(Why) does some tempeh contain B12?

[Korn]

From http://www.ncbi.nlm.nih.gov:80/entre...t_uids=2380647

"Vitamin B12 contents were determined on 10 commercial tempeh samples purchased from various markets in Jakarta, Indonesia. A relatively high vitamin B12 content was found, i.e., 19 ng/g (ranges from 1.8 to 41.4 ng/g). As soybeans contain no vitamin B12, the amount of vitamin in the tempeh must therefore be derived from the other sources during the fermentation process. The tempeh prepared in the laboratory by inoculation of the commercial starter into the sterile soybean contained a much higher amount of vitamin B12, 127 ng/g (ranges from 122 to 136 ng/g). Pure mold and a single species of bacteria were isolated from the starter and commercial tempehs. Pure mold did not produce vitamin B12 in the sterile broth, soybean and medium used for vitamin B12 production. Only the isolated bacteria, identified as K. pneumoniae, could produce vitamin B12 in those substrates. The presence of mold did not significantly enhance or inhibit the vitamin B12 production by K. pneumoniae. It was, therefore, concluded that K. pneumoniae, the bacteria contaminated during the process of tempeh production, was responsible for the vitamin B12 production."

[Korn]

http://diss-epsilon.slu.se/archive/0...in0-online.pdf

Vitamin production by bacteria during tempeh fermentation

Vitamin B12 is one of the most frequently studied vitamins produced by bacteria. It is normally present in insufficient amounts in vegetarian foods, while it is found in high amounts in animal food sources (Murphy & Allen, 2003). Bacteria such as Klebsiella pneumoniae, Kl. pneumiae spp. ozenae, Kl. terrigena, Kl. planticola and Enterobacter cloacae can produce vitamin B12 during tempeh fermentation (Okada et al., 1985b). Especially Kl. pneumoniae (formerly Aerobacter aerogenes), is considered as being the main species producing vitamin B 12 in soybean tempeh.(Okada et al., 1985b). It is a common organism on plant materials and can grow rapidly at 37°C and pH 5-7, with an optimum temperature for
vitamin B12 production at 35°C (Suparmo, 1989). Growth of Kl. pneumoniae does not interfere with the growth of R. oligosporus (Steinkraus et al., 1983). A mixed culture of R. oligosporus and Kl. pneumoniae has been used to produce a tempeh rich in vitamin B12 (Suparmo, 1989). Citrobacter freundii and Brevibacterium epidermidis can also produce vitamin B12 (Wiesel et al., 1997). Other microbes that can produce vitamin B 12 belong to the genera Propionibacterium, Pseudomonas, Clostridium and Streptomyces (Hachmeister & Fung, 1993). Recently, the probiotic Lactobacillus reuteri has also been shown to produce vitamin B12 (Taranto et al., 2003). Unfortunately, the strain of L. reuteri evaluated by us did not grow well during barley tempeh fermentation (I). LAB can also produce other B-group vitamins (Leroy & de Vuyst, 2004; Sanna et al., 2005). Therefore, introducing LAB to tempeh may enhance the vitamin content of tempeh.

Read a lot more about B12 in tempeh here.

[Korn]

Read a lot more about B12 in tempeh here.

...and, if you haven't read it, here is a short excerpt from that article on PubMed, debunking the myth that only tempeh from Indonesia may contain B12:

It was found that the major source of vitamin
B-12 in commercial tempeh made in Toronto
was a bacterium present as a single predominate
species along with the mold during the fermen-
tation. The Toronto tempeh sample was studied
in greater detail since it contained the highest
amount of vitamin B-12 (63.00 ng/g) among all
the commercial samples assayed (Table 2). The
1974 Indonesian sample contained the lowest
amount (4.00 ng/g). This latter figure correlates
quite closely with the data reported by Stein-
kraus et al. (8), in which a value of 5 ng of
vitamin B-12 per g was obtained from another
Indonesian tempeh
sample.
[...]

