Twentynine B12 related facts (or "facts"?)

[Korn]

Hi,

below is an excerpt from a long post at another discussion board. The writer is referring to a study by Dr Vetrano and Dr Baker. The source material backing up their conclusions is supposed to be published later this year. As usual, there are discussable "facts" in this article (as it is in almost every article on vitamin B12), but some of the topics on the list below are really interesting.


http://www.vegsource.com/talk/raw/messages/11266.html

1) It's impossible to cause a B12 deficiency in animals (primate especially) , even when they're fed for several years in a purified diet without B12
2) It's possible to lower the level of B12 in chimps and other animals fed in a purified diet without B12 sources when they're injected with ampicillin and other antibiotics
3) Studied vegetarian men have more haemoglobin than meat eaters, and vegan had even more than vegetarian as they had lower values for erythrocyte and higher values for corpuscular volume
4) No serious study in medicine literatures showed that there were B12 deficiency in non-smoker that has been vegan for more than 15 years
5) No serious scientific studies in medicine literature showed that vegan children had lower vitamin B12 (while the wrong misleading conclusions showed this)
6) All the vegan has higher erythrocyte folate concentration and normal vitamin B12 level
7) The non supplementing vegan showed no macrocytosis or microcytosis, no poly-segmented neutrophils and the level was 18,0 g/dl were deficiency is seen only under 85 ng/l
8) The time studied people had been on the vegan diet range from sever years to 35 years.
9) Ten vegan subjects that showed normal or higher level of B12 had been breast fed by vegan mothers.
10) The B12 level of those taking B12 supplements was not much more higher than those that has never taking supplements (321M + 60SE ng/l > 253M + 19SE ng/l)
11) There have been few cases in which B12 deficiency in a vegan caused damage to the nerves and spinal cords and they were showed to be due to gastro-enteritis and other pathological conditions, some meat eater relatives showed the same problem and the same low B12 level
12) Gastric, intestinal, liver organic substances of both primates animals fed for more than three years in a diet without source of vitamin B12 and vegan human had been extracted and showed high content of vitamin B12 and in vitro the extracted organisms showed to manufacture vitamin B12
Both the men and the primate animals had high/normal level of B12
13) Primates animals fed with a purified diet with B12 supplements showed no differences in folate, and B12 level from chimps fed without B12 sources
14) Cow and other mammals don't take B12 form the soil.
Experiments conducts on these animals showed that their B12 level was still high after three years on a purified diet without B12 sources.
Their intestinal compounds showed to contain organisms that in vitro produced B12
15) Both in man and animals not eating vitamin b12 sources micro-organisms able to produce B12 had been isolated
16) Those not taking B12 supplements showed more micro-organism concentration able to produce in their stomachs and intestines than those taking B12 supplement
17) Experiments carried out on vegans showed that B12 manufactured by bacterial flora in the stomach and intestines (not colon) are highly absorbed in the ileum
18) Anaerobic Ci perfringens produced the highest level of B12
19) Anaerobic bacteria in the mouth produce high level of B12 also
20) Cobamides cultures have been isolated from the liver of primates
21) Specker Radioessay is known to be ineffective when need to individuate the TRUE B12 from ANALOGUE USELESS B12
22) All the studies that showed that meat, eggs, milk and cheese are high source of absorbable vitamin B12 have been carried out using Specker Radioessay method
23) Ochromonas malhamensis is the most precise and accurate method to trace B12 in food and individuate the analogue from the human utilisable
24) Laboratory head Dr Fukuoca and H Barker, found that B12 content of meat, liver, eggs, cheese, milk was 99% less than what SP showed and found zero human utilisable B12 in all these foods once they were tested with Ochromonas malhamensis instead of SP.
Ochromonas malhamensis is rarely used because it's not easy to manage and it costs too much, that's why every food composition table of utilisable by man B12 in food is wrong and false
25) Vegetables and many fruits (even when washed) show to contain B12.
Usually plant food have cobamides ATCC 9614 cultures producing this vitamin.
When tested, these food are processed in acid, added cyanide and exposed to heat, doing so all the anaerobic bacteria are destroyed.
That's why we are told that plants food do not contain B12 wile they do contain it.
As G Ruth stated the medium becomes too acid for accurate resulting when testing B12 content of plants food.
26) it's impossible to find B vitamins in isolation.
Where there's vitamin B1, there also vitamin B6 and B12.
All plants containing vitamin B contain B12 as well.
27) The B12 found on vegetables when proper method of finding are used is not analogue, but utilisable by man.
28) Mt. Sinai showed that when a diet is too high in fat and protein the B12 need is triplicated.
29) It was possible to induce vitamin B12 deficiency in primate animals, by raising their fatty acid level over 30%

