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Thread: Do vegans need less B12 than others?

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    Ex-admin Korn's Avatar
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    There are several reasons that the B12 requirements suggested for 'normal people' may not apply to vegans.
    From http://www.vegan-straight-edge.org.uk/b12.htm:

    "Lifestyle risks other than your heavy metal load. Meat or other animal products and refined carbohydrates (sugars) when used generously may more than double B12 needs persons who use drugs (eg Losec), chemicals, or beverages which destroy or remove B12 (e.g., tobacco, alcohol, caffeine, laxatives, etc.) egg albumin and egg yolk decrease B12 absorption
    heavy metals present in food decrease dietary uptake a lack of calcium in food may decrease dietary uptake intestinal disorders or surgery affecting the intestines washing, cooking and light exposure of food containing B12
    [adapted from; Thrash & Thrash, "NUTRITION FOR VEGETARIANS", 1982, "Heavy Metal Bulletin" Vol 2, Iss 3, Dec 1995 and Thorsons "Complete Guide To Vitamins and Minerals"] *B12 detoxifies cyanide in food and also tobacco smoke"

    One more possible reason that vegans might need less B12:

    "the greater quantities of fiber consumed by vegetarians tend to promote the settlement of bacteria in the lower areas of the small intestine and hence also the production of B12 in this region." http://www.veganforum.com/forums/sho...ighlight=fiber

    And another one:

    "The author contends that animal and dairy produce is a poor source of Vitamin B12 since the vitamin is contained in nutrient-deranged foodstuffs which will inevitably destroy the usability of the vitamin. Studies show that those following a typical animal-based diet require more vitamin B12 than those who do not. This is because the typical diet leads to digestive atrophy. Because B12 is peptide-bound in animal products and must be enzymatically cleaved from the peptide bonds to be absorbed, a weakened gastric acid and gastric enzyme secretions (due to a cooked food diet) causes an inability to efficiently extract vitamin B12 from external food. Nevertheless, raw food vegans who have a more powerful digestion actually get more B12 by reabsorption from the bile than they do from external food."

    http://www.living-foods.com/articles/b12issue.html

    And here's something I saw on notmilk.com:

    "In 1996, Victor Herbert determined that B-12 deficiency is rare among vegans, even though most do not take supplemental B-12. His landmark work was published in the American Journal of Clinical Nutrition, vol. 59(suppl), pp. 1213S- 1222S. Herbert wrote: "To a great extent, B-12 is recycled from liver bile in the digestive system...The enterohepatic circulation of vitamin B-12 is very important in vitamin B-12 economy and homeostasis...bodies reabsorb 3-5 mcg of bile vitamin B-12. Because of this, an efficient enterohepatic circulation keeps the adult vegan, who eats very little vitamin B-12, from developing B-12 deficiency disease..."
    Robert Cohen didn't provide any documentation - neither about his claim that most vegans do not take supplemental B12, nor that the enterohepatic circulation actually is all it takes to "keeps the adult vegan from developing B-12 deficiency disease".

    There's also some research performed on animals showing that if thy are fed a high protein diet, they need a lot more B12 in order to survive. If this applies to humans, the vegans who have a lower protein intake than the average meat eater may need less B12 than the average (Western) population, which consists mainly of meat eaters.

  2. #2

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    VITAMIN B-12

    Should You Worry?
    by
    Charles R. Attwood, M.D., F.A.A.P.

    http://www.vegsource.com/attwood/vitB-12.htm

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    Quote Korn
    And here's something I saw on notmilk.com:

    "In 1996, Victor Herbert determined that B-12 deficiency is
    rare among vegans, even though most do not take supplemental
    B-12. His landmark work was published in the American
    Journal of Clinical Nutrition, vol. 59(suppl), pp. 1213S-
    1222S. Herbert wrote:

    "To a great extent, B-12 is recycled from liver bile in the
    digestive system...The enterohepatic circulation of vitamin
    B-12 is very important in vitamin B-12 economy and
    homeostasis...bodies reabsorb 3-5 mcg of bile vitamin B-12.
    Because of this, an efficient enterohepatic circulation
    keeps the adult vegan, who eats very little vitamin B-12,
    from developing B-12 deficiency disease..."
    Robert Cohen aka NotMilk Man, notorious for his crank science (see Vegsource.com for section of articles exposing Mr. Cohen), took Herbert's research out of context. Dr. Herbert did recommend B12 supplements or droping veganism. He clearly stated that a vegan diet not supplemented with B12 leads to disability or/and death. Lots of his research papers and articles can be found here.