The recommended dietary
allowance of vitamin B-12 is 3 mcg/day for adults (Committee
on Dietary Allowances, 1974). When the concen-
tration of B-12 is increased to 50 to 60 ng/g of
tempeh, it becomes feasible for the consumer
to get his or her daily requirement of vitamin
B-12 by consumption of approximately 60 g, or
about 2 ounces, of tempeh.

Remember that B12 in plants, animal products and supplements/fortified foods isn't always 'active' B12.

Tempeh can be made of soy beans, barley, coconut, grains etc., so all we know so far is probably inly that we know very little about B12 in tempeh.

Here's some more info about the various B12 producing bacteria used in tempeh production:

http://diss-epsilon.slu.se/archive/0...in0-online.pdf

Vitamin production by bacteria during tempeh fermentation

Vitamin B12 is one of the most frequently studied vitamins produced by bacteria. It is normally present in insufficient amounts in vegetarian foods, while it is found in high amounts in animal food sources (Murphy & Allen, 2003). Bacteria such as Klebsiella pneumoniae, Kl. pneumiae spp. ozenae, Kl. terrigena, Kl. planticola and Enterobacter cloacae can produce vitamin B12 during tempeh fermentation (Okada et al., 1985b). Especially Kl. pneumoniae (formerly Aerobacter aerogenes), is considered as being the main species producing vitamin B 12 in soybean tempeh (Okada et al., 1985b). It is a common organism on plant materials and can grow rapidly at 37°C and pH 5-7, with an optimum temperature for vitamin B12 production at 35°C (Suparmo, 1989). Growth of Kl. pneumoniae does not interfere with the growth of R. oligosporus (Steinkraus et al., 1983). A mixed culture of R. oligosporus and Kl. pneumoniae has been used to produce a tempeh rich in vitamin B12 (Suparmo, 1989). Citrobacter freundii and Brevibacterium epidermidis can also produce vitamin B12 (Wiesel et al., 1997).
Other microbes that can produce vitamin B 12 belong to the genera
Propionibacterium, Pseudomonas, Clostridium and Streptomyces (Hachmeister & Fung, 1993). Recently, the probiotic Lactobacillus reuteri has also been shown to produce vitamin B12 (Taranto et al., 2003). Unfortunately, the strain of L. reuteri evaluated by us did not grow well during barley tempeh fermentation (I). LAB can also produce other B-group vitamins (Leroy & de Vuyst, 2004; Sanna et al., 2005). Therefore, introducing LAB to tempeh may enhance the vitamin content of
tempeh.

[Korn]

When googling for more info about B12 in tempeh (and the usefulness of the B12 found in some tempeh), I came a cross this link:

http://www.pikiran-rakyat.com/cetak/0303/30/1003.htm

Tempe memiliki kandungan vitamin B12 yang sangat tinggi, antara 3,9-5 ug/100 gr. Selain vitamin B12, tempe juga mengandung vitamin B lainnya, yaitu Niacin dan Riboflavin (vitamin B2).

Based on the language in the article, I suspect that this does not refer to Californian or Canadian tempeh. If any of you understand this language, please translate!

[Korn]

Here's some more info about some of the tempeh variations, for those interested:

Types of tempeh

[chico]

Hi Korn,

How's it going?

I've made acquaitance with a local organic tempeh producer and I'm trying to help him understand why I think he shouldn't promote his tempeh as being a reliable source of vitamin B12.