I know that some of these statements already have been proven (?) wrong, some are being discussed among nutrition experts. Some of the material he brings up is new to me.


From the same site:

Who determines which studies are serious and which are not?

Well, just un example:

1) NON SERIOUS STUDY ( 3 pages)

We have taken 20 vegan, after 6 months 4 of them showed symptoms of B12 deficiency.

2) SERIOUS STUDY (30 pages)

We have taken 20 vegans.
4 of them have been vegan for only 2 years
6 of the have been vegan for 15 years
10 of the have been vegan for more then 20 years
3 of them have consumed some animal product during these years
10 of them habe been breastfed
10 of them have been milk formula fed
4 of the breastfed have been breastfed by vegan mother.
2 of them have been breastfed by a mother that had been vegan for 10 years when she breastfed her children
6 of the vegan in the study smoke 10 sigarettes daily
4 of the vegan gave up smoking
3 of them gave up smoking only 8 months ago
5 of the vegan in the study uses drugs
10 have not used drugs for 6 years
5 of them have sometimes taken aspirin during these years
9 of the vegan take coffe
The diet of the vegan group is ...... ecc...
After 7 months the B12 level, and folate level is (......)
8 of the vegan show a corpuscular level of
9 of them show a iron level of
19 vegan show a heamoglobin level of (.....)
After 28 months their levels are (......)
We tried to give B12 supplements to 10 of them and check the results
After 5 months the B12 level of the ones taking B12 supp. is (.....)
After 5 months the B12 level of the ones not taking B12 supp is (....)
At the end of the study the level of those takign B12 was (.....)
The level of those breastfed was (.....)
The level of those taking coffe was (......)
The level of those smoking (......)
and so on

Here's another thread (from the same message board) about same list. Some of the sources are also listed here.

http://www.vegsource.com/talk/raw/messages/9785.html

A few comments:

1) It's impossible to cause a B12 deficiency in animals (primate especially) , even when they're fed for several years in a purified diet without B12

AFAIK, it IS possible to cause B12 deficiency in animals if they eat plants from soil with low levels of cobalt - I saw a site once discussing how to increase B12 levels in these animals. (Animals are always considered 'reliable' B12 sources, but some of them are getting B12 supplements!)
Also, 'several' years is a bit diffuse - B12 is stored in the liver and other places in the body, and three years without B12 doesn't prove much....

4) No serious study in medicine literatures showed that there were B12 deficiency in non-smoker that has been vegan for more than 15 years

This is actually very interesting, because most B12 studies rarely discuss details about the lifestyle and history of those involved. I still don't think that smoking alone is the cause of B12 deficiency among vegans...

5) No serious scientific studies in medicine literature showed that vegan children had lower vitamin B12 (while the wrong misleading conclusions showed this)

There are studies showing that some vegan children had lower B12, and there are studies that for example show that children that eat Nori daily have the same B12 levels in their blood as non-vegans.

It is true that many studies documenting vegans with B12 deficiency are superficial and and misleading, for example using really old, malnourished or even sick people as example, without explaining that old people often are B12 deficient, without explaining that if people are sick or malnourished, their low B12 status can be a result of their health status, and not necesarrily be the reason for it etc.

'Vegan unfriendly'- doctors (and some vegan friendly doctors too) are often very quick at blaming poor health conditions among vegans on the 'there is no B12 in plants'-myth. This is somewhat understandable, but sometimes wrong, and sometimes very misleading.

6) All the vegan has higher erythrocyte folate concentration and normal vitamin B12 level

.....which vegans? And what is a 'normal' B12 level? Vegans often have low B12 levels, especially compared with the standards definitions based on meat eaters.

