bounced back and forth with different kinds of veganism – soy-no soy-grains-no grains fake meat – no fake meat low to no fat – to nuts and avos. Right now I’m mostly raw fruits and veggies, occasional brown rice and beans, spirulina and chlorella supplements (but NOT as a source of B-12) some nuts and seeds. I take a vegan multi (Veganlife) daily with 300 mcg cyanocobalamin and once a week I take a Jarrow 500mcg methylcobalamin. Once a year I get tested – this year’s blood test for B-12 was 790 pg/mL (with the reference being 211-946. I’ve never had B-12 shots. My in-laws were both sad eaters (typical meal pattern- bacon and egg breakfast – ham sandwich for lunch – and a hamburger for dinner) and they both were B-12 deficient in their 70’s and had to supplement.

  25. Love your article, Matt. I’ll just add that if you’re going to try to get B12 from animal foods, check the amounts to see if it’s worth it.
    To get your daily value of B12 from eggs, you’ll need 70 per week! From milk: 2.75 gallons per week! From cheese: 10 pounds per week!
    Source –

  26. One thing to add. It is not that meat eater don’t take B12 supplements, they do via the animals because the animals get it in pills as supplement well. Since the animals are not fed on soil reach in B12 anymore (like it was in the past) they get it the same way they get antibiotic and other pills. So it is basically a matter of whether I, as a vegan will take a supplement directly when I am the one to choose which one how much etc or a meat eater who leave it to the industry who grows the meat to decide for them and get it indirectly trough the meat.
    Bottom line- everyone get supplements.

  27. Wendy LaPointe says:

    I agree that bridging the gap between no animal flesh or product and “low” animal flesh or product will do more for our planet’s health overall as well as the health of animals (of all species).

    As for the ethical issues involve, I agree with the PP who basically said we should lead by example. “Be the change that you want to see in the world.” -Gandhi

    With relatively few exceptions, most who are vegan were not always. It serves us well to remember this as we explore the most effective ways to bring about change for animals and our planet.

    • Eliot W. Collins says:

      I would say that world-wide most people who are veg*n were raised that way, and have never had any meat. I could be wrong.

  28. bitchy_vegan says:

    Just about 1 TB of nutritional yeast covers a full day’s RDA of B12. Also, lots of non-vegan food products are fortified (cereal, milks, snack foods, etc), so I see no big deal if I get my B12 from fortified sources, either.

  29. Elsje Massyn says:

    I am not religious – however I am a believer in Creation by a Creator.
    The Bible Book of Genesis 1 verse 29 says that God gave instruction to the first people on earth to only eat plants & fruit along with the animals.

    Proof of very healthy vegan living humans today are evidence that meat is something that came many years after creation. Someone slaughtered an animal – found out they liked the taste of steak and taught their kids generations after generations after that to do the same.

    Read “Essie Honibal’s book: I LIVE ON FRUIT” – that old lady started eating only fruit and veggies after years of sickness and became healed. Her testimony and life was tested in Universities in Cape Town South Africa and her fitness (she was much older than many girls whose fitness was tested against her and she beat them all) – today she is in her 80’s – lives in an old age home here in our town as fit as a fiddle, her mind as bright as it was when she was a young girl.

    The B12 theory I think is meat eating scientists supporting beef farmers business to cause us to believe we need B12.

    There are too many people who followed aunty Essie Honibal’s lifestyle and are living good strong and healthy lives until old age to still believe the B12 theory.

  30. Ive been vegetarian for almost 25 years, and ive had a major B-12 sufficiency for almost 10 years. I take B-12 shots (ie. Cyanocobalamin). They not only give me an exorbitant amount of energy and clarity (it’s obvious when I stop taking the shots), the B-12 helps with the radiculopic pain cause by ny spinal injury 8 years ago.

    There’s not a food out there that my doctor nor nutritionist have found that can supply the amount of B-12 my body needs replenished due to being vegetarian.

    Btw– Technically I shoukd be vegan sibce im allergic to dairy, but I just love ice cream once in awhile! 🙂

    • Ps. I also had a severe Vitamin D deficiency several years ago (blood and hair testing) and had to take 50,000 IUs weekly for three months. Now I take 5,000 IUs at night.

      I buy food fortified with Vit D (Soy milk, Rice milk, etc.).

      I would suggest doing the smart thing and get tested.

      Insomnia ia a sure sign of Vit D deficiency.

  31. I’ve been vegan for over 30 years, I don’t take supplements of any kind and I’m not deficient in anything. I get my B12 from avocados and seaweed. Our bodies don’t need that much of it anyway. But what surprises me that we are still having this argument/debate. There are several plant based sources of B12. I’m living proof it’s possible to go vegan long term! Hell, Einstein was vegan! and he was no dummy 🙂

    • I wish this were true for me! I’ve had blood tests and the doctor found I was seriously B12 deficient (and I eat tons of avocadoes). Now I have to inject it regularly, even supplements aren’t good enough. So – it’s not true for everyone that you can get it from plant-based sources, unfortunately.

    • Interesting article explaining B12 sources for vegans – B12 only matters if it is not analogue and lowers MMA levels. Raw and dried seaweed both raise MMA levels and is not considered a valid option for B12. Avocados have B6, but I don’t think there is any B12.

  32. A Seveth Day Adventist Doctor once told me that as we get older, we don’t absorb B-12 as well as when we were younger. It is best to use a sulingual B12 supplement and place it under the tongue for around 15 minutes daily. Under the tongue is one of the easiest placest to absorb directly into the blood stream.
    Also, if you make homemade seitan into mock meat, adding nutritional yeast is important for the B12 vitamins it contains.

  33. I have been looking for an intelligent, no head in the sand answer for a long time. Thank you so much for this thing on B12

  34. This is a great article. I was eating whole food vegan, and a few months ago I got worried about B-12. I realized how much B-12 clams have, and felt personally (ethically) okay with having a clam once in a while as I’m trying to avoid taking supplements. Now I put just one frozen, cooked clam in my green smoothie every morning. Based on what I’ve read about mercury levels in clams, I concluded that 1 per day wouldn’t be bad. I realize this is an older article, but if anyone is reading this and has an opinion on what I’m doing, please let me know.

  35. Well, I think the difference between causality and correlation is this regard can almost be deemed irrelevant, couldn’t it? If one can conclude that those who chose a plant based diet would also be more likely to make other healthier life choices, well to me, that looks like a correlation. Eating a plant based diet naturally tends to lead people to healthier choices in general, and as a result, live longer than those who don’t. I doubt there is a whole demographic of people who are eating a plant based diet and at the same time are kicking back a 12 pack of budweiser daily. Let’s be serious. Plant based diet = healthier choices. Those two are good friends and they stick together. So its safe to say that plant based diets increase longevity.

  36. I was vegan for 3.5 years and became quite ill because i was b12 deficient. I lost months of my life with some fairly signoficant symptoms. I wish i had known abt. B12 bc it is easy to add as supplement. Clams have very high amount of it and i have been eating those to get my health back.

    i am also eating eggs. I hope to get better soon and drop the foods for ethical reasons. But right now, i just am trying to get back to normal. Thnx for posting this. More vegan websites should talk about this issue.

  37. One thing to keep in mind: ancient or traditional societies that ate mostly plant products no doubt had their foodstuffs contaminated with insects as well as other vermin, so they would consume small amounts of the insects in their food, which might increase their B12. We can’t make our own B12, so it might be a good idea to eat crickets or grasshoppers instead of taking a supplement.

    • We have bacteria in our bodies that produce B12, but we can get sources from supplements if we are deficient. We do not need meats. Ancient societies had more contact with manure and the soil where these organisms dwelled and thus had a higher concentration of these bacteria in their small intestine. They did not require insects or vermin to live.

  38. I wanted to add that plant sources of B12 are not utilized by the body, and that the most common type of B-12 supplement, cyanocobalmin, is not utilized well by those with methylation defects (like MTHFR).

  39. Can’t believe what I’ve just read. This is why I’m stopping following your blog

  40. Michael Hatch says:

    Vitamin B12 nourishes the skin, it removes oil from the skin, it also helps to work against acne, and it helps to pop up the pimples, as vitamin B12 enhances the red blood cells so it also helps to keep the skin healthier. Here is another video you may watch

  41. Gary Transom says:

    Lots of ideas and good interesting articles here, i became a vegan by proxy, my first thought
    of not killing animals was for the animals sake, not for mine, i realised that we have no right to end
    any life really, not from any religious or some following or another of which i do none of it.
    Learning about death at our hands just to get second hand protein with side effects that decays the bodies of those who do this is madness at its best, anyway this b12 lack we have by doing the right
    thing by doing no harm to any living creature is a pain really, how can this be with the way humans have evolved, is it because we have been killing and consuming flesh for so many tens of thousands of years our bodies are now reliant on it. For example: if the whole world stopped killing and ate only that which our bodies are designed to eat given the way our digestive system is made and being herbivores by design could we as a race breed out the need for B12 ? and how many million years would it take to breed out b12 ?
    Something does not add up here with regards to this matter!
    If someone can explain why this doses not add up based on the above. i would be most pleased,
    i have read reams of words on words about b12 and none of it explains why we are like this, what happened to us ? Was our blue print of design altered when no body was watching.
    Why why why, nothing adds up, something is dreadfully wrong.

    • Gary, “it’s so because it’s so”. I read something the other day by a vegan getting very upset that cats play with mice, why they shouldn’t and other such examples of things about the natural world that they didn’t like. Also I’ve seen lots of quite anti-human statements and poltyanna thinking about evolution on vegan forums, which is sad to me. This article and especially the discussion in the comments is one of the best things I’ve seen recently as it addresses reality – we need B12, in this example. Unless we are willing to seek the truth and understand reality, we fool ourselves. I found this page to learn more about B12 especially in the context of a vegan diet and don’t want to stray off topic, but you might as well as ask, why isn’t the moon made of blue vegan cheese?

  42. Thank you for this truly sensible, fact-seeking article.
    Too many “militant vegans” are totally unrealistic and
    NOT helping the cause!
    If, say, 50% of Americans were persuaded to PERMAN-
    ENTLY reduce meat/animal products by 50% (or more),
    MUCH MORE animal suffering could be achieved than if
    only 2% of people were to go totally vegan for several years
    (over 75% of vegans go back to omnivorism).
    EVERYONE–meat eaters and non-meat eaters alike– should
    be united in strengthening our anti-cruelty laws regarding farm
    animals–even if it raises the price of meat and animal products!
    We should also all be united in supporting research into both AFFORD-
    ABLE invitro meat, and research into GOOD, AFFORDABLE meat

  43. Samantha McPhee says:

    I can’t really definitively indicate whether this is true or not but it is something that I have accepted as true. We used to have abundant amounts of B12 in our water supply, through algae before we started chlorinating it. Now I am not proposing that we don’t chlorinate our water in big cities but I do try to filter the chlorine out. For me this answered the question of why can’t I get B12 naturally because nature is smart and I try to avoid anything that doesn’t come from nature. I do however take a B12 supplement because I don’t think I can get the amount of B12 I need through my current water supply or diet. I will however start taking some chlorella after reading this post. Thank you.

  44. zak radzak says:

    Humans can get B12 from plant based foods, Spirulina and some other algeas are naturally rich in B12. The powder has a pungent smell, but little to no taste. I put 1.5 tsp in my morning smoothie. The key is to eat a wide variety of fruits, vegetables legumes and grains each day to stay healthy.

  45. Vegan and need B12? Don’t clean your teeth – or only clean your teeth every 2nd day.

  46. This was extremely helpful~thank you! Love the podcast BTW..

  47. Love the article – makes perfect sense to me!

  48. Chailatte says:

    Wonder if biomes will eventually help get B12 into every body.

  49. I get the urge for something meat like a beef burger or fish this happens every few weeks and I cook myself meat on that day then I’m okay for 2 or 3 weeks eating pure clean plant-based diet been like this since the 90s

  50. One of the best articles I’ve ever read on the subject ..

  51. B 12 vitamin deficiency is very common in athletes. I already take Eligen B12,which is made by emisphere. Eligen B12 is for people with clinically low B12 levels. It is a once-daily oral treatment that normalizes B12 levels without inconvenient injections.

  52. There’s one comment I see often when referring to what we are “all” meant to be/meant to eat.. The easiest thing I think that gets missed is that we’re all 99.99999999999999% the same. Maybe 2-3 more 9’s on the end there, haha. If you sample any other species, it’s pretty simple to identify the diets of those animals. We most definitely ARE “meant” to either eat something or not eat something. It’s not logical to say what works for one of us and not the other, essentially we are all an identical system of organisms that are either meant to or not meant to take energy from certain foods. If you have a genetic disorder, or issue with a certain body function or disease, then in this case medicines are conversation to have aside. Survival is no longer an issue since food is plentiful. We can not make Vitamin C on our own like a strict carnivore and there fore are NOT carnivores(among the other hundreds of proofs I think we can all agree here), that leaves the possibility of being an omnivore. I would agree we are BEHAVIORAL omnivores in the sense that some where along the line AFTER we learned to cook the meat, were we able to eat it. We most definitly can not digest properly big amounts of raw meat and that should be enough to identitfy it’s not “supposed” to be in our diet. With that said, yes we can get energy from consuming meat even though we are not meat eaters by nature…. Now it’s just a preference. So IF you choose to eat meat, it is NOT because your body is so different than another of your identical species, it’s more of a cognitive dissonance situation where one justifies surviving by eating meat simply because they like the taste of it. It’s too obvious, and here is the key to preference, that in our present day society, we are destroying health and environment by consuming meat. Therefore, in my opinion, arguing the benefit of meat is like arguing the benefit of sugar. They’re both directly related to food preference and also diabetes, cardio-vascular disease, liver damage, pancreas malfunctions, etc.. I mean, please show me a person that gets the zuchinni sweats from eating too many…. haha Undoubtedly, if you have seen the movie ” The Great Outdoors” with John Candy, haha, you are familiar with the meat sweats. lol Meat aside, I focus on whole food based recipes, and I stay out of any grocery store aisles with packaged refined processed “food-like” products.. Educate yourself on green-marketing and stay ahead of the brain wash, we’ve since started to call conditioning.. haha

  53. Arletta says:

    (sigh) I have been saying this for years, hoping that someone with more money than I have to do research (like getting certain books) will take it up and look into it:

    1) The Yowli tribe used to be cannibals. They stopped and went to eating ONLY yams. These were jungle grown yams. They thrived on this diet for long enough to know that they didn’t need other foods or supplements. Then, they were forced onto a western diet of canned foods and other ick factors, and, they started developing cancer, diabetes, heart problems, etc.

    2) The Nearings were vegetarians who used some animal products, but, then, they went to being strictly vegan. They were strictly vegan for decades. It is likely, but, not necessarily true, that they did not use manure from animals as they kept no animals and believed pets or work animals were no better than slaves. It is likely, but not necessarily true, that they did not use supplements.

    These two sets of people would probably help set the B12 myth firmly to rest, if someone who had the money to would simply take a good look into the details of their lifestyle.

  54. Great discussion. I have been vegetarian all my 40+ years of life and I keep getting B12/D3 deficiency symptoms every 3-5 years that is followed by a year of attention to supplements and then attention flounders.
    The last episode of D3 and B12 was worse. Maybe because I aging and maybe I am more than before physically active through dancing and hiking. But one simple change this time around has gone a long way. I sit in the sun for 20 minutes a day (that magically took care of most D3 deficiency symptoms within 2-3 days days) and eat a leaf of Aloe Vera everyday. It works wonders (along with shots of supplements) . Just supplements don’t give similar results if I skip on sun and Aloe Vera. Not sure why but something I have tried for last 6 months and results are consistent.

  55. eat SPIRULINA! done

  56. NOT Cyanocobalamin: it is synthetic!!!
    spirulina is chock full of B12 and is natural. And full of everything else you need.
    You could live on spirulina ALONE.
    So, if you are considering a supplement.. now think here… WHERE do you think those companies that aren’t using a synthetic form.. are getting it from?????
    right… spirulina 🙂

  57. But I get B12 from Marmite, which I spread on a cracker of bit of bread. I also get it from nutritional yeast flakes. This is not fortified foods. The B12 is in the yeast.


  1. […] few times a week. Most American diets (vegan or not) lack fermented foods and B vitamins. I take a vegan B supplement daily, and I eat nutritional yeast on everything I make for dinner (salad, stir fry, brown rice pasta, […]

  2. […] I would alter Michael Pollan’s approach to this: Eat a rainbow of whole-foods. Cooked yourself. Mostly vegetables. And, if you’re eating entirely plant-based, take a B12 supplement. […]

  3. […] like what the No Meat Athlete, Matt Frazier says on […]

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