Are you aware whether the bacteria Klebsiella pneumoniae that is often found in tempeh can produce active B12 vitamin? The studies that I've come accross regarding this subject rely on the old microbiological assays, or chemiluminescence and as such are not reliable methods.
Klebsiella pneumoniae and Citrobacter freundii often accidentally contaminate the fermentation of tempeh in Indonesia, but it seems that some tempeh starter makers, even in the West, also intentionally grow these bacterias to add up to their starters.

http://books.google.com/books?hl=fr&...siella&f=false

I'm looking for some information on this issue to be able to determine whether:
- these bacteria - in the event that they might be present - are capable of synthesizing active forms of corrinoids;
- these bacteria only produce inactive analogs and as such should be avoided in order not to compete with active cobalamins from tablets. ( I expect this to be a polemical, controversial question )

Thanks in advance for your help!

Best wishes

Chico

[Korn]

I've made acquaitance with a local organic tempeh producer and I'm trying to help him understand why I think he shouldn't promote his tempeh as being a reliable source of vitamin B12.

First of all: I had to postpone replyng to this question, and then it got lost in between lots of other things I've had to do. Sorry!

I see your point - B12 analogue thing. There are many myths about B12. eg. that B12 analogues are only found in plants, but B12 analogues seem to exist everywhere, in our bodies, in multivitamins, in B12 fortified food, animal products and so on. A lot of these products are promoted as reliable sources of B12 in spite of the fact that they contain B12 analogues, which isn't good - unless, of course they have been measured and found to a reliable source of B12, and the same is of course true for tempeh.

Are you aware whether the bacteria Klebsiella pneumoniae that is often found in tempeh can produce active B12 vitamin? The studies that I've come accross regarding this subject rely on the old microbiological assays, or chemiluminescence and as such are not reliable methods.

I don't know if you were around when we had a discussion about a similar topic earlier, in a period where some posts never made it to the thread if they contained certain words (!). I have a copy of a post somewhere that never made it to this discussion, and will post it later, but from what I know, both new and old methods to measure B12 can be unreliable, and the same is true for the tests that measures B12 levels in humans (meat eaters and vegans).

B12 found in human blood tests may give a false impression that we have high levels of active/bioavailable B12, while such tests actually shows the analogues as well. I haven't done any studies about any bacteria, so all I know about this is what I've read over the last years.

Klebsiella pneumoniae and Citrobacter freundii often accidentally contaminate the fermentation of tempeh in Indonesia, but it seems that some tempeh starter makers, even in the West, also intentionally grow these bacterias to add up to their starters.

Unlike what some (vegan and other) sites have claimed, the best B12 results in tempeh hasn't come from Indonesia, but from lab tests, so I hope the "reliable B12 in tempeh can only be found Indonesia" myth one day will drop dead. For what I know, we may also have to let go of the idea that B12 in tempeh can be used as a reliable source ever - for a number of reasons.

I assume that you have read the other posts in this thread, and googled the topic thoroughly. The bottom line for me is if B12 found - anywhere - has a positive effect on people that need to increase their B12 levels, and if you have a local organic tempeh produced, why not just test it . or find someone why uses his tempeh and have them tested for B12/MMA and homocysteine?

We are in a in-limbo-ish situation regarding B12, because not only are very few tests made comparing the ratio between bioavailable B12 that has a positive effect on our B12 levels and inactive analogues, but the whole homocysteine discussion is a bit up in the air as well (and has been for years), and those who actually perform the MMA tests aren't exactly claiming that these tests are reliable.

The thing that means something, B12-wise, is if people who need B12 will have their levels increased in a proper way from their B12 sources - be it supplements, food or animal products. Unfortunately, very few tests that rely on real-life results are being made, so I hope you have a chance to use your local tempeh producer's tempeh too see how it affects your (or someone else's) B12 levels.

There are so many more or less 'fanatic' B12 viewpoints out there, like eg. mixing up 'reliable B12 sources' with 'reliable B12 sources we are aware of', where some people claim that no plants ever contain B12 (without having tested more than just a tiny fraction of the plants out there), or that B12 in Indonesia is always reliable, or that all new vegans need B12 supplements, or "meat eaters have good B12 levels due to their intake of animal products" while the truth is that 39% of them have low levels in spite of eating a LOT of animal products and in many cases also supplements and/or fortified food (plus, they are also eating vitamin fortified animals!)