9) Ten vegan subjects that showed normal or higher level of B12 had been breast fed by vegan mothers.

The importance of breastfeeding - for some reason - rarely seem to get much attention from vegan nutrition sources. In my opinion lack of breastfeeding (not long enough) is a main reason that some vegan children develop B12 deficiency, because they start life with too little of the natural B12 source nature has provided, mothers milk. Several cases that 'document' B12 deficiency among vegan babies refer to babies that were breatsfed only for 3 or 6 months, and then moved on to soy milk based formula. Unfermented soy contains practically no B12. Some even insist that the use of raw soy can reduce B12 levels....

10) The B12 level of those taking B12 supplements was not much more higher than those that has never taking supplements (321M + 60SE ng/l > 253M + 19SE ng/l)

In cases where B12 levels are around 100 or lower, I think B12 supplements definitely will increase B12 levels in the blood.

Our bodies doesn't seem to want to absorb high B12 amounts from food: the more B12 rich food we eat, the lower percent of the B12 is absorbed. We almost seem to be designed to eat food with lower lelves of B12 in the levens found in animal products.

With supplements this is different, but B12 supplements (just like plants) often contain inactive B12 analogues (as well as some active B12). If the only supplement you take is a multivitmain/multimineral, the copper and iron in the pill can destroy the B12 in it. On day, the vegan movement will be less enthusiastic about the wonderpills.... (But I'm not saying that many vegans need extra B12!)

11) There have been few cases in which B12 deficiency in a vegan caused damage to the nerves and spinal cords and they were showed to be due to gastro-enteritis and other pathological conditions, some meat eater relatives showed the same problem and the same low B12 level

I have also seen this. Again, if a non-vegan (or even a vegan-skeptical) doctor sees a vegan with health problems, they are somtimes too quick in blaming his condition on his diet. Luckily, this is slowly changing...

More later...

[phillip888]

So, I suspect as many people have in the past, that finding the cause of B12 malabsorbtion is far more important than proving that B12 deficiency in vegans is a myth. I suspect smoking causes B12 deficiency because it destroys brain cells and introduces toxins (including heavy metals from tobacco processes in the US) into the bloodstream. Just like alcohol and many other refined drugs. I'd really like to see a study on deficiency myself. I don't find it surprising in any way that B12 is everywhere. It's bacteria... As far as people taking supplements or eating dead animals and having the same B12 levels as lifelong vegans, well I doubt your body keeps all the B12 it absorbs. If it did there might be problems. B12 injections have caused migraines and nausea in patients on many occasions, but they go away after a few days. I've even suffered this myself from taking too many 3000mcg cobalamin pills a week, I assume the body is just flushing excess B vitamins, as it always does.

[Korn]

Welcome back, Philip! I am also very surprised that there are no serious studies on this, which includes all possible factors. I hope The Vegan Society, PETA, PCRM or others have some plans. Or maybe we should take the initative? Didn't you once mention that you had checked how much the needed equipment for measuring B12 costed?

At least, we plan a huge multi-question survey, where we might be able to find out what the long-term vegans who do not take supplements and still have no problems have in common. I suspect that the only way to get further is to accept that there are many details to be taken into consideration. Maybe (take a deep breath) nonsmokers, breastfed for more than 20 months, who do not drink coffee or alcohol, who eat organic food without amalgam in their teeth, avoid too much cooked and microwaved food, and includes a lot of leafy green vegetables, avoid chlorinated water as much as possible and are not exposed to traffic pollution, and have never taken antibiotics and very little fish (mercury!) + have good calcium and vitamin D levels survive well without B12 supplements?

It's time to find out.

[celesta]

I doubt it, Korn. Good lifestyle is protective in general, but if levels of a vital nutrient are chronically depressed, problems will eventually develop. In some people it may take 20 years or more. Low B12 status is more problematic among vegans than vegetarians, and also a problem among omnis who don't eat much meat.