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    Ex-admin Korn's Avatar
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    Out of context or not, do you agree that "To a great extent, B-12 is recycled from liver bile in the digestive system..."? Or that "The enterohepatic circulation of vitamin B-12 is very important in vitamin B-12 economy and homeostasis..." Or that "an efficient enterohepatic circulation keeps the adult vegan, who eats very little vitamin B-12, from developing B-12 deficiency disease...". This thread isn't about supplements or not, but whether vegans need less B12 than others....

    You truly seem to believe that vegans need more B12 than others, as you according to yourself take 100 mcg daily, which is 40 times more than the US RDA for 'normal meat-eaters', 100 times more than the WHO RDA and 250 times more than Victor Herbert thought we needed to absorb from food (0.2-0.25 micrograms per day). He even wrote that 'the minimum daily requirement (MDR) for vitamin B12 to sustain normality is probably in the range of of ~0.1 mcg.', and that...:

    'We (the 1980-85 RDA Committee) reduced the RDA for vitamin B12 to 2mcg for adults (which is still more than more than anybody needs) because there was no scientific basis for higher amounts. As delineated above, nobody needs that much, there is no evidence that it has any value whatsoever for humans and, as we discover more and more about the excess of any nutrient, we discover harms we did not know existed. It will probably turn out eventually that too much vitamin B12, like too much of everything, is harmful".
    On the other hand: Dr. Herbert wrote a lot of this stuff around the time, or even before, the relationship between homocysteine and B12 was discovered. Additionally, I can understand that some people don't trust that the B12 in supplements really work, as they are - just like for example plants - known to contain both active B12 and B12 analogues. Let's say that Dr. Herbert, WHO and USA health authorities (and all other national health authorities) all are/were totally wrong and that we need, say 6 mcg pr day, 24 times more than Herberts '0.2-0.25 micrograms per day', and that for example the B12 you eat is rather 'inactive' and contains only 20% true, active B12. That would suggest 24 mcg pr day - but 100? Do you really mean that vegans need more B12 than others? I find it very likely than healthy vegans need a lot less B12 than others. And I support Herbert in that 'it will probably turn out eventually that too much vitamin B12, like too much of everything, is harmful'.

    If we were meant to consume 100 mcg B12 daily, no diet would be healthy enough - even a standard diet normally contains less than 10 mcg daily, often a lot less.

    There's more on use of large amounts of B12 here.
    I will not eat anything that walks, swims, flies, runs, skips, hops or crawls.

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    Ex-admin Korn's Avatar
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    Quote veganmike
    Dr. Herbert did recommend B12 supplements or droping veganism. here.

    Dr Victor Herbert, (which by the way was well known for his lobbyism against alternative medicine) also stated that everyone above 50 should take B12 supplements. He 'warned' against veganism based to his view on the B12 topic, seemed to have little interest in the fact that vegan B12 is available or that organically grown plants contained a lot more B12 than plants grown with chemical fertilizers (which also in some cases contains some B12). He claimed that "Vegan Diets Are Lethal" - but did he ever state that becoming 50 is lethal?

    He claimed that 'there is no vitamin B12 in any vegan diet', which is wrong (look here), and that "[...]our Department of Health and Human Services and our U.S. Department of Agriculture, require that modest amounts of meat and/or fish and/or poultry and/or eggs be eaten daily by everyone." Since we all know that B12 come from bacteria, and not from meat, why didn't he rather 'require' that people on a vegan diet should take supplements? I won't go as far as Atkins (yes, diet-Atkins), who said that Herbert "house[d] an evil spirit that needs to be exorcised" , but I'm not very impressed with his strongly biased attacks on the alternative health movement. Have you seen his book Nutrition Cultism? I would not buy a car from him .
    I will not eat anything that walks, swims, flies, runs, skips, hops or crawls.

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    Ex-admin Korn's Avatar
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    From http://www.diet-and-health.net/Nutrients/vitamins.html :

    "Although, people who have diets high in protein need more B12. A deficiency can cause pernicious anemia."

    From http://www.innvista.com/health/nutri...tamins/b12.htm :

    "What needs to be addressed is the deficiency of this vitamin found in meat eaters. With protein digestion taking up to five days, which causes putrification, harmful bacteria begin to grow crowding out the "friendly" bacteria needed for the formation and absorption of nutrients. B12 and the necessary intrinsic factor are consumed in this type of environment and are never able to reach their intended destination. Therefore, even though the diet may be rich in the nutrient, it cannot be used in the body because of existing factors including this scenario.