I haven't googled Klebsiella pneumoniae (more than I've done since my last post on the topic) to see what I can find before posting this, but would probably find the same results as you would anyway. But please remember that even if testing B12 in animal 'food' or human blood may be only partially reliable or even unreliable, that doesn't mean that the results necessary won't indicate something useful. The same is true for tests of B12 levels in plant foods. In a lot of studies I've seen, the researchers often conclude with "further studies are needed', just because the results can't be used as reliable info (yet), but these studies are then used as a basis for further research.

Please give your local tempeh a try! Take a blood test, eat his tempeh regularly for some weeks, and take a new test. The results would be a lot more useful than speculations about the B12- effectiveness of his tempeh anyway!

There was a similar test done in UK a few years ago (about spirulina?), but I can't remember having seen any published results. I spoke with one of the guys involved in the study, and he almost seemed to kind of try 'excuse' the findings - by saying that the B12 in spirulina (if that's what it was) didn't come from the spirulina itself, so my feeling was that he was almost disappointed over finding actual B12 in spirulina. Some people seem to have decided that there's no B12 in anything plant like, while others fanatically claim that it's easy to get B12 from plants almost without really having to know what you're doing. I disagree in both these viewpoints!

[chico]

Hi there

As they say better late then never! So first of all, thanks.

So it seems that there is a lot to be said, since you brought up so many issues.

Unfortunately I won't give my body away to science on this issue for a variety or reasons:

- I take sublingual vitamin B12 since a few years already, and I'm not going to stop it to test tempeh;

- There is no reason why the tempeh that I make should have any significant amounts of vitamin B12 analogues (since I'm not making it out of a mixed culture of Rhizopus oligosporus mold and bacteria such as the mentioned Klebsiella pneumoniae)

There are many myths about B12. eg. that B12 analogues are only found in plants, but B12 analogues seem to exist everywhere, in our bodies, in multivitamins, in B12 fortified food, animal products and so on. A lot of these products are promoted as reliable sources of B12 in spite of the fact that they contain B12 analogues, which isn't good - unless, of course they have been measured and found to a reliable source of B12, and the same is of course true for tempeh.

I don't know where you've heard that B12 analogues are only found in plants? I'm curious about that, if you care to elaborate. On the other hand, can you please explain the statement that there is B12 analogues in fortified foods?

How do you want these foods to be measured for B12 content if there is no single measurement technique that can accurately measure active B12, as far as I'm aware (please correct me if I'm wrong)?

Just to make sure, you do use the term B12 analogues as referring to inactive analogues exclusively, right? I wouldn't want us to engage in a discussion based on false semantic premises.

I don't know if you were around when we had a discussion about a similar topic earlier (...)

No, I wasn't around...

Unlike what some (vegan and other) sites have claimed, the best B12 results in tempeh hasn't come from Indonesia, but from lab tests,

Can you please quote your sources?

so I hope the "reliable B12 in tempeh can only be found Indonesia" myth one day will drop dead.

Well the studies made on indonesian tempeh that i'm aware of don't prove there is reliable B12, they only prove there are analogues so I agree with you.

and those who actually perform the MMA tests aren't exactly claiming that these tests are reliable.

I'm not aware of this, some people are claiming that MMA measurement is not a reliable way of detecting a B12 deficiency? Please point me to the right direction, if you may.

There are so many more or less 'fanatic' B12 viewpoints out there, like eg. mixing up 'reliable B12 sources' with 'reliable B12 sources we are aware of',

I'm not exactly sure what you mean by this

that all new vegans need B12 supplements

or this? I hardly see how being on the safe side and making new vegans aware of this would be dismissed as being fanatical?

Some people seem to have decided that there's no B12 in anything plant like

Well I'm not entirely sure who those people are...

[Korn]

please explain the statement that there is B12 analogues in fortified foods?