One problem of chronically low B12 status, perhaps not so well publicized but potentially a greater threat, is the associated rise in homocysteine. In the omni, homocysteine is elevated due to inadequate folate intake, but in the veg*n, it's due to inadequate B12 status. Low B12 status is not a joke. See Stephen Walsh's writings at

http://www.beyondveg.com/walsh-s/vit...vegans-1.shtml

A quote:

"Strong evidence has been gathered over the past decade that even slightly elevated homocysteine levels increase risk of heart disease and stroke and pregnancy complications. Homocysteine levels are also affected by other nutrients, most notably folate. General recommendations for increased intakes of folate are aimed at reducing levels of homocysteine and avoiding these risks. Vegan intakes of folate are generally good, particularly if plenty of green vegetables are eaten. However, repeated observations of elevated homocysteine in vegans, and to a lesser extent in other vegetarians, show conclusively that B12 intake needs to be adequate as well to avoid unnecessary risk."

I recently read a quote of Brenda Davis, a respected vegan RD. She is now advising that the current B12 recommended intake is too low and that we should take in more of it. She advises 20 mcg per day from reliable sources. There is some reason to believe that methycobalamin is preferrable to the usual cyanocobalamin because it has many documented therapeutic benefits aside from its usual function.

--------------

The study below illustrates the prevalence of low B12 status among those who do not supplement (for up to ten years):

Ann Nutr Metab. 1982;26(4):209-16.
Serum vitamin B12 and blood cell values in vegetarians.
Dong A, Scott SC.

Serum vitamin B12 and complete blood count values were determined for 83 volunteer subjects from an American vegetarian society conference (USA). Among subjects who did not supplement their diets with vitamin B12 or multiple vitamin tablets, 92% of the vegans (total vegetarians), 64% of the lactovegetarians, 47% of the lacto-ovovegetarians and 20% of the semivegetarians had serum vitamin B12 levels less than 200 pg/ml (normal = 200-900 pg/ml). However, their complete blood count values did not deviate greatly from those found for nonvegetarians, even though some had been vegans or lactovegetarians for over 10 years. Macrocytosis among the vegetarians was minimal; none had mean corpuscular volume greater than 103 fl.

PMID: 6897159 [PubMed - indexed for MEDLINE]


You can find many more (148 other) serious studies at

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed

using this exact search term:

(b12 AND (vegetarian OR vegan))

[globesetter]

Celeste, many of the points you mention in your post have been responded to by the vast amount of information on B12 available on this site. Perhaps you would enjoy reading some of those.


The cause of B12 deficiency has not yet been proven. I find it very interesting to read a wide variety of research, studies, and opinions on the issue. There is much debate, for example, that low serum levels of B12 may not be indicitive of a deficiency. And it is pretty widely accepted that malabsorption may play a much larger role than amount of B12 ingested.


That is not to say, that we don´t need supplements - rather that the B12 issue is quite a bit more complicated than mainstream reports, and it is valuable for us in the long term to understand it thoroughly.

regards,
globesetter

[Korn]

Welcome, Celeste!

if levels of a vital nutrient are chronically depressed, problems will eventually develop.

That's true - we need B12 from the outer world (of course, unless the body is able to recycle B12/produce enough B12 in the mouth or intestines, which still is being debated).

Since there are many inner and outer sources for B12 depression, including even the water we drink that is being used in commercial production of vegetables (which often is chlorinated), B12 IS a problem.

In some people it may take 20 years or more

It is true the the body, primarily the liver, can store B12. What you write represent the a common way of looking at the problem, namely that some vegans survive well without B12 intake, because they ate animal products in the past. But there are many other ways of looking at the problem, even if it of course true that animals - for several reasons - have B12 levels in their bodies that humans and other animals can use. Some animals take B12 supplements too, by the way, if the plants they eat grows on soil poor in cobalt. I have seen examples referring to single examples of people around 80 that are vegans and B12 deficient, used as a proof that "i took ** years for him to develop B12 deficiency". Why do these articles so often ignore that there are millions meat eaters, also chewing multivitamins, that also are strongly B12 deficient at the same age? Let's face that B12 can be a problem, but let's not go to far in saying that 'plants are the problem/meat or supplements is the solution'. This can also lead to serious health trouble. I even think it's wrong to talk about 'plants as such', as they are all different. If it's correct that spinach, mushrooms, barley, alfalfa, some algae and seaweed contain both true B12 and B12 analogues, but enough true B12 that 20% of fall vegans never develop problems, this fact needs more focus. And what about the B12 levels in others plants? And, most important, how much B12 do we a healthy vegan really need?