    Vitamin B12 is required only in minute amounts, but, when missing, results are not so minute -- producing irreversible brain damage and nervous disorders. The body requires only 3/1,000,000 of a gram per day (or 3 mcg.). One milligram of this vitamin will generally last for a period of two years, with a healthy individual usually carrying around a five year supply. The reabsorption of B12 is stored in the liver and is readily available when the need arises. These stores are sufficient to sustain physiologic needs for several years, even with a total absence of intrinsic factor. It is the only B vitamin that can be stored in the body for any length of time."

    From http://www.textfiles.com/food/b12.txt
    It is known that the B12 is produced in huge amounts in the colon
    (5.0 micrograms/day), though it doesn't seem that it can be
    absorbed through the walls of the colon. The small intestine,
    however, can absorb B12 and indeed some B12 producing bacteria is
    to be found there. It is possible that enough intrinsic factor
    enters the small intestine still sufficiently active to bond with
    B12 for absorption. It is also possible that vegan physiology
    enables a more ready absorption (or lower need?), than
    theoretically expected. Who knows? What we do know that
    people's ability to absorb many nutrients increases as one's need
    for those nutrients increases. For example:

    ". . . vegetarians appear to "undergo physiological
    adaptation enabling them to make somewhat better utilization
    of iron than would be expected from iron bioavailability
    studies involving the feeding of vegetarian diets to
    omnivores or involving the testing of particular components
    characteristic of vegetarian diets with omnivore subjects."
    (from Kies & McEndree "Vegetarianism and the
    bioavailability of iron" in Kies (ed.) NUTRITIONAL
    BIOAVAILABILITY OF IRON, 1982).

    Hence, we must exert some caution in extrapolating the
    nutritional needs and adaptive capacities of omnivores to that of
    vegans. Better, therefore, to look at the DIRECT evidence of
    vegan health or deficiency.
    I will not eat anything that walks, swims, flies, runs, skips, hops or crawls.

  7. #7
    Ex-admin Korn's Avatar
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    Default Re: Do vegans need less B12 than others?

    From http://hills.ccsf.cc.ca.us/~jinouy01...dbacteria.html

    Studies have shown that those eating a typical diet of
    animal products actually require more vitamin B-12 than
    those who do not eat animal products. This is because the
    typical diet leads to digestive atrophy. Because vitamin B-
    12 is peptide bound in animal products and must be
    enzymatically cleaved from the peptide bonds to be absorbed,
    a weakening of all gastric acid and gastric enzyme
    secretions (due to a cooked food diet) causes an inability
    to efficiently extract vitamin B-12 from external food. Raw-
    food vegans, who have more powerful digestion, actually get
    more vitamin B-12 reabsorption from the bile (liver
    secretions into the duodenum) than they do from external
    food.
    (The quote is originally from a book called The Sunfood Diet Success System by David Wolfe).
    I will not eat anything that walks, swims, flies, runs, skips, hops or crawls.

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    Ex-admin Korn's Avatar
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    Default Re: Do vegans need less B12 than others?

    An article in Nutrition Reviews*, suggested some reasons why Indian immigrants in Britain had more B12 deficiency than Indian natives. S.J. Baker** responded in a later article in the same magazine that lack of B12 in the bile (from low B12 stores), or low B12 intake, frees up intrinsic factor in the ileum which then allows it (intrinsic factor) to bind to any B12 produced by bacteria in the small intestine.

    The same Baker*** (and others) measured B12 production of bacteria in the small intestine of people in India using various microbiological assays. They determined that some true B12 was produced by members of the bacteria genera Klebsiella and Pseudomonas.

    Confirmation using chromatography and bioautography showed a molecule with similar properties of cyanocobalamin. Regarding the ability to absorb true B12 when B12 analogues are present, they speculated that since there is some free intrinsic factor in the ileum, it would pick up this B12 (while leaving analogue behind) and could then be used by the body without interference from the B12 analogues produced by intestinal bacteria.


    * Nutrition Reviews "Contribution of the microflora of the small intestine to the vitamin B12 nutriture of man" 1980 Aug;38(8):274-5.

    ** Baker SJ. "Contribution of the microflora of the small intestine to the vitamin B12 nutriture of man" Nutrition Reviews 1981(Mar);39(3):147-8.

    *** Albert MJ, Mathan VI, Baker SJ. "Vitamin B12 synthesis by human small intestinal bacteria" Nature 1980;283(Feb 21):781-2.

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    Default Re: Do vegans need less B12 than others?

    interesting article indianvegan


    i copy from the article:

    Readers of Frances Moore Lappe's Diet For A Small Planet may remember reading in its first edition (1971) that certain fermented soy products, such as tempeh, miso, and seaweed contained vitamin B-12. These sources have recently been shown to contain only the inactive analogue of the vitamin, not metabolized by humans. Ironically, they may actually interfere with the metabolism of active B12.

  10. #10
    Ex-admin Korn's Avatar
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    Default Re: Do vegans need less B12 than others?

    From http://www.vitab12.com/b12.html
    “However, since grazing "meat animals" tend to accumulate heavy metals from the environment, it might be suggested that animal sources of B12 are not as "good" a source as might be supposed. Poultry, especially chickens, are routinely fed fishmeal, which may contain significant amounts of mercury and other heavy metals. Bottom feeding rather than deep sea fish contain the most mercury. Vegans, by avoiding eating higher on the food chain, will therefore accumulate less heavy metals (via diet) and may require far less B12 as a result of that risk factor. We may therefore expect to find a lower incidence of dementia, caused by heavy metal intoxication, amongst amalgam free vegans.”
    Last edited by Korn; Nov 2nd, 2007 at 10:43 AM. Reason: Quote moved over from another thread, because it is more relevant in this thread.

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    Default Re: Do vegans need less B12 than others?

    Quote cedarblue View Post
    interesting article indianvegan


    i copy from the article:

    Readers of Frances Moore Lappe's Diet For A Small Planet may remember reading in its first edition (1971) that certain fermented soy products, such as tempeh, miso, and seaweed contained vitamin B-12. These sources have recently been shown to contain only the inactive analogue of the vitamin, not metabolized by humans. Ironically, they may actually interfere with the metabolism of active B12.
    Note that 'recently' here is written in 1972. Knowledge about inactive B12 analogues have actually existed long before that, and some analogues are known to block B12 absorption, while others are not. The word B12 analogue is also confusing because it is used both about usable, active B12 and inactive, non-usable B12. Some 'analogues' are active, others are not.

    If you look at studies about B12 and it's various analogues, researchers use 'may' and 'possibly' a lot, but when reading articles written by what we could call 'anti-vegans', or vegans that are pessimistic about the nutritional value of vegan food (they aren't many, but they do exist), the words 'may' and 'possibly' are rarely seen. Not only do they use the word 'analogue' in a way that makes readers believe that all analogues are passive and have no value, they also claim that all analogues block B12 absorption. What you quoted, cedarblue, says that 'they may actually interfere with the metabolism of active B12', they don't say that they always do.

    Linguistically, it would be easier if we would reserve the word 'analogues' to always refer to 'inactive analogues'. I know of one site in particular who seem to prefer to use the term 'B12 analogue' in their B12 writings when they write about B12 in plants, which adds extra confusion, especially for people who are used to understand 'B12 analogue' as 'not active, not human available B12'. The end result is that readers who don't have more-than-average knowledge about B12 analogues will interpret what they see as 'this B12 is not active, it's passive, because it's only an analog'. They will assume (even if the writer didn't claim this) that B12 in the described plants is not usable, because... they are confused - or because they didn't notice that the same writer also once or twice use the term 'active B12 analogues'.


    Ironically, they may actually interfere with the metabolism of active B12
    Ironically, this kind of presenting information may interfere with most people's ability to understand the difference between what we know and what we assume, and that a B12 analogue does not need to be 'passive' or block absorption of active B12.

    Anyway: back to topic...


    Phytochemicals are only found in plants. There are hundreds of them, and phytochemicals "Phytochemicals are associated with the prevention and/or treatment of at least four of the leading causes of death in the United States -- cancer, diabetes, cardiovascular disease, and hypertension (7). They are involved in many processes including ones that help prevent cell damage, prevent cancer cell replication, and decrease cholesterol levels."

    One way of looking at disease is a model which suggest that we are 'always' more or less sick, our system is more or less always fighting disease (with anti-oxidants, phytochemicals, vitamins etc). Since plant eaters obviously eats more plants than non-vegans, we also have a higher intake of phytochemicals. In other words, we get a lot more of the stuff that 'help prevent cell damage' and so on.


    Low levels of Vitamin B12 can produce nerve cell damage, anemia, and high homocysteine levels. We have a thread about homocysteine already, and anemia can normally be treated, but permanent cell damage is one of the serious concerns in terms of B12 deficiency.


    As always, there's no reason to ignore the importance of B12, but vegans' increased intake of phytochemicals could play a major role in preventing serious B12 deficiency symptoms to harm people with a high level of phytochemicals in system. When standars have been set for how much B12 humans need, 'most people' are always the reference, not 'people eating a not very common diet that contains more phytochemicals than any other diet'. To me, it seems likely that people on a diet rich in phytochemicals are less likely to suffer from whatever that diet (and the nutrients and other chemicals it is rich in) is known to prevent/treat. Cell damage is on that list, and it's also on the list of possible results of severe B12 deficiency.

    A small excerpt from http://ohioline.osu.edu/hyg-fact/5000/5050.html
    Ohio State University Extension Fact Sheet

    Family and Consumer Sciences

    1787 Neil Avenue, Columbus, Ohio 43210

    Phytochemicals - Vitamins of the Future?

    HYG-5050-98

    Sereana Howard Dresbach
    Amy Rossi
    Recently, you may have heard the words chemoprevention, nutraceuticals, and phytochemicals in the media. What exactly do these terms mean? With the ever-increasing interest in improving our health, it is important to understand these words and understand their function in health care. The information presented here will provide a basis for deciphering the mixed messages that are being delivered in the media, conversations, research, and education.

    Research has demonstrated that cancer is a largely avoidable disease. It is estimated that more than two-thirds of cancer may be prevented through lifestyle modification (1). Nearly one-third of these cancer occurrences can be attributed to diet alone, secondary to our American diet of high-fat, low-fiber content. Fruit and vegetable consumption have been consistently shown to reduce the risk of many cancers (2). A major prevention strategy has been the "5 A Day for Better Health" program sponsored by the National Cancer Institute (NCI), encouraging the public to include more fruits and vegetables in their diet.

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    Ex-admin Korn's Avatar
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    Default Re: Do vegans need less B12 than others?

    Here's a study that could confirm some of the suggestions mentioned in the earlier posts in this thread:

    The nutritional health of New Zealand vegetarian and non-vegetarian Seventh-day Adventists: selected vitamin, mineral and lipid levels.

    Harman SK, Parnell WR.
    Department of Human Nutrition, University of Otago, Dunedin.
    AIM: To determine whether adult non-vegetarian Seventh-day Adventists differ in selected nutrition related health aspects from adult vegetarian Seventh-day Adventists. METHODS: One hundred and forty-one Seventh-day Adventist church members responded to a general health questionnaire. Forty-seven sex and age matched subjects (23 non-vegetarians and 24 vegetarians) were selected for further investigation. Blood lipids, serum vitamin B12, folate, haemoglobin and ferritin levels were measured along with stature, weight and blood pressure. A quantitative 7-day diet record was also completed. RESULTS: Body mass index was similar between the non-vegetarian and vegetarian groups but diastolic blood pressure was higher for non-vegetarian than vegetarian males. Even though the dietary vitamin B12 intake was significantly lower (p < 0.01) in the vegetarian group both vegetarians and non-vegetarians recorded similar serum vitamin B12 levels. The vegetarian and non-vegetarian groups had similar haemoglobin concentrations. While dietary iron intake was higher in the female vegetarian group, though predominantly in the non-haem form, the difference was not significant. Low serum ferritin levels were found in both female dietary groups even though the vegetarian group had a significantly (p < 0.05) higher vitamin C intake. Blood lipid levels were similar in the two diet groups even though the vegetarian group had a lower percentage energy contribution from total and saturated fat (p < 0.01) and consumed significantly less cholesterol. CONCLUSION: Both non-vegetarian and vegetarian Seventh-day Adventists appear likely to enjoy a lower risk of nutrition related chronic degenerative disease than the average New Zealander and have a satisfactory iron and vitamin B12 status.
    PMID: 9577459 [PubMed - indexed for MEDLINE]

  13. #13
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    Default Re: Do vegans need less B12 than others?

    http://www.ncbi.nlm.nih.gov/pubmed/20191257
    Since there's practically no fiber in animal foods, and practically always fiber in plant foods... here's a link to a study from 2010 which concludes that "oat-bran helps to improve constipation management and B12 bioavailability in elderly, with multiple chronic diseases who live in nursing homes". Further studies may reveal if the B12 consumed by vegans generally is more bioavailable than similar amounts of B12 consumed by non-vegans due to a higher intake of fiber.
    I will not eat anything that walks, swims, flies, runs, skips, hops or crawls.

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