Check the sticky threads in this forum...

Regarding measuring the effectiveness of B12: we can only use the most reliable methods that are available + of course using B12 in real life situations.

Just to make sure, you do use the term B12 analogues as referring to inactive analogues exclusively, right?

Yes, unless if I specify something else...

Can you please quote your sources?

I tend not to when the sources already are quoted in the same thread. See the earlier posts on this page...

I'm not aware of this, some people are claiming that MMA measurement is not a reliable way of detecting a B12 deficiency? Please point me to the right direction, if you may.

Just click on the word MMA in my post above...

mixing up 'reliable B12 sources' with 'reliable B12 sources we are aware of'

Some people who don't know if there are any plants that can be considered reliable B12 sources claim that there are no plants that can be used as reliable B12 sources, instead of simply acknowledging than there's just an extremely tiny fraction of the existing plants that have been tested for B12/have been tested for inactive vs. bioavailabe B12/have been tested in fresh/organic/non-heated form. Sometimes "we don't know much yet" is the mist accurate statement that can be stated!


To claim that people are 'on the safe side' if they simply 'take supplements' is misleading. There are so many other factors to consider - eg. if they actually have absorption problems/lack intrinsic factor, go vegan when they already have a severe deficiency and need therapeutic amounts of B12/have a history of very high B12 intake/animal products - which in some cases are associated with health problems. And then (again) there's the 'B12 killer' factor.

No vegans have a lower need for B12 supplement than new vegans.

[chico]

Regarding measuring the effectiveness of B12: we can only use the most reliable methods that are available + of course using B12 in real life situations.

Which are? Are you implying that there are any methods out there that are reliable?

Some people who don't know if there are any plants that can be considered reliable B12 sources claim that there are no plants that can be used as reliable B12 sources, instead of simply acknowledging than there's just an extremely tiny fraction of the existing plants that have been tested for B12/have been tested for inactive vs. bioavailabe B12/have been tested in fresh/organic/non-heated form. Sometimes "we don't know much yet" is the mist accurate statement that can be stated!

Ok I'm not going to argue about the way others argue about this issue, that would be a bit pointless. Of course you are right, the only truth is that we don't know much yet, and hence the conclusion "plants are not to be reliable as sources of vitamin B12" for the obvious reasons. I don't see what's fanatical about that.

To claim that people are 'on the safe side' if they simply 'take supplements' is misleading. There are so many other factors to consider - eg. if they actually have absorption problems/lack intrinsic factor, go vegan when they already have a severe deficiency and need therapeutic amounts of B12/have a history of very high B12 intake/animal products (...)

Ok. But "misleading" goes a long way from "fanatical" so I'm not sure of what you're talking about anymore. Of course people can develop a B12 deficiency due to lack of intrinsic factor, as a matter of fact IIRC that's the biggest percentage of the B12-deficient cases, but in that case the fact that these people need to take vitamin B12 is first of all, independant from their dietary regime (ie. being vegan or animal-produce eater) so I don't see the point still.

No vegans have a lower need for B12 supplement than new vegans.

So what? What are you suggesting, let these people go with no obvious sources of vitamin B12 until they develop a deficiency? I really don't understand what your point here is. Please explain in which way new vegans should behave differently than mid-term vegans or old vegans in relation to vitamin B12.

It'll take me some time to read all the links you suggested.
Please just may I ask you this briefly? When you said that there can be B12 analogues in enriched foods is this having to do with the story that iron, copper and vitamin C can transform one analogue into a different kind of molecule? So shall I assume that if these nutrients aren't present the fortified food contains only purely active B12 and no inactive analogues?

[Korn]

the only truth is that we don't know much yet, and hence the conclusion "plants are not to be reliable as sources of vitamin B12" for the obvious reasons.

I think we should move this discussion over to (an)other thread(s), but your statement "plants are not to be reliable as sources of vitamin B12" is not what some people come up with. Maybe a word is missing in that sentence? Anyway - they claim that there are no reliable plant sources of B12, like eg. "The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements."

I don't see what's fanatical about that.

It's not the statement that's "fanatical", it's the fact that some people keep claiming certain things that there's no scientific evidence for over and over again; the activity of keeping myths alive. "Fanatical" is probably the wrong word, but some people spread false info about vegan food/B12 issues so much that they at times seem obsessed with confirming old myths about 'B12 comes from animals", "Unlike meat eaters, vegans need supplements", "All B12 found in plants is false/inactive analogues" and so on.

What are you suggesting, let these people go with no obvious sources of vitamin B12 until they develop a deficiency?

Not at all. I have written about these things for several years on this board, maybe I have explained myself better in other threads?

Please explain in which way new vegans should behave differently than mid-term vegans or old vegans in relation to vitamin B12.

Long version: see other threads. Short version: New vegans are usually recent consumers of animal products. B12 is the only/main nutrient non-vegans normally consume more of than vegans. Therefore, a new vegan has higher B12 levels than a long-term vegan - due to reasons discussed in many of our threads. Therefore (if we use people who don't supplements as the basis for our example here): since they have higher levels of B12 than people who have been vegans for eg. three or 30 years (without supplementation), they are less in need for supplementation than non-supplementing people who have been vegans for a long time. Hence my statement: "No vegans have a lower need for B12 supplement than new vegans." This can also be read as "The longer a person has been vegan (we still talk about vegans who don't supplement here), the more likely it is that he will need B12 supplementation".

When you said that there can be B12 analogues in enriched foods is this having to do with the story that iron, copper and vitamin C can transform one analogue into a different kind of molecule? So shall I assume that if these nutrients aren't present the fortified food contains only purely active B12 and no inactive analogues?

I'm not even close to being in a position to tell you what you shall assume... I just refer to the studies posted earlier in this thread (and elsewhere). I officially have no opinion about this, I try to have no opinions about anything, I just want to look at the facts and and existing research, and I encourage others to do the same! We may come to different conclusions, but that's fine with me.

Let's please continue about tempeh in this thread, and discuss the other stuff - if needed - in threads that already cover these (other) topics!

[chico]

I think we should move this discussion over to (an)other thread(s), but your statement "plants are not to be reliable as sources of vitamin B12" is not what some people come up with.

Well I can't discuss what other people say about this issue. All I can try to discuss with you is what I say and what you say...

They claim that there are no reliable plant sources of B12, like eg. "The only reliable vegan sources of B12 are foods fortified with B12 (including some plant milks, some soy products and some breakfast cereals) and B12 supplements."

Well listen... aren't you nitpicking right now? Logically, if we don't know of any reliable plant sources of vitamin B12, the conclusion is that only fortified foods and pills are the only reliable sources follows and that's just pure logic. I don't see what's wrong with this.

So maybe the most accurate thing to say is that "there are no reliable plant sources of vitamin B12 known to humankind as we speak, I grant you this but I really don't see why you think this detail is so important.

It's not the statement that's "fanatical", it's the fact that some people keep claiming certain things that there's no scientific evidence for over and over again; the activity of keeping myths alive. "Fanatical" is probably the wrong word, but some people spread false info about vegan food/B12 issues so much that they at times seem obsessed with confirming old myths about 'B12 comes from animals", "Unlike meat eaters, vegans need supplements", "All B12 found in plants is false/inactive analogues" and so on.

Vitamin B12 doesn't come either from plants or from animals, it comes from bacteria. You keep on referring to plant sources of vitamin B12 and I believe you to be wrong in doing so.

Myths have to be eradicated, of course, but that goes both ways.

I have written about these things for several years on this board, maybe I have explained myself better in other threads?

Well I'm sorry, I understand that you might be tired to say this over and over again, but you keep on sending me to do background reading on really complicated issues, and I can't do it, so this will lead us nowhere.

Long version: see other threads. Short version: New vegans are usually recent consumers of animal products. B12 is the only/main nutrient non-vegans normally consume more of than vegans. Therefore, a new vegan has higher B12 levels than a long-term vegan - due to reasons discussed in many of our threads. Therefore (if we use people who don't supplements as the basis for our example here): since they have higher levels of B12 than people who have been vegans for eg. three or 30 years (without supplementation), they are less in need for supplementation than non-supplementing people who have been vegans for a long time. Hence my statement: "No vegans have a lower need for B12 supplement than new vegans." This can also be read as "The longer a person has been vegan (we still talk about vegans who don't supplement here), the more likely it is that he will need B12 supplementation".

Fine. But I don't see: what's the point in letting new-vegans take a while before telling them to find good sources of B12? Actually, I have no idea what you say to new vegans, as you didn't tell me as per the previous quote.

I'm not even close to being in a position to tell you what you shall assume... I just refer to the studies posted earlier in this thread (and elsewhere). I officially have no opinion about this, I try to have no opinions about anything, I just want to look at the facts and and existing research

Just look at them and never take any conclusions? I'm lost here. I just wanted to understand your claim that there are inactive analogs in fortified foods. Is this because of vitamin C, iron, copper, etc?
Please tell me something: do you have any reason to believe there are inactive analogs in the soy milk that I drink which consists of soy, water, calcium, vitamin B12 (cyanocobalamin), riboflavin? This product is not enriched with vitamin C or iron or copper.

Let's please continue about tempeh in this thread, and discuss the other stuff - if needed - in threads that already cover these (other) topics!

Well that won't lead us anywhere. You adressed these issues on this topic now you want us to go elsewhere? Where to?

[Korn]

Again: let's discuss Tempeh here, and the other stuff in relevant or new threads. Some very short comments:

Logically, if we don't know of any reliable plant sources of vitamin B12, the conclusion is that only fortified foods and pills are the only reliable sources follows and that's just pure logic.

That's as illogical as saying that there's no Chinese people in Germany if you don't know that there are Chinese people in Germany.

So maybe the most accurate thing to say is that "there are no reliable plant sources of vitamin B12 known to humankind as we speak, I grant you this but I really don't see why you think this detail is so important.

Very little research is done on reliable B12 sources We should IMO just say this and not start talking about 'known to mankind' etc.. This is very important. The way some people inform about B12 creates a false, negative impression about nutrient levels in vegan food (and a false, positive impression about nutrient levels in animal based food).

what's the point in letting new-vegans take a while before telling them to find good sources of B12?

Nobody has ever suggested that...;-)

[chico]

That's as illogical as saying that there's no Chinese people in Germany if you don't know that there are Chinese people in Germany.

Look, this is going around in circles and we're getting nowhere. This is starting to look like an exercise in rethoric.

Very little research is done on reliable B12 sources We should IMO just say this and not start talking about 'known to mankind' etc..

In your opinion? I thought you weren't giving opinions just looking at facts

This is very important. The way some people inform about B12 creates a false, negative impression about nutrient levels in vegan food (and a false, positive impression about nutrient levels in animal based food).

Ok I suppose you could argue that. But by doing so, I think you are undermining one thing.
By saying that there are no reliable sources of B12 apart from, well, er, reliable sources of B12, we are trying to make people aware that the other traditionnally though of as rich sources of B12 aren't reliable. Maybe you would be surprised to know how many people I meet on a regular basis that tell me that tempeh and nutritional non fortified yeast and spirulina and god-knows-what is rich in B12. Maybe you wouldn't.

This is very important. The way some people inform about B12 creates a false, negative impression about nutrient levels in vegan food (and a false, positive impression about nutrient levels in animal based food).

Ok so you have to agree this is your opinion. I think this is in your head. Actually, as I have pointed out before, it's you that give the impression that B12 is to be found in plants or animals, which as you know is wrong. B12 comes from bacteria. Those bacteria happen to be inside some animals and they could happen to be inside / around some plants. So what? Reserach has showed that most people don't get any reliable B12 from no apparent sources, so what's the big deal?

But maybe your real agenda has to do with something else, which is the question: is veganism a natural thing and taking pills a natural thing? And maybe that troubles you. I don't want to speculate so only you can answer that. Looking at the quote in your signature I would definetly tend to believe it has to do with something like that. Anyway, you don't want to discuss this on this thread, fine, as I said, I'm happy to follow you wherever you feel it's appropriate, just give me a sign.

Nobody has ever suggested that...;-)

As I said, I have no idea what you suggested, it's still mysterious to me...

[Korn]

going around in circles

Absolutely. The circle is hereby broken. ;-)

[chico]

Korn, is that all you have to say?

[Korn]

You are right that I 'try to' have as few opinions about possible, because facts are more interesting than opinions. Re. my 'opinion' about your statement re. B12 sources 'known to mankind':

There are apparently several tribes who have been living on a vegan diet for ages time with no supplements (here's one of them), and there's eg. this study concluding that "There were no statistically significant differences between the two groups with respect to any of the examination data, including B12 levels (p < 0.05). Therefore, consumption of nori may keep vegans from suffering B12 deficiency". Claims about what is known to mankind would mean going through a lot of studies and cultures and vegans who haven't taken supplements for a long time and find out what the real facts are. If you haven't done that, we can't discuss what's known to mankind, and such a study would also have to eliminate several factors: B12 test methods that aren't reliable (heating), people who are exposed to 'B12 killers' and so on. The best thing we maybe could come up with is info about B12 sources that are efficient enough to supply people living in our very 'denaturalized' world with B12 - which of course is extremely useful and important info... but this info doesn't say anything about reliable B12 sources for the human race as such (which would include the mentioned people living in the Himalayas, or for people who are exposed to no or very few 'B12 killers').

Regarding where B12 comes from: People list animal products as reliable B12 "sources" all over the world, but of course that may be a wrong way to describe animal products, because B12 originally comes from bacteria, and not from animals. But let's please skip the nitpicking part, otherwise we'll end up discussing where the B12 in bacteria comes from, where does bacteria come from, where does the calcium in cow's milk and folate in plants come from - and end up with discussing the Big Bang and who created God...

My point is that if meat eaters "get B12 from meat", and calcium from leafy green vegetables, calling meat and leafy green plants a nutrient "source" is a very common thing to do. And I'm not saying that people eg. living in the modern Western world can go into a food store and buy a certain plant and be sure that it will provide them with enough B12 with the lifestyle most Western people have. Maybe some can, but relevant studies about B12 in plants are often incomplete, outdated, done on non-fresh food (which seems important), or plants exposed to chlorinated water - or just not happening. One of several reason for this is that Victor Herbert claimed some years ago that there were no B12 in plants except for trace amounts in some rhibozium-
bacteria-containing root nodules, and if you have read some of his texts, he both came up with similar conclusions after having tested only two plants, and also said that this applied to "well-washed" plants. These plants were probably washed in chlorinated water, which is B12-antagonistic.

The labs I have been on touch with all confirm that plants are heated before they are tested, and had no answers to my question about the problem with heating reducing the B12 levels. Since V. Herbert wrote what he did, there have been many reports about B12 in plants - but little reliable info about the active/inactive analogue ration in them, or how the plants were tested, how fresh they were, if they had been organically grown, exposed to chlorinated water and so on. Read more here, and discuss the B12 in plants-topic in that section if you wish.

[chico]

We agree that vitamin B12 can hypothetically be obtained from plants contaminated by vitamin B12 bacteria. So what's the problem? Is it the word "reliable"?

I really don't understand what your stance is.