Low B12 status is more problematic among vegans than vegetarians and also a problem among omnis who don't eat much meat.

It is actually also a problem among omnis who eat a lot of meat, as you can read here: http://veganforum.com/forums/showthread.php?t=240 . So meat, or even just consuming enough B12 obviously isn't a 'reliable' solution. I have many times read that 'plants are not a reliable source of B12, since they contain B12 analogues', but most vegan sites tend to ignore that multivitamins fortified food also contain B12 analogues. And if 39% of people who consume a lot of B12 are in the 'low normal range' and millions of them are deficient (the numbers varies according to which study you read), it's irresponsible to say that animal products or supplements/fortified food is the solution, because there's a huge number of meat eaters who take multivitamins on a regular basis, so the studies on meat eaters include a large number of people who both consume a lot of B12 in their diet AND take supplements. Still many develop deficiency.

One problem of chronically low B12 status, perhaps not so well publicized but potentially a greater threat, is the associated rise in homocysteine.

?We've had many articles on homocysteine here, and it seems that most vegans who check a little around are in the opposite situation: they fear the homocysteine thing and chew B12 pills to feel safe. What many do not consider is that even if too low homocysteine is not good, some people insist that increasing them not necessarily mean that the all the problems associated with low homocysteine will disappear. If 20% of all vegans have a good life without any symptoms of B12 deficiency, this actually proofs the vegan diet alone won't cause problems. I

If you hold a stone in your hand and let go of it, it will fall to the ground. If it falls to the ground in only 80% of the cases, this is a proof that letting go of the stone alone won't make the stone drop to the ground. For some reasons, very few vegans seem to be interested in research on what these 20% have in common.

Another topic people discuss, is how long one can expect to live. Naturally, there is a tendency to think that the longer you live, the better it is, and there are connections between peoples diet and life length. This has to do with homocysteine/heart disease. Some people suggest that since meat eaters have higher homocysteine levels than lacto-vegetarians, this is a sign that eating meat is good. Vegetarians still live longer. Stephen Walsh insist that vegans will live even longer than lacto-vegetarians if their B12/homocysteine levels are good. Others insist that treating a symptom (high homocysteine) won't help much, and ask for proof. People disagree about the 'proof'-part. One reason I started The Vegan Forum is to question and discuss the current, 'established truths' about B12, including statements from some doctors and others that claims a la 'something is wrong with nature, you need pills'. I'm not saying that B12 deficiency is not a problem, and that one should never take supplements.

I'm saying that just to tell people to eat their pills is extremely simplified, and sometimes dangerous, because B12 deficiency symptoms treated with supplements can cover up other problems in the body or in your lifestyle - or even in the environment on this little planet of ours.

In the omni, homocysteine is elevated due to inadequate folate intake, but in the veg*n, it's due to inadequate B12 status.

B6, Folate and B12 influence the homocysteine levels in all people, and folate and B12 levels are influenced by a lot of factors that we tend to ignore. Destroying the natural levels of nutrients in our soil and in water, plus ignoring all the nutrient decreasing factors that exist, is definitely not a joke. Some people look at the diet alone, others on the animals situation, others again on mercury levels, amalgam and pollution. I thing we need to look at all these factors -at the same time, so to speak.

There is some reason to believe that methycobalamin is preferrable to the usual cyanocobalamin because it has many documented therapeutic benefits aside from its usual function.

Methycobalamin vs. Cyancobalamin has been mentioned several times both in our new and old veganforum.com, and the discussion focuses many interesting aspects. If you hang around here, you'll see homocysteine and methycobalamin mentioned a lot .

You can find many more (148 other) serious studies at

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed

using this exact search term:

(b12 AND (vegetarian OR vegan))

We'll soon 'recreate' a thread we had called the 'The B12 research collection'. There are also some interesting books on homocysteine and B12 out there, and Stephen Walsh and Jack Norris also provide some useful info on the net (Walsh also has written an interesting book, with lots of facts, even for people. like me, who look at things from a different perspective than Norris / Walsh).

Plants, as such, are normally be considered 'unreliable sources', and meat, pills or fortified foods are normally consider reliable. I think this reflects only a little part of the story; we need to go much deeper.


You'll find some interesting B12 articles here.

Time for lunch, I'll check my grammar later...

[Korn]

On more thing: most, if not all studies on B12 and vegans I've seen come up with different results, sometimes drastically so. Yes, B12 can be a problem because we don't eat others who ate enough B12, enough cobalt or synthesize/recycle B12 better than most of humans. Let's not start to bang each others head whenever we find a study that support our point of view, but rather, spend our time comparing the facts and try to find patterns. I think I've seen some already - more later.

http://www.ecologos.org/B-12.htm is an interesting site that quotes some B12 PubMed reports that should interest vegans.

[celesta]

Some people suggest that since meat eaters have higher homocysteine levels than lacto-vegetarians, this is a sign that eating meat is good. Vegetarians still live longer. Stephen Walsh insist that vegans will live even longer than lacto-vegetarians if their B12/homocysteine levels are good.

It isn't really an indicator that eating meat is good. It's more an indicator that there is something in meat that our bodies require. We don't have to eat meat to get it. Here's more from Stephen Walsh:

"Many raw food or natural hygiene advocates believe that our evolutionary diet and that of our great ape relatives did not include an external source of B12 and then conclude that humans shouldn’t need such a source. In fact, all the other great apes - even the gorillas - consume insects incidentally along with their normal diet of fruits, shoots, leaves and nuts. Chimpanzees show particular enthusiasm for collecting and eating termites, which have high measured levels of B12. After capture, the blood B12 levels of most primates drops rapidly when they are fed on a hygienically grown and prepared plant-based diet. It is therefore not surprising that humans also need an external source of B12."

Also, many non-human primates are coprophagic.

It's an oversimplification to state that vegetarians live longer than flesh eaters. Occasional fish eaters tend to do as well as vegetarians and both do better than vegans, if the EPIC Oxford study is any indication. But, we don't have all the answers yet. One problem with comparative mortality studies is that there is some crossover between groups. Another problem is that duration of adherence to diet is not always accounted for. A final problem, perhaps the biggest problem, is that the sample size of vegans is really far too small compared to other populations to make any definitive statements yet.

I tend to agree with Walsh in that if B12 status and long chain omega3 status is adequate in the vegan, the vegan should have a considerable edge, but only if his or her diet is high in fruits and vegetables and there are no other deficiencies.

In the meantime, there appears to be no detriment associated with B12 supplementation from reliable sources. However, there is considerable evidence that failure to supplement may result in a hazard to the health in the long term.

There are other substances that might perhaps yield better health in vegans by supplementing, among these are taurine and arginine, some "conditionally" essential amino acids that tend to be in short supply in veg*n diets. The body can synthesize these, but levels tend to be depressed in those who eat only plants. This can lead to problems in platelet aggregation. Mark McCarty has written about these problems in the context of a vegan diet in the Medical Hypothesis journal.

[Korn]

Here's more from Stephen Walsh:

"Many raw food or natural hygiene advocates believe that our evolutionary diet and that of our great ape relatives did not include an external source of B12 and then conclude that humans shouldn't need such a source. In fact, all the other great apes - even the gorillas - consume insects incidentally along with their normal diet of fruits, shoots, leaves and nuts.

This is a very tricky statement. It doesn't say: 'Apes have great B12 levels because they eat insects', but it somewhat makes you believe that that this is the case. It's somewhat in the same league as saying that 'the only way for vegans to get good B12 levels is to eat their faeces or by eating ** bowls of spinach daily'. There are so many reasons that The Vegan Forum doesn't want to participate in this misleading assumptions. One is that that there is very little research on how much B12 a healthy vegan living a natural lifestyle actually need, the research has mainly been done on meat eaters living a unhealthy lifestyle. Another is that if we set up a list of 50 B12 reducing facts, that each reduce your B12 level with 10% (of the total, original value), and you are exposed to only 9 of these 50 B12 reducing factors, your B12 availability/intake/absorption is reduced by 90%. This means, a little simplified, that your levels would have been 10 times higher if you would not have been exposed to your 9 B12 reducing factors. Your low B12 levels are symptoms, and treating symptoms is not enough, even if it might be needed.
A third reason I'm against the mainstream way of looking at the B12 situation, is that an average of maybe 20% (sometimes 5%, as in the example you chose to refer to, sometimes much more than 20%) of all vegans who do not take supplements show good results in blood tests, and a larger numbers have no real life problems. Parts of the vegan movement is on the wrong track, because some leading figures a) seem to be totally un-interested in finding out what the secret is behind the large group of vegans that show OK tests, and the even larger group that get no symptoms of deficiency even with low levels, and b) seem to have very little interesting in trying to document that there are dozens of B12 reducing factors, and that if they were eliminated, maybe the B12 levels originally found in plants and water would be more than sufficient. They tell vegans 'don't get sick, eat your pills, we can't risk hurting the vegan movement by a lot of deficient vegans', and what they achieve is a lot of non-vegans who go 'a diet that you need to take pills to survive on - that's not very convincing'. These same vegans even say that 'the B12 in plants may harm you because of the B12-analogue-thing', and fail to inform that vitamin pills and forified food also contains B12 analogues, and that a mix of true and analogue B12 has proven to treat symptoms of B12 deficiency even when the mix contained 95% B12 analogues. I'm not saying that supplements are not needed, I'm even saying that there are many reasons you could be B12 deficient other than lack of B12 in plants. But we have to go further than assuming that the reason Iranians vegans that didn't develop B12 deficiency was more or less because they are their own faeces.

Chimpanzees show particular enthusiasm for collecting and eating termites, which have high measured levels of B12. After capture, the blood B12 levels of most primates drops rapidly when they are fed on a hygienically grown and prepared plant-based diet. It is therefore not surprising that humans also need an external source of B12."

Yes, that was the example I referred to earlier, and if you look closely, the statement is based on several assumptions.

It's an oversimplification to state that vegetarians live longer than flesh eaters.

That could be, it was a quick comment based on what Stephen Walsh write. I know there are certain things one can eat to achive endurance, get better memory, or maybe even live longer, and personally, I tend to think that if I life ends at 75 instead of 78 because I didn't eat meat, certain herbs found in the mountains of South America or followed other life prolonging theories, so be it. I still would like to know which nutrients and conditions, based on a natural lifestyle, that affects the length of my life. I'll check my Walsh book again and see what his opinion is about vegetarians and life length. But there others than him that suggest that a vegetarian lifestyle will prolong your life.

But, we don't have all the answers yet. One problem with comparative mortality studies is that there is some crossover between groups. Another problem is that duration of adherence to diet is not always accounted for. A final problem, perhaps the biggest problem, is that the sample size of vegans is really far too small compared to other populations to make any definitive statements yet.

A fourth is very similar to measuring bilirubin in 'yellow' new born babies and the risk for brain damage. After a connection between these bilirubin levels and brain damage was discovered, of course one could not start taking risks with babies, and accept very high bilirubin levels in them and see when they got brain damaged. This would have been unethical; it has even been discussed performing such studies in poor countries (where they don't often can't afford to treat the babies with high bilirubin levels anyway) - but since this also would have been considered unethical compared with using the same capacity in treating these babies, there is a lot of missing info, and newborn babies that look yellow are measured for bilirubin, often with blood tests, and treated with light, partly 'to be on the safe side'. What's the parallel to life length/homocysteine? First, it's hard to suggest to a patient that he'll continue with his very low levels just to see when his heart fails or he dies. Secondly, who knows when he would have died if he wasn't treated. The third thing is the one about treating symptoms; 'a hole, the size of a bullet is associated with sudden death', but repairing the T-shirt doesn't help. And there's a lot more...

There are other substances that might perhaps yield better health in vegans by supplementing, among these are taurine and arginine, some "conditionally" essential amino acids that tend to be in short supply in veg*n diets. The body can synthesize these, but levels tend to be depressed in those who eat only plants. This can lead to problems in platelet aggregation. Mark McCarty has written about these problems in the context of a vegan diet in the Medical Hypothesis journal.

This is interesting, and I'm sure there will be more on these issues, and other topics (like methionine) in future threads.