Page Summary: Quotes & links for 35+ reports about Vitamin B12 in science journals and by doctors & dietitians. Key points: ~40% of the general population are “flirting” deficiency despite the mass consumption of animals; that most farmed animals are given (90% of) B12 supplements to treat deficiency; that bio-available vegan food sources for B12 include nori (purple lavers), chlorella, certain mushrooms (shiitake, black trumpet & golden chanterelle) & fortified foods; that thanks to increased awareness, fortified foods and supplements the vegans had the best B12 levels in a 2018 study; plus recommendations for choosing supplements.
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Why B12 is important: “Vitamin B12, also called cobalamin, is a water-soluble vitamin that is involved in the metabolism of every cell of the human body: it is a cofactor in DNA synthesis, and in both fatty acid and amino acid metabolism. It is particularly important in the normal functioning of the nervous system via its role in the synthesis of myelin, and in the maturation of developing red blood cells in the bone marrow…
The only organisms to produce vitamin B12 are certain bacteria, and archaea …
[B12] is produced industrially via bacterial fermentation …”
From https://en.wikipedia.org/wiki/Vitamin_B12 (11-Oct-2018)
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From a U.S. Department of Agriculture article titled “B12 Deficiency May Be More Widespread Than Thought” excerpts: “Nearly two-fifths [40%] of the U.S. population may be flirting with marginal vitamin B12 status… the researchers found NO association between plasma B12 levels and meat, poultry, and fish intake … “It’s not because people aren’t eating enough meat,” Tucker said. “The vitamin isn’t getting absorbed”… Fortified cereals are a different story. She says the vitamin is sprayed on during processing and is “more like what we get in supplements.” (emphasis added)
Reference: “AgResearch Magazine” https://agresearchmag.ars.usda.gov/2000/aug/vita
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Dr Jennifer Rooke MD: “IN ORDER TO MAINTAIN MEAT (AS) A SOURCE OF B12 THE MEAT INDUSTRY NOW ADDS IT TO ANIMAL FEED, 90% OF B12 SUPPLEMENTS PRODUCED IN THE WORLD ARE FED TO LIVESTOCK… cattle no longer feed on grass and chickens do not peck in the dirt on factory farms. Even if they did, pesticides often kill B12 producing bacteria and insects in soil. Heavy antibiotic use kills B12 producing bacteria in the guts of farm animals… Even if you only eat grass-fed organic meat you may not be able to absorb the B12 attached to animal protein. It may be more efficient to just skip the animals and get B12 directly from supplements…
The Framingham Offspring study found that 39 percent of the general population may be in the low normal and deficient B12 blood level range, and it was not just vegetarians or older people.
This study showed no difference in the B12 blood levels of younger and older adults. Most interestingly there was no difference between those who ate meat, poultry, or fish and those who did not eat those foods. The people with the highest B12 blood levels were those who were taking B12 supplements and eating B12 fortified cereals…” (capitalised emphasis added)
From Dr Rooke’s article titled “Do carnivores need Vitamin B12 supplements?” at http://baltimorepostexaminer.com/carnivores-need-vitamin-b12-supplements/2013/10/30 Also at this page on her site under the title “Do you need a B12 supplement if you eat meat?” – http://advancedlifestylemedicine.com/?p=1168
Dr. Jennifer Rooke is an Assistant Professor in the Department of Community Health and Preventive Medicine at Morehouse School of Medicine.
Follow this link for more detailed reports about Vitamin B12 supplements being given to farm animals.
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How long does it take to become B12 deficient? The US Institute of Medicine calculates it to “6.3 years.” Source: “Estimation of the Period Covered by Vitamin B12 Stores” at https://www.ncbi.nlm.nih.gov/books/NBK114329/
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A 2018 report in Nutrients science journal found that on average the vegans had the highest plasma concentration of Vitamin B12. Table 2 shows the “Serum Vitamin B12 (pmol/L) Diet Mean ± SD” were:
* Vegan = 292.26 ± 214.52
* Lacto-ovo = 275.32 ± 164.40
* Pesco = 277.59 ± 129.10
* Semi [vegetarian] = 211.06 ± 66.39
* Non-vegetarian [omnivore] = 256.05 ± 136.33
From the discussion section: “Although not all subjects in the current study obtained vitamin B12 from supplements, multiple linear regressions showed that supplements were the strongest predictor of holoTC and serum vitamin B12, independent of other dietary sources of B12, age, gender, race, BMI, and serum creatinine. This supports findings from the Framingham Offspring Study on the importance of vitamin B12 supplements in maintaining normal plasma vitamin B12 concentrations.”
Reference: “Foods and Supplements Associated with Vitamin B12 Biomarkers among Vegetarian and Non-Vegetarian Participants of the Adventist Health Study-2 (AHS-2) Calibration Study”, Nutrients. 2018 Jun; 10(6): 722; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6024521/
Regards the lower figures shown above for omnivores (256.05 for the “non-vegetarian” category and 211.06 for the semi-vegetarians) note that a report in the American Journal of Clinical Nutrition – the “Framingham Offspring Study” – defined 258 pmol/L as “a point at which individuals may be at risk of deficiency”. They found 39% of subjects were below that and there was no significant differences between highest and lowest meat intakes. “Supplement users were significantly less likely” to have low B12 levels.
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“Safest Source of B12” is a 2012 article by Dr Michael Greger M.D. – Excerpts: “What’s the best way to get vitamin B12? Well, B12 is not made by plants; it’s not made by animals either. It’s made by certain bacteria, some of which line the guts of animals, of which people eat and drink. But that’s not the best source, because of the baggage that comes along with it.
Just like we can’t get the iron in beef without the saturated fat, the protein in pork without lard, the calcium in dairy without hormones; we can’t get the B12 in animals without also consuming stuff we don’t want – like cholesterol. For example, to get 47 micrograms of B12 from eggs, because the absorption is so low, we’d have to literally eat hundreds of scrambled eggs a day. 200 to 400 eggs a day! Do you know how much cholesterol that would be? If you got all your B12 from scrambled eggs, you’d consume 69,000 milligrams of cholesterol—practically your entire year’s worth every day…
There has to be a better way!
And thankfully, there is: fortified foods and supplements. Not only the safest, but also the most effective. In the U.S. Framingham Offspring Study, one in six meat-eaters between ages 26 to 83 were B12-deficient. The folks with the highest B12 levels weren’t the ones eating the most animal products, but the ones taking supplements, and eating the most fortified breakfast cereal.”
Reference: https://nutritionfacts.org/video/safest-source-of-b12/ Video Clip is at https://www.youtube.com/watch?v=mA3XjalOkXM
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re: Vegan food sources for Vitamin B12 the ‘Nutrients’ science journal reports: “A survey of naturally occurring and high Vitamin B12-containing plant-derived food sources showed that nori, which is formed into a sheet and dried, is the most suitable Vitamin B12 source for vegetarians presently available. Consumption of approximately 4g [being around 1.5 thin sheets of 20x20cm] of dried purple laver (Vitamin B12 content: 77.6μg/100g dry weight) supplies the RDA of 2.4 μg/day…”
Also known as “Porphyra” this kelp seaweed nori product is “also a rich source of iron and omega-3 polyunsaturated fatty acids… hand-rolled sushi made by wrapping rice and fillings with nori is easy to prepare and facilitates the consumption of a large amount of nori…”
The study also reports: “relatively high levels of Vitamin B12 were detected in the commercially available shiitake mushroom fruiting bodies, but the Vitamin B12 content significantly varies (1.3-12.7μg/100g dry weight)… the dried shiitake mushroom fruiting bodies (per 100g) contain 18.9 mg of Vitamin D2 (ergocalciferol) and 2.0 mg of iron…”
Reference: “Vitamin B12-Containing Plant Food Sources for Vegetarians”, Nutrients, 2014 May; 6(5): 1861–1873; at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042564/
In other words, from the abstract of the ‘Nutrients’ science journal: “a few plant-based foods contain substantial amounts of Vitamin B12… A survey of naturally occurring plant-derived food sources with high Vitamin B12 contents suggested that dried purple laver (nori) is the most suitable Vitamin B12 source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients… such as iron and n-3 [omega 3] polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.”
Reference: “Vitamin B12-containing plant food sources for vegetarians”, Nutrients, 2014 May 5;6(5):1861-73; at https://www.ncbi.nlm.nih.gov/pubmed/24803097
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Regards B12 in eggs and dairy milk the science journal Nutrients states: “The Vitamin B12 content is NOT high in whole eggs (approximately 0.9–1.4 μg/100 g), most of which is located in the egg yolk . The average bioavailability of Vitamin B12 from cooked eggs is 3.7%–9.2%. Thus, the Vitamin B12 in eggs is generally poorly absorbed… The Vitamin B12 content of various types of milk is very low (approximately 0.3–0.4 μg/100 g), and appreciable losses of Vitamin B12 occur during the processing of milk… The Vitamin B12 content in the whey is considerably reduced during lactic acid fermentation. These observations explain why Vitamin B12 deficiency is relatively common in lacto-ovo-vegetarians. These observations explain why Vitamin B12 deficiency is relatively common in lacto-ovo-vegetarians …
Thus, many investigators have suggested that vegetarians should maintain an adequate intake of Vitamin B12 by consuming supplements that contain Vitamin B12 or Vitamin B12-fortified foods.” (emphasis added)
Reference: “Vitamin B12-Containing Plant Food Sources for Vegetarians”, Nutrients, 2014 May; 6(5): 1861–1873; at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4042564/
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Regards B12 a 2017 report in the European Journal of Nutrition stated “deficiency of this particular vitamin was low in all groups thanks to widespread use of supplements.” The report is titled “Micronutrient status and intake in omnivores, vegetarians and vegans in Switzerland” at https://www.ncbi.nlm.nih.gov/pubmed/26502280
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Regards B12 in mushrooms the Journal of Nutritional Science and Vitaminology: “This study determined the vitamin B12 content of six wild edible mushrooms which are consumed by European vegetarians. Zero or trace levels (0.01-0.09 µg/100 g dry weight) of vitamin B12 were determined in porcini mushrooms (Boletus spp.), parasol mushrooms (Macrolepiota procera), oyster mushrooms (Pleurotus ostreatus), and black morels (Morchella conica).
By contrast, black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius) mushrooms contained considerable levels (1.09-2.65 µg/100 g dry weight) of vitamin B12.
To determine whether C. cornucopioides or C. cibarius contained vitamin B12 or other corrinoid compounds that are inactive in humans, we purified a corrinoid compound using an immunoaffinity column and identified it as vitamin B12 based on LC/ESI-MS/MS chromatograms.”
From the results section: “These results indicated that black trumpet (C cormicopioides) and golden chanterelle (C. cibarius) mushrooms contained considerable levels of authentic B12, but not pseudo B12 that is inactive in humans. Thus, black trumpet and golden chanterelle mushrooms could be useful plant B12 sources for vegetarians.
Consumption of approximately 100 g of dried black trumpet [or approximately 1 kg of fresh mushroom (moisture content of 90%)] could provide the recommended daily dietary allowance for adults (2.4 µg/d), although they would not be able to ingest such large amounts of this mushroom daily. However, a moderate mushroom intake may contribute slightly to the prevention of severe B12 deficiency in vegetarians…”
Reference: “Characterization of vitamin B12 compounds in the wild edible mushrooms black trumpet (Craterellus cornucopioides) and golden chanterelle (Cantharellus cibarius)”, J Nutr Sci Vitaminol (Tokyo). 2012;58(6):438-41; abstract at https://www.ncbi.nlm.nih.gov/pubmed/23419403 For the full report in PDF see https://www.jstage.jst.go.jp/article/jnsv/58/6/58_438/_pdf
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(Click the image to open a larger version)
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Jack Norris, Registered Dietitian: “There is nothing natural about the abomination of modern factory farming and its attempt to reduce living, feeling beings to machines. In choosing to use fortified foods or B12 supplements, vegans are taking their B12 from the same source as every other animal on the planet – micro-organisms – without causing suffering to any sentient being or causing environmental damage. Vegans using adequate amounts of fortified foods or B12 supplements are much less likely to suffer from B12 deficiency than the typical meat eater…”
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Journal of Nutritional Science and Vitaminology (2002): “Substantial amounts of vitamin B12 were found in some edible algae (green and purple lavers) and algal health food (chlorella and spirulina tablets)… Corrinoid-compounds were purified and characterized from these algae to clarify the chemical properties and bioavailability of the algal vitamin B12.
TRUE VITAMIN B12 IS THE PREDOMINATE COBAMIDE OF GREEN AND PURPLE LAVERS AND CHLORELLA TABLETS… THE RESULTS SUGGEST THAT ALGAL VITAMIN B12 IS A BIOAVAILABLE SOURCE FOR MAMMALS.
Pseudovitamin B12 (an inactive corrinoid) predominated in the spirulina tablets, which are not suitable for use as a vitamin B12 source…” (emphasis added)
Reference: “Characterization and bioavailability of vitamin B12-compounds from edible algae”, J Nutr Sci Vitaminol (Tokyo). 2002 Oct;48(5):325-31; at https://www.researchgate.net/publication/10839468_Characterization_and_Bioavailability_of_Vitamin_B12-Compounds_from_Edible_Algae
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From “Vegan B12 deficiency: putting it into perspective” a 2011 article by Dr Michael Greger MD – excerpts: “Yes, eating a healthy plant-based diet may make us “heart attack proof” but, some ask, what about vitamin B12?
So on one hand, there’s the possibility of eliminating the greatest killer in our country [heart disease], which decimates the lives and families of more than 100,000 Americans every year, at an annual cost in the hundreds of billions. But, on the other hand, we risk vitamin what deficiency? Are the defenders of the status quo seriously trying to stack a documented cure for heart disease (not to mention the reversal of diabetes, obesity, and hypertension) against some obscure B vitamin?…
B12 is made by microbes that blanket the earth… But now we chlorinate our water supply to kill off any bugs… Make no mistake: vitamin B12 is important. But so is keeping our perspective, given the millions who are crippled and die from the onslaught of chronic disease that could be prevented, stopped, and reversed with a B12-fortified, plant-based diet.”
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In regards to supplements, from the Journal American Medical Association, 2002: “Most people do not consume an optimal amount of all vitamins by diet alone… it appears prudent for all adults to take vitamin supplements…”
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From a 2000 report in the American Journal of Clinical Nutrition (AJCN): “Thirty-nine percent of subjects had plasma vitamin B-12 concentrations <258 pmol/L, 17% had concentrations <185 pmol/L, and 9% had concentrations <148 pmol/L, with little difference between age groups. Supplement users were significantly less likely than non-supplement-users to have concentrations <185 pmol/L (8% compared with 20%, respectively). Among non-supplement-users, there were significant differences between those who consumed fortified cereal >4 times/wk (12%) and those who consumed no fortified cereal (23%) and between those in the highest and those in the lowest tertile of dairy intake (13% compared with 24%, respectively), but no significant differences by meat tertile…
A commonly used clinical cutoff for low vitamin B-12 status is 148 pmol/L (200 pg/mL). However, there is evidence that the sensitivity of this clinical cutoff is poor and that many individuals with what was previously labeled low-normal status have clinical symptoms. Lindenbaum et al found responsive symptoms in individuals with plasma concentrations as high as 258 pmol/L (350 pg/mL). We therefore used 3 descriptive cutoffs: 148 pmol/L (the current clinical cutoff), 258 pmol/L (a point at which individuals may be at risk of deficiency, although further testing is needed), and 185 pmol/L (250 pg/mL; an intermediate point)…
The new recommended intake of vitamin B-12 for adults was increased to 2.4 µg/d from a 1989 recommended dietary allowance of 2.0 µg/d (13), with the added recommendation for those older than 50 y that most of this come from supplements or fortified foods…”
Reference: “Plasma vitamin B-12 concentrations relate to intake source in the Framingham Offspring Study”, Am J Clin Nutr, February 2000; vol. 71 no. 2 514-522; http://ajcn.nutrition.org/content/71/2/514.long
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“What is the best way to get vitamin B12?” Dr Michael Greger M.D. explains: “In my opinion, the easiest and cheapest way to get our B12 is to take at least 2,500 mcg (µg) cyanocobalamin once each week, ideally as a chewable, sublingual, or liquid supplement (you can’t take too much–all you get is expensive pee)… Eggs and dairy are not optimal sources of vitamin B12 because foods come as a package deal and eggs and dairy may bring along as baggage saturated fat, cholesterol, and hormones)…”
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From a 2015 report in the American Journal of Preventative Medicine: “Compared with non-vegetarians, vegetarians have an improved profile of the traditional cardiovascular disease risk factors, including serum lipids, blood pressure, serum glucose concentration, and weight status. However, not all studies that assessed cardiovascular disease incidence among vegetarians reported a protective effect. Among studies that did show a lower prevalence of circulatory health problems, the effect was not as pronounced as expected, which may be a result of poor vitamin B12 status due to a vegetarian diet. Vitamin B12 deficiency may negate the cardiovascular disease prevention benefits of vegetarian diets. In order to further reduce the risk of cardiovascular disease, vegetarians should be advised to use vitamin B12 supplements.”
Reference: “Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians?”, Am J Prev Med. 2015 Jun;48(6):e11-26; at https://www.ncbi.nlm.nih.gov/pubmed/25998928
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From a 2015 article by Dr Thomas M. Campbell, MD some excerpts:
“How much B12 should I take? For the general adult population, a daily dose of the smallest available tablet of B12 (usually 100 mcg) should be sufficient. You require just a few micrograms a day. Your body will absorb only a very small part of that pill. The reason for this low absorption is that there is only enough intrinsic factor (the body’s chemical that shuttles B12 into your gut cells) excreted per meal to absorb 2-4 micrograms of B12. In addition, your body absorbs B12 by passive absorption, but it does this with only perhaps 1% of the total dose you consume (the percentage decreases with higher dosages). I suggest a dosage just high enough to give you a nice low-average level of B12. I do not suggest B12 for anything other than to prevent deficiency.
For those with existing deficiencies or problems with absorption, you may need significantly higher doses. Please discuss this with your doctor…
What form B12 should I take?
Personally, I don’t really advise any particular form. You can take cyanocobalamin or methylcobalamin. Both have been shown to increase B12 levels. If any readers have seen primary research (ie. not a webpage like this one) that suggests a different interpretation, please let me know.
If you are concerned with deficiency or maximizing absorption, chewable or dissolvable tablets are much better absorbed. As discussed in my smoothie article that generated lots of lively debate, very important digestion starts in the mouth. This is another example…”
The full article titled “12 Questions Answered Regarding Vitamin B12” is at http://nutritionstudies.org/12-questions-answered-regarding-vitamin-b12/
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On how much B12 to take Dr Michael Greger states: “For adults under age 65, the easiest way to get B12 is to take at least one 2,500 mcg supplement each week or a daily dose of 250 mcg. Note that these doses are specific to cyanocobalamin, the preferred supplemental form of vitamin B12, as there is insufficient evidence to support the efficacy of the other forms, like methylcobalamin.
As we age, our ability to absorb vitamin B12 may decline. For those over 65 who eat plant-based diets, the supplementation should probably be increased up to 1,000 mcg of cyanocobalamin each day.
Instead of taking B12 supplements, it is possible to get sufficient amounts from B12-fortified foods, but we would have to eat three servings a day of foods each providing at least 25 percent of the Daily Value (on the Nutrition Facts label), with each serving eaten at least four to six hours after the last. For B12-fortified nutritional yeast, for example, two teaspoons three times a day would suffice. For most of us, though, it would probably be cheaper and more convenient to just take a supplement…” at https://nutritionfacts.org/topics/vitamin-b12/
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Regards B12 in Nori seaweed (also known as ‘lavers’) the British Journal of Nutrition: “The purple laver contained five types of biologically active vitamin B12 compounds (cyano-, hydroxo-, sulfito-, adenosyl- and methylcobalamin), in which the vitamin B12 coezymes (adenosyl- and methylcobalamin) comprised about 60 % of the total vitamin B12… fed the diet supplemented with dried purple laver (10 microg/kg diet) for 20 d, urinary methylmalonic acid excretion (as an index of vitamin B12 deficiency) became undetectable and hepatic vitamin B12 (especially adenosylcobalamin) levels were significantly increased. These results indicate that vitamin B12 in dried purple laver is bioavailable…”
Reference: “Feeding dried purple laver (nori) to vitamin B12-deficient rats significantly improves vitamin B12 status”, Br J Nutr. 2001 Jun;85(6):699-703; at
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“Vitamin B12 Sources and Bioavailability” is the title of a report in the science journal Experimental Biology and Medicine. An excerpt from the abstract: “vitamin B(12) bioavailability significantly decreases with increasing intake of vitamin B(12) per meal… Vitamin B(12) in eggs seems to be poorly absorbed (< 9%)… Some plant foods, dried green and purple lavers (nori) contain substantial amounts of vitamin B(12), although other edible algae contained none or only traces of vitamin B(12). Most of the edible blue-green algae (cyanobacteria) used for human supplements predominantly contain pseudovitamin B(12), which is inactive in humans… Fortified breakfast cereals are a particularly valuable source of vitamin B(12) for vegans and elderly people. Production of some vitamin B(12)-enriched vegetables is also being devised…”
And excerpts from the full report: “Considerable amounts of vitamin B12 are found in various types of tea leaves: green (0.1–0.5 ug vitamin B12 per 100 g dry weight), blue (about 0.5 ug), red (about 0.7 ug), and black (0.3–1.2 ug) tea leaves (48)… These results indicate that the vitamin B12 found in the fermented black tea is bioavailable… However, only 1–2 liters of consumption of fermented tea drink (typical regular consumption in Japan), which is equivalent to 20–40 ng vitamin B12, is not sufficient to meet the RDA of 2.4 ug/day for adult humans…
A soybean-fermented food, tempe, contains a large amount of vitamin B12 (0.7 to 8 ug/100 g; Ref. 50)… Another fermented soybean, natto, contains a minute amount of vitamin B12 (0.1 to 1.5 ug/100 g; Ref. 52)…
Dried green (Enteromorpha sp.) and purple (Porphyra sp.) lavers (nori) are the most widely consumed among the edible algae and contain substantial amounts of vitamin B12 (32 to 78 ug/100 g dry weight; Ref. 39). In Japanese cooking, several sheets of nori (9 3 3 cm; about 0.3 g each) are often served for breakfast. A large amount of nori (<6 g) can be consumed from certain sushi, vinegared rice rolled in nori. However, edible algae other than these two species contain none or only traces of vitamin B12 (39). Dagnelie et al. (53) reported the effect of edible algae on the hematologic status of vitamin B12–deficient children, suggesting that algal vitamin B12 appears to be nonbioavailable. As bioavailability of the algal vitamin B12 is not clear in humans, my colleagues and I characterized corrinoid compounds to determine whether the dried purple and green lavers and eukaryotic microalgae (Chlorella sp. and Pleurochrysis carterae) used for human food supplements contain vitamin B12 or inactive corrinoids.
My colleagues and I found that these edible algae contain a large amount of vitamin B12 without the presence of inactive corrinoids (54–57)… Rauma et al. (60) also reported that vegans consuming nori and/or chlorella had a serum vitamin B12 concentration twice as high as those not consuming these algae…
Further studies are needed to clarify bioavailability of spirulina vitamin B12 in humans… the results reviewed above indicate that edible cyanobacteria often contain a large amount of pseudovitamin B12, which is known to be biologically inactive in humans. Therefore, they are not suitable for use as a source of vitamin B12…
Several groups of investigators suggested that eating a breakfast cereal fortified with folic acid, vitamin B12, and vitamin B6 increases blood concentrations of these vitamins and decreases plasma total homocysteine concentrations in elderly populations…
Sato et al. (47) reported that a high level of vitamin B12 is incorporated
into a vegetable, kaiware daikon (radish sprout), by soaking its seeds in vitamin B12 solutions before germination. The amount of vitamin B12 incorporated into kaiware daikon increases up to about 170 ug/100 g of wet sprout with 3-hr
soaking of seeds in 200 ug/ml vitamin B12 solution. These vitamin B12–enriched vegetables may be of special benefit to vegans or elderly persons with food-bound vitamin B12 malabsorption…”
Reference: “Vitamin B12 sources and bioavailability”, Exp Biol Med (Maywood), 2007 Nov;232; at https://www.researchgate.net/publication/5885695_Vitamin_B12_Sources_and_Bioavailability (abstract only). The full report was accessed online at http://www.tier-im-fokus.ch/wp-content/uploads/2009/10/watanabe02.pdf
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From Journal of Agricultural and Food Chemistry: “plant-based foods such as certain types of dried lavers (nori) and mushrooms contain substantial and considerable amounts of vitamin B12… The majority of edible blue-green algae (cyanobacteria) and certain edible shellfish predominately contain an inactive corrinoid known as pseudovitamin B12. Various factors affect the bioactivity of vitamin B12 in foods. For example, vitamin B12 is partially degraded and loses its biological activity during cooking and storage of foods…”
Reference: “Biologically Active Vitamin B12 Compounds in Foods for Preventing Deficiency among Vegetarians and Elderly Subjects”, Journal of Agricultural and Food Chemistry, 2013 Jul 17;61(28):6769-75; at https://www.ncbi.nlm.nih.gov/pubmed/23782218
A 2013 report by the American Chemical Society (ACS) states: “published in ACS’ Journal of Agricultural and Food Chemistry, the authors say that many of the best-known sources of vitamin B12 actually contain a form of the vitamin that humans can’t use…
The scientists reviewed almost 100 scientific studies on the topic. They found that some highly touted sources of vitamin B12, such as blue-green algae called Spirulina that are sold as a dietary supplement, and some shellfish, instead contain high levels of a “pseudo” or “false” form of the vitamin that the human body can’t use.
In addition, cooking and storing foods can destroy “true” vitamin B12. Based on their review, they note that vegans could add some fermented foods, two types of edible algae, two types of mushrooms and B12-enriched vegetables to their diets to get enough of the nutrient…”
Reference: “Preventing vitamin B12 deficiency among vegetarians, vegans and the elderly, American Chemical Society (ACS) at
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This site contains pages with hundreds of science reports on the higher rates of disease & death associated with eating red meat, dairy, chicken/poultry, eggs, fish/seafood & of the lower rates associated with eating healthy plant-based diets high in fruits & vegetables & nuts.
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Dr John McDougall MD wrote in 2007: “Take a moment to compare the possible consequences of your dietary decisions. You could choose to eat lots of B12-rich animal foods and avoid the one-in-a-million chance of developing a reversible anemia and/or even less common, damage to your nervous system. However, this decision puts you at a one-in-two chance of dying prematurely from a heart attack or stroke; a one-in-seven chance of breast cancer or a one-in-six chance of prostate cancer. The same thinking results in obesity, diabetes, osteoporosis, constipation, indigestion, and arthritis. All these conditions caused by a B12-sufficient diet are found in the people you live and work with daily…
Why would a plant-food-based diet, heralded as a preventative and cure for our most common chronic diseases be deficient in any way? Such a diet appears to be the proper, intended, diet for humans, except for this one blemish. The reason for this apparent inconsistency is we now live in unnatural conditions—our surroundings have been sanitized by fanatical washing, powerful cleansers, antiseptics, and antibiotics. Since the germ theory of disease was developed by Louis Pasteur in 1877 our society has waged an all-out war on these tiny creatures—most of them extremely beneficial with only a very few acting as pathogens. The rare case of B12 deficiency may be one important consequence of too much cleanliness…
Almost all cases of vitamin B12 deficiency seen in patients today and in the past are due to diseases of the intestine, and are not due to a lack of B12 in their diet. Damage to the stomach (parietal cells) usually from an autoimmune disease or surgery halts the production of intrinsic factor. Damage to the ileum, preventing reabsorption and interrupting recirculation, causes the loss of B12. Over a period of 3 to 6 years the body’s stores of vitamin B12 are depleted. The disease that results is called pernicious anemia…
Sources of Vitamin B12:
As little as 0.3 to 0.65 micrograms per day of vitamin B12 has cured people of megaloblastic anemia; however, to add an extra margin of safety I have recommended a higher dosage of 5 micrograms per day. You may be surprised to discover that you cannot purchase these tiny dosages. Supplements sold contain 500 to 5000 micrograms per pill. These exaggerated concentrations will correct by passive absorption B12 deficiency caused by disease of the intestine. Everyone else is being overdosed by a factor of 1000. If you are an otherwise healthy vegan and are using typical dosages of B12 (500 micrograms or more per pill), a weekly dose of this vitamin will be more than sufficient.
You will often find B12 sold under its proper name. Because vitamin B12 contains one molecule of the mineral cobalt, the scientific name is Cobalamin. As a food additive and a supplement pill, vitamin B12 is usually found in the form cyanocobalamin. The effectiveness of this “cyanide complex” for treating neurologic problems has been questioned; therefore, other forms, such as methylcobalamin and hydroxycobalamin may be better choices for the prevention and treatment of B12-related conditions.
Choosing a bioactive form of B12 is important. There are many B12-like substances called analogues found in food supplements, such as spirulina and other algae—these are ineffective and should not be relied upon. Foods fermented by bacteria, such as tempeh, and miso; as well as sea vegetables (nori), have been recommended as sources of B12. Miso and tempeh do not contain B12. Nori—the dried green and purple lavers commonly used to make sushi—has been tested and found to have substantial amounts of active vitamin B12 and has been recommended a “most excellent source of vitamin B12 among edible seaweeds, especially for strict vegetarians.” (Nori obtains its B12 from symbiotic bacteria that live on it.) However, there is still some uncertainty about nori as a reliable B12 source; therefore, I suggest if you do choose this seaweed that you should monitor your B12 levels by blood tests now, and if adequate, every 3 years.
In order to minimize your risk of any health problems, I recommend you and your family follow a diet based on starches, vegetables, and fruits. To avoid the extremely rare chance of becoming a national headline, add a reliable B12 supplement.”
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From the Journal of Agricultural and Food Chemistry: “These results indicate that the dried lavers (nori) are the most excellent source of vitamin B(12) among edible seaweeds, especially for strict vegetarians…
Vitamin B(12) concentrations of dried green (Enteromorpha sp.) and purple (Porphyra sp.) lavers (nori) were determined by both Lactobacillus leichmannii ATCC 7830 microbiological and intrinsic factor chemiluminescence methods.
The values determined by using the microbiological method (63.58 +/- 2.90 and 32.26 +/- 1.61 microg/100 g of dry weight) were identical to those found by using the chemiluminescence method (69.20 +/- 2.21 and 25.07 +/- 0.54 microg/100 g of dry weight) in both dried green and purple lavers, respectively.
A silica gel 60 thin-layer chromatography of both laver extracts shows that non-coenzyme forms (hydroxo and cyano forms) of vitamin B(12) predominate in both dried lavers.
The dried lavers contained lesser amounts of dietary iodine (approximately 4-6 mg/100 g of dry weight) relative to other seaweeds, suggesting that excessive intake of the dried lavers is unlikely to result in harmful intake of dietary iodine…”
Reference: “Dried green and purple lavers (Nori) contain substantial amounts of biologically active vitamin B(12) but less of dietary iodine relative to other edible seaweeds”, J Agric Food Chem, 1999 Jun;47(6):2341-3; at https://www.ncbi.nlm.nih.gov/pubmed/10794633
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Regards Chlorella (an algae) as a bioavailable source of B12 the Journal of Medicinal Food reported in 2015: “This exploratory open-label study was performed to determine if adding 9 g of Chlorella pyrenoidosa daily could help mitigate a vitamin B12 deficiency in vegetarians and vegans… The results of this work suggest that the vitamin B12 in chlorella is bioavailable and such dietary supplementation is a natural way for vegetarians and vegans to get the vitamin B12 they need.”
Reference: “Nutritional Supplementation with Chlorella pyrenoidosa Lowers Serum Methylmalonic Acid in Vegans and Vegetarians with a Suspected Vitamin B12 Deficiency”, J Med Food. 2015 Dec;18(12):1357-62; at https://www.ncbi.nlm.nih.gov/pubmed/26485478
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The following excerpts are from an article titled “What Every Vegan Should Know about Vitamin B12” sub-titled “An Open Letter from Health Professionals and Vegan Organizations” hosted on a website “Maintained by Jack Norris, Registered Dietitian” – excerpts:
“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. Vitamin B12, whether in supplements, fortified foods, or animal products, comes from micro-organisms.
Most vegans consume enough B12 to avoid anemia and nervous system damage, but many do not get enough to minimize potential risk of heart disease or pregnancy complications.
To get the full benefit of a vegan diet, vegans should do one of the following:
– Eat fortified foods two or three times a day to get at least three micrograms (mcg or µg) of B12 a day or
– Take one B12 supplement daily providing at least 10 micrograms or
– Take a weekly B12 supplement providing at least 2000 micrograms.
If relying on fortified foods, check the labels carefully to make sure you are getting enough B12. For example, if a fortified plant milk contains 1 microgram of B12 per serving then consuming three servings a day will provide adequate vitamin B12. Others may find the use of B12 supplements more convenient and economical.
The less frequently you obtain B12 the more B12 you need to take, as B12 is best absorbed in small amounts. The recommendations above take full account of this. There is no harm in exceeding the recommended amounts or combining more than one option…
To be truly healthful, a diet must be best not just for individuals in isolation but must allow all six billion people to thrive and achieve a sustainable coexistence with the many other species that form the “living earth.” From this standpoint the natural adaptation for most (possibly all) humans in the modern world is a vegan diet. There is nothing natural about the abomination of modern factory farming and its attempt to reduce living, feeling beings to machines. In choosing to use fortified foods or B12 supplements, vegans are taking their B12 from the same source as every other animal on the planet – micro-organisms – without causing suffering to any sentient being or causing environmental damage.
Vegans using adequate amounts of fortified foods or B12 supplements are much less likely to suffer from B12 deficiency than the typical meat eater. The Institute of Medicine, in setting the US recommended intakes for B12 makes this very clear. “Because 10 to 30 percent of older people may be unable to absorb naturally occurring vitamin B12, it is advisable for those older than 50 years to meet their RDA mainly by consuming foods fortified with vitamin B12 or a vitamin B12-containing supplement.” Vegans should take this advice about 50 years younger, to the benefit of both themselves and the animals. B12 need never be a problem for well-informed vegans…”
Other articles by Jack Norris, Registered Dietitian:
“Response to: Vegan Vitamin B12 Deficiency is a Myth” at
“B12 in Plant Foods” by Jack Norris, RD at http://www.veganhealth.org/b12/plant
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From an article titled “VITAMIN B12 IN ALGAE: SPIRULINA, CHLORELLA AND NORI” the conclusion states:
“For those who are urgently seeking a plant-based source of vitamin B12, chlorella is the best current option. Whether this alga is better than regular vegan B12 supplements however is still a matter of debate. Provided that supplements contain natural forms of hydroxocobalamin and methylcobalamin, they can be considered identical to natural sources – even if the active ingredients have been chemically isolated.
The low content of B12 in chlorella unfortunately makes it impractical as the sole source of B12 for many people. Even slight absorption difficulties increase the B12 requirement by a considerable amount.
Algae are best consumed as part of a diet, which contains multiple sources of B12, such as enriched vegan products. As a result, the body’s B12 intake can be spread evenly over the course of day, allowing the body’s B12 absorption mechanism via intrinsic factor (IF) to work optimally. IF allows for around 2 µg per meal/snack to be absorbed.”
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A 2009 article in the American Journal of Clinical Nutrition states: “In large surveys in the U.S. States & the U.K. ˜6% of those aged =60 y are vitamin B-12 deficient… with the prevalence of deficiency increasing with age. Closer to 20% have marginal status… in later life. In developing countries, deficiency is much more common… in most studies, serum vitamin B-12 concentration is correlated with intake of this vitamin. In older persons, food-bound cobalamin malabsorption becomes the predominant cause of deficiency, at least in part due to gastric atrophy, but it is likely that most elderly can absorb the vitamin from fortified food. Fortification of flour with vitamin B-12 is likely to improve the status of most persons with low stores of this vitamin…
Vitamin B-12 deficiency and depletion are common in wealthier countries, particularly among the elderly, and are most prevalent in poorer populations around the world. This prevalence was underestimated in the past for several reasons, including the erroneous belief that deficiency is unlikely except in strict vegetarians or patients with pernicious anemia, and that it usually takes ˜20 y for stores of the vitamin to become depleted. This article reviews the prevalence of deficiency and its underlying causes, which is relevant to assessing the potential benefits of fortifying flour with this vitamin…”
Reference: “How common is vitamin B-12 deficiency?”, Am J Clin Nutr, February 2009, vol. 89 no.2 693S-696S; http://ajcn.nutrition.org/content/89/2/693S.full
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From a detailed article by VivaHealth titled “Vitamin B12” – excerpts: “B12 is made by bacteria in soil and water and to some extent bacteria in the gut (although production in the gut occurs in a different area to where absorption takes place). Traditionally farmed animals got B12 from eating food from the ground because B12 was in the bacteria in the soil. B12 consumed in their diet was then taken up into the cells in their bodies…
In the US, The Institute of Medicine of the National Academy of Sciences recommends that all adults over 50 years (including meat-eaters) obtain B12 from vitamin supplements or fortified foods because of the high incidence of impaired B12 absorption from animal foods in this age group (Institute Of Medicine, 1998)…
A study in Switzerland found that despite a relatively low B12 intake from food in the vegan group they looked at, deficiency of this vitamin was low thanks to the widespread use of supplements. They concluded that consuming a well-balanced diet including supplements or fortified products, all types of diet can potentially fulfil requirements for vitamin and mineral consumption (Schüpbach et al., 2015)…
Vitamin B12 in meat is bound to animal protein and so is more difficult to absorb than the unbound form produced by bacteria. B12 deficiency tends to increase with age; up to 40 per cent of the UK’s meat-eating elderly population suffers from low B12 due to a reduction in their ability to absorb this vitamin (Tucker et al., 2000). In fact, mild to moderate B12 deficiency is common in industrialised countries despite the fact that a typical western diet provides around 5-7μg B12 per day (Obeid et al., 2015). This may be explained by an age-related decrease in the ability to release B12 from animal protein or by an impaired intestinal absorption of B12…
In the elderly, a decline in the amount of acid produced in the stomach can also reduce B12 absorption; again this mainly affects B12 absorption from meat…
The [UK] Department of Health cautions that if you take vitamin B12 supplements, you should not take too much, because this could be harmful. However, the amount they say you can take before it might be harmful is substantially higher than the RNI. They say that taking 2,000μg or less a day of vitamin B12 in supplements is unlikely to cause any harm (NHS Choices, 2015a)…”
The article is at https://www.vivahealth.org.uk/resources/nutrition-%E2%80%93-what%E2%80%99s-meat-and-where-else-can-i-get-it/vitamin-b12-online
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Regards a survey of B12 in fortified foods a report in the Polish National Institute of Hygiene: “The highest amount of vitamin B12 was found in some candies (max. 4,5 microg/100 g) and instant tea (max. 3,75 microg/100g). The lowest amount was found in some fruit beverages (min. 0,12 microg/100 g). There is possibility of increasing the vitamin B12 intake by consuming various fortified products: for instance a glass of soya drink (20,8% RDA), a cup of soya pudding (15%), a glass of instant tea (14%), apple juice (12,5%), a cereal bar (10%), a bowl of corn flakes (9,8%) or a slice of bread with margarine (7,5%). The intake of one average portion of chosen food products fortified with vitamin B12 provides about 0,18-0,5 microg (7,5-20,8% Polish RDA for adults).”
Reference: “Evaluation of the needs and possibilities of increasing the vitamin B12 content in diet”, Roczniki Państwowego Zakładu Higieny (Yearbooks of the National Institute of Hygiene), 2012;63(1):67-71; at https://www.ncbi.nlