B12 Deficiency Case in Turkey

Another case of vitamin B12 deficiency in a vegan has been reported in the scientific literature. In this case, it was a 44-year old woman from Turkey (1).

She had been vegan for only 9 months (the report didn’t describe her diet prior to that). She developed gradually worsening paresthesia and tingling of both hands and feet for 6 weeks with a B12 level of 135 pg/ml (normal: 200 – 900) and a mean corpuscular volume of 110 fl (normal: 80-96 fl).

Intravenous B12 therapy was started at 1,000 µg/day for 2 weeks and once weekly thereafter. Complete clinical improvement occurred during two months and two months later there was a striking reduction of the MRI abnormalities.

I’m torn about continuing to blog about these cases because it seems almost gratuitous and I don’t want to bring people down.


• It reminds vegan to take their vitamin B12, and each time I publish one of these, some vegans who hadn’t heard this message might hear it for the first time.

• On VeganHealth.org, I tell people to subscribe to my blog or Twitter feed for any changes I make to VeganHealth.org so people know they’re not missing the latest info. (Speaking of which, here is a link to all the non-infant and toddler cases, Individual Cases of Deficiency.)

• I don’t want it to appear like I’m hiding these stories.


• It could be unnecessarily annoying or depressing to read these.

In browsing over the recent years, they only come out about one every six months, so it isn’t that often, though sometimes it seems like it.

If you have a strong opinion about this, I’d be interested in knowing. You can tell me not to post your comment (within the comment – they are moderated).


Gürsoy AE, Kolukısa M, Babacan-Yıldız G, Celebi A. Subacute Combined Degeneration of the Spinal Cord due to Different Etiologies and Improvement of MRI Findings. Case Rep Neurol Med. 2013;2013:159649. doi: 10.1155/2013/159649. Epub 2013 Mar 27. | link

50 Responses to “B12 Deficiency Case in Turkey”

  1. Dan Says:

    Vegan for only 9 months? Surely this can’t be blamed entirely on her plant-based diet.

  2. Jack Norris RD Says:

    The most likely explanation, in my opinion, is that she didn’t eat many animal products in the years before going vegan, so she started out with low B12 stores.

  3. Michael Friesen Says:

    I think the pros outweighs the cons. One of the reasons I come to this blog is that it doesn’t shy away from information that might cast veganism in a less than favourable light. Other vegan authorities seem content to sweep these stories under the rug or else dismiss them as anomalies. If we want a vegan world and not a vegan club (to borrow your expression) then I think we need to face the facts about B12 deficiency, even if they aren’t terribly uplifting. That’s just my opinion.

  4. Daisy Says:

    IMO you should continue to post B12 articles. Denial is high in the vegan world. Virtually every day I see someone assert that vegans don’t need to supplement their diet for anything.

  5. TS Says:

    You should keep posting on these as a reminder to take the B12. People are consistently discovering your blog, and a reminder every once in a while is good. I, for one, sometimes forget to take the nutritional yeast or the multi-vitamin, so it’s also a good kick in the pants for me to make sure I do this.

  6. Anna Says:

    I wouldn’t continue to post them because we don’t need anecdotes to know that vegans (and people over the age of 55) need to supplement with B12.

  7. Nadine Says:

    I’m with Michael, I think providing analysis to go along with these stories is great too as you are actually addressing a serious issue that often gets dismissed by the vegan mainstream. I STILL read and hear other vegans dismissing B12 or supplementation in general.
    Perhaps if you find it a bit tiresome, you could add a notation to your B12 page every time there’s a new case and then mention the update on the blog?

  8. Jack Norris RD Says:


    I don’t find it tiresome, I just want to make sure I’m not irritating my readers. Thanks!

  9. Dan Says:

    @Anna The other commenters have a point. I see a lot of raw food vegans who insist that B12 is not necessary to take as a supplement. This is highly dangerous and people who are going vegan should know about it so they don’t compromise their health (or their kids health).

  10. Caroline Says:

    Thank you for sharing truth! Regardless of how frustrating it can be to learn about those who have had poor health in connection to veganism, it is important to know it happens, nonetheless. Think how great it would be if more journals and media reported how awful the health problems are for people who aren’t vegan… We would certainly appreciate it! Veganism is a serious commitment that requires a bit of research. Your truth sharing will help prevent uninformed vegans.

  11. Jan Says:

    I like to know the good, the bad, and the ugly.

  12. Lori Says:

    Thank you……it reminded me to take my multi (which has B12). Also, I heard that Methylcobalamin is the preferred form of B12 (verses Cyanocobalamin) as it is more absorbable in the body, yes?

  13. Jack Norris RD Says:


    > I heard that Methylcobalamin is the preferred form of B12 (verses Cyanocobalamin) as it is more absorbable in the body, yes?

    I answer that here:


  14. Steve Says:

    You should keep posting. Along with Michael, one of the reasons I subscribe to your blog is that the information always appears balanced … and that’s important to ensure credibility. And don’t be surprised by the number of people who are still ambivalent about taking B12. Good health information helps counter the problem of “I was vegan for a couple of years but went back to meat because of health reasons.”

  15. Joe Says:

    I’d like to still see these kinds of stories, for the reasons you mention!
    I’ve met many vegans who think that they don’t need to supplement with b12 because they eat certain plants or because they think they produce it within their bodies.

  16. Marion Says:

    As others have stated, the level of denial and misinformation amongst vegans remains alarming so posting these incidences is important.
    The raw vegan world in particular is full of unlicensed and unqualified “nutritionists” and “experts” providing very bad advice. It is amazing (and fortunate) that more people are not deficient

  17. Dan Says:

    Hi Jack,

    Please, by all means keep sharing them! I find case reports incredibly valuable – they catch what large trials and cohort studies miss. They allow for a level of detail not contained in population-based reports. They permit the causal phenomena of challenge / de-challenge to take place.

    On a totally unrelated topic, I think you should also note somewhere that folic acid supplementation (which many people are taking) can mask the effects of serious B12 deficiency, by improving the megaloblastic anemia – but the hyperhomocysteinemia and neurologic dysfunction actually gets worse. When the investigating physician does a complete blood count, there may then be no abnormality leading to the need to test for B12 (the dead giveaway would have been the anemia with high MCV, and perhaps megaloblastic cells).

    (As an aside, B12 levels are fairly useless, except in very advanced deficiency. I prefer function testing – i.e. methylmalonic acid and homocysteine testing – when I am suspicious of B12 deficiency.)

    A question. I am currently taking iodine, DHA, vitamin D and B12 with my lacto-vegan diet, but thinking strongly of dropping the DHA and iodine. I know I’ve asked you about this before, but I’d appreciate any general advice you could offer me on that. I consume no fish and had a bad experience with the taste of seaweed.

  18. Jack Norris RD Says:


    I talk about the issues you mention about B12 in Vitamin B12: Are You Getting It? under the sections Measuring:


    My omega-3 recommendations for lacto-vegetarians would be the same as for vegans. If you eat dairy daily, then you might not need to supplement with iodine due to contamination of milk with iodine, but I don’t know how consistently it is found across dairy products.

  19. Maree Says:

    I like reading truth Jack. Please keep posting the facts, I appreciate the relevance, as it helps me to maintain my health as a vegan, and not get caught up in the “magic bullet perfect diet” hype.

    Vegan for (healthy) life!

  20. Dan Says:

    Hi Jack,

    Thanks for getting back to me so quickly. I will re-review your omega-3 recommendations (what I took away from it was that a handful of walnuts containing EPA plus something like 200-300mg of DHA OD would be recommended). With respect to iodine, I don’t drink any milk but I do eat yogurt twice daily (some of which is quite concentrated with respect to protein). Who knows if this will give me enough iodine. I think I am going to try again with different types of seaweed, until I find some that are more palatable.

    I found a vegan source of DHA which provides 200mg per teaspoon (5 mL). The bulk cost is about $36 plus 13% tax for a 200mL supply. Very pricey indeed!

  21. Jack Norris RD Says:


    I’d suggest kelp tablets for iodine. You swallow them whole, so you don’t taste them.

    If money is an issue, then perhaps taking the DHA every third day would be a good compromise, although I don’t know how long it will stay fresh in liquid form. If smell is any indication, Spectrum tablets seem to stay fresh for long periods of time.

  22. Dan Says:

    I do currently consume kelp capsules. My concern is my distate for polypharmacy – I already take one prescription drug and one non-prescription drug (latter is BID dosed – a stool softener); on top of that separate tablets or capsules of kelp iodine, cynacobalamin (B12), vitamin D3 and an omega-3 supplement combining 600 mg of EPA with 300 mg of DHA (which I am thinking of replacing with the vegan DHA-only supplement, after reading several times all that you have written on omega-3’s, including the ability to get EPA from diet). So, total daily pill burden = 7 tablets or capsules.

    I will probably be able to find some palatable seaweed locally in an Asian grocery store (though it’s far cheaper to consume supplements). I don’t need the EPA as I consume a lot of nuts (although I realize now I am also consuming far too much LA in the form of crushed sesame paste – i.e. tahini – on salads every day). On days when I can get enough sunlight on unexposed skin, I can drop the vitamin D3. So, things are not so bad!

  23. Jack Norris RD Says:


    I also have a strong distaste for most seaweeds, but I find nori sheets, used in sushi, to be palatable (and even like them). If you haven’t tried those, you might.

    I wouldn’t worry about the tahini paste – I doubt it can significantly reduce your omega-3 conversion. I certainly don’t worry about it for myself. It’s large amounts of straight oils high in omega-6s that I think should be minimized.

  24. Carrie Poppy Says:

    I definitely vote for continuing to share them. The nature of anecdotes is a double-edged sword, I think. On the one hand, posting too many can seem overkill or like the problem is bigger than it is, as you mention. On the other, once you start to share them individually (instead of stats like, __% of vegans develop B12 deficiency, which afaik is data we don’t have), if you ignore some, you might make the problem look far smaller than it is. My fear, in the long run, is that as my generation of vegans gets older (I’m 29), a huge swath of us will get symptoms of B12 deficiency in a decade or two, and it will get noticed in the media as a huge problem. I would rather blogs like yours, which right now are (mostly) speaking to existing or potential vegans who already care about this issue, point out a potential problem, than have this be something the whole world points to and says “ah ha! A great reason not to go vegan.”

    Keep em coming!

  25. Dan Says:

    Jack, thanks for all the help and advice. I will definitely get some nori sheets.

    When I looked up tahini some time back (http://nutritiondata.self.com/facts/nut-and-seed-products/3142/2), I found that one tablespoon contained 3469 mg of 18:2 undifferentiated polyunsaturated fatty acids (which I believe is the same thing as LA, or at least a rough surrogate of LA). I would say I eat about 3 tablespoons diluted with lemon juice on salad every day – so, if the above is accurate, that is 10.5 g of LA just from tahini alone (not counting from all other sources of LA in the diet – though dinner is cooked usually with {extra virgin} olive oil, which is very low in LA).

    According to a randomized trial I recently came across in BMJ, substitution of dietary saturated fat with an LA-containing margarine actually increased rates of coronary, cardiovascular, and all cause, mortality. This was consistent with other trials in the meta-analysis performed by the same authors as a supplement to the authors.

    Speaking of all this, it may be that my own nutritional self-experiment could be of interest to one of your many readers. I definitely had metabolic syndrome – I had 4 of the 5 NCEP criteria plus an elevated hsCRP and family history of all the same. I went on an Atkins-type diet and lost about 30 lbs and had some of the best serum chemistry in my life (with reductions in blood pressure, waistline, hsCRP, triglycerides and amazing improvement in HDL). However, my total and LDL cholesterols went through the roof! Several colleagues of mine, who were cardiologists, and not familiar with my diet, taking a glance at my lipid profile thought I had familial hypercholesterolemia (FH) – until I mentioned that the baseline (pre-Atkins) cholesterols were elevated but not nearly as bad (I believe I am a hyper-absorber of dietary cholesterol). Now I am adhering very well to a carb-restricted lacto-vegan diet, and a further 15 lbs have been lost. However, I find it is necessary to supplement with micronutrients that are missing from this diet, as noted above.

  26. Ricki Says:

    I agree that she likely was low to begin with. Still, I think it’s important to share these stories so people will know. I once had a chat with a now-prominent vegan cookbook author and authority, who, after 2 years being vegan, had NO IDEA she was supposed to take Vitamin B12 supplements! If only once person learns from this, I think it’s worth posting.

  27. Stephen Says:


    I join other readers in supporting rigorous B12 deficiency reporting which I never find boring.

    The problem vegans have is that genuine deficiency of this multi-pathway singularly complicated vitamin can be fatal yet a credible testing protocol to verify status is still an open issue, unlike Vitamin D and Omega 3 status for which good testing protocols exist.

    Progress is being made. But until a credible B12 testing protocol is established the simple solution is to supplement to be on the safe side.

  28. Jack Norris RD Says:


    > Progress is being made. But until a credible B12 testing protocol is established the simple solution is to supplement to be on the safe side.

    I don’t think there will ever be a testing protocol that will indicate that vegans do not need to reliable source of vitamin B12. Just because you are not deficient at the time of testing doesn’t mean you will be fine with no sources of vitamin B12.

  29. angela Says:

    I would like to know if you also come across reports of non-vegans and B-12 deficiency? Maybe that would help to balance the perception that it’s always or mostly vegans with this issue. I also agree with the other commenters who said this information is valuable and it’s good to get the whole truth, good or bad!

  30. Jack Norris RD Says:


    Yes, there are a great deal of reports of non-vegans having B12 deficiency. But that is a different problem. It is not a problem of a lack of dietary intake but rather of malabsorption or nitrous oxide or B12-metabolism problems. Many plant-based nutritionists try to claim that B12 deficiency does not present a unique challenge for vegan diets, but it does. While the types of deficiency can overlap between vegans and non-vegans, the amount of overlap is very small compared to the number of deficiencies.

  31. Idan Says:

    Not that it matters that much , But Jack, How can you tell she was vegan and not vegetarian ?

    The article only says “Vegetarian”.

  32. Jack Norris RD Says:


    I’ve seen a lot of papers from countries where English is not the first language referring to vegan diets as “vegetarian”. So I just assumed that was the case in this one, too. You could be right, that I don’t know if she was vegan, lacto-, or lacto-ovo.

  33. Dan Says:

    Common problems with B12 malabsorption in both vegans and non-vegans could include intrinsic factor deficiency, exposure to metformin, or exposure to gastric anti-secretory drugs (PPI, H2 blockers). I see alot of B12 deficiency in these settings, and it is pretty much irrespective of oral intake.

    There are also cases of terminal ileum malabsorption syndrome, including subtle cases without any overt disease (overt diseases such as short bowel syndrome, bacterial overgrowth syndrome, Crohn’s disease, etc).

  34. Laurie Says:

    Please keep doing what you are doing. And thank you for doing it! It was through reading your book that I was able to figure out I was B12 deficient (and doing a few other not-very-wise things). My doctor had not been testing my levels despite my age (50) and diet (vegan). Your blog, web site and book have become invaluable resources. So my sincere thanks.

  35. Dan N Says:

    I don’t find it annoying to read and I also think it’s needed until -all- vegans get the message.

    Btw, why do you believe “so many” vegans have a hard time acknowledging the need of B12 supplementation?

  36. Jack Norris RD Says:


    > why do you believe “so many” vegans have a hard time acknowledging the need of B12 supplementation?

    Because it’s easier to believe that a vegan diet naturally provides all the nutrition humans need. The people who promote a vegan diet for health reasons normally do it with the underlying idea that a vegan diet is the most natural diet and that’s why it is the most healthy. B12 throws a wrench into those theories.

    A lot of people want to believe they live natural lives. Here are more of my thoughts on this:


  37. Anna Says:

    It’s a good idea to publish the cases of B12 deficiency. I’m suprised they are so few. B12 deficiency is not that uncommon even among meateaters. Three of my omnivore friends have been supplementing with B12 for years after being diagnosed with B12 deficiency.

  38. Andrea Says:


    I feel your sympathy in this post and I have a question.

    What do you think are the pros and cons of sharing the truth on how humans co-produce B12 with bacteria? ( What I can say though is that it is not produced automatically and this is why everyone who doens’t know the truth needs to supplement. )

  39. Jack Norris RD Says:


    > What do you think are the pros and cons of sharing the truth on how humans co-produce B12 with bacteria?

    I’m not sure I understand what you are asking, but I think you are asking me whether it’s wise to inform people that they have b12-producing bacteria in their colon? I don’t have a problem telling people that, just let them know that for most people in the Western world, that bacteria lives too far down in their intestines to allow the vitamin B12 to be absorbed.

  40. Andrea Says:

    You didn’t understand what I was asking.

    I specifically stated that we don’t produce it automatically. The production in the colon is an automatic production which occurs after fermentation and we obviously can’t absorb it.

    Clearer version: What do you think are the pros and cons of sharing the truth on how humans co-produce large quantities of B12 with bacteria and absorb it?

    All the science on how humans co-produce large quantities of B12 with bacteria and absorb it has been completed but the reason why scientists don’t see it is because the science is scattered across different fields of science, and it takes a genius to connect the dots.

    Now. Can you please answer my question.

  41. Jack Norris RD Says:


    > humans co-produce large quantities of B12 with bacteria and absorb it

    I don’t agree with that. Unless someone has an overgrowth of colonic bacteria into their small intestines (an unhealthy state), there are not bacteria that produce vitamin B12 in humans that can be absorbed.

  42. Andrea Says:

    The irony.

    That is not what I meant and the last part is true with your current knowledge. Hypothetically, lets say that there is a mechanism in which we produce B12 with bacteria and absorb it, again, not an automatic mechanism and no one else but me knows of this mechanism, to my knowledge. What are the pros and cons of sharing this indisputable information?

    I am thinking about the ripple effect this information will have on society and especially my life. Is there enough plant foods available if even half the population decided to stop eating animal products? Am I being paranoid to believe that there will be less plant foods available in stores for me if a lot of people decided to stop eating animal products because it would clearly show that we aren’t omnivores?

  43. Jack Norris RD Says:


    Should what you’re saying be true, I do not think you have anything to worry about regarding plant foods. Since most animals are raised on feed grains, half the population not eating animal products would free up large amounts of land for growing plant foods for humans. Not to mention that, while the problem of vitamin B12 probably contributes to preventing some people from being vegan, it isn’t a factor for most people.

  44. Dan Says:

    There was a very interesting set of correspondence this week in the new england journal of medicine regarding B12 deficiency (http://www.nejm.org/doi/full/10.1056/NEJMc1304350).

    I will quote from it:

    “Oral vitamin B12 at a daily dose of 2000 μg (20 μg absorbed on average) is equivalent to weekly injections of cyanocobalamin at a dose of 1000 μg (150 μg retained).”

    Given the recommendation is to take 50 to 100 micrograms per day in vegans, if the above statement is correct, then this would result in absorption of 1/100th of this amount by the oral route – so, 0.5 to 1 microgram per day. I wonder if this is sufficient with respect to the IOM RDA for vitamin B12, and obviously it assumes that a person does not have pernicious anemia, history of gastrectomy, ileal inflammation, intrinsic factor issues, receptor issues, etc.

  45. Jack Norris RD Says:


    For people with working intrinsic factor, the first 3 to 10 µg of B12 results in about an absorption of 1 to 1.5%. After intrinsic factor is saturated, absorptions via passive diffusion drops to about 1%.

    More info:


  46. Dan Says:

    Jack, thanks for your reply.
    By the way, do you recommend people (especially vegetarians) have follow-up B12 levels to ensure they are properly absorbing the oral supplement dose they are taking? If B12 is in the indeterminate range, homocysteine or methyl malonic acid is often recommended by clinical guidelines, but this would be expensive to get in every indeterminate-range patient.

    There are a few common scenarios I would envisage that would require much higher oral doses than typically recommended, such as people on proton pump inhibitors, H2 receptor blockers (e.g. zantac), or metformin.

    At baseline (pre-treatment), I see alot of people with B12 in the indeterminate range (talking non-vegeterians here, largely) – 200-250 say, and I find it easier to just start a supplement rather than waiting for homocysteine or MMA to come back. I think this is saving the system some money, as B12 levels tend to diminish anyway as we age (slowly albeit, but over decades many elderly will get B12 deficiency).

  47. Linda Says:

    Hi Jack,

    I just found you today and love your web sites.

    I started my transition from SAD to Vegan not quite a year ago, and at this point I would say I am 99% vegan. I’m still learning and your web sites contain a plethora of helpful information and so many things I never even considered or thought about.. I was aware of supplementing with B12, but really hope you continue to post information about it.

    Thank you so much!

  48. Mike Says:

    “I’ve seen a lot of papers from countries where English is not the first language referring to vegan diets as “vegetarian”. So I just assumed that was the case in this one, too. You could be right, that I don’t know if she was vegan, lacto-, or lacto-ovo.”

    The authors distinguish between vegetarianism and veganism earlier in the paper. So in all likelihood, she was a vegetarian, not a vegan.

  49. Jack Norris RD Says:


    Good point. The researchers also said that the B12 deficiency was due to a lack of intake, so one would presume, then, that the patient was eating only a sparse amount of animal products. These researchers are well informed that there are many other reasons for B12 deficiency, so I would assume they ruled out other reasons, but perhaps they didn’t.

  50. Ole Says:

    There are 321 million people in USA. This (http://www.ars.usda.gov/is/pr/2000/000802.htm) study suggests 9% (circa 29 million people, and at least 95% of them are probably not vegans) of them are B12 deficient. For this reason alone, I don’t see why tracing down one single vegan here and there who have had a B12 deficiency make a lot of sense. It would be good to use each of these cases as a reference for discussion about why this person had a deficiency (most likely it was simply a too low B12 intake, but there are other possible factors that should be looked at as well, like how much this person is exposed to B12 reducing factors).
    It would be totally wrong not to emphasise the importance of B12 for vegans (just like it would be totally wrong not to emphasise the importance of fiber, antioxidants, folate and so on for non-vegans. But I strongly disagree with an approach which focuses on every possible risk for people living on a vegan diet, but which not also keeps reminding their readers (most of them are probably non-vegans) that non-vegans have at least as many potential nutrient deficiencies and health problems to take into consideration. A very small amount of vegan sites are so focused on the potential “dangers” of eating vegan but ignore to, on the same pages, remind about the potential risks of living on a standard diet. IMHO this very site is among those sites which give an unbalanced presentation of the the vegan-diet-vs-other-diets risks. This could result in lots of visitors will start to look at being vegan as some kind of disease, or a lifestyle with a high failure risk. And again: In a country with almost 30 million B12 deficient people, documenting that one found one B12 deficient/macrocytic woman in Turkey doesn’t really tell much, if anything – whether she was a vegan or not. I’d rather invest time in an optimistic approach, focus on the benefits og being a vegan and the risks involved in consuming animal products – of course, in parallel with documenting all that needs to be documented in terms of what vegans need to pay attention to, nutrient wise.
    I started eating vegan around 1970, and had periods with doubt or lack of focus and went back to lacto-veg food and even meat in periods. People with a one dimensional, un-balanced, exaggerated focus on the “dangers” of eating plants only were certainly an influencing factor when I started to include animal products in my diet again.

Leave a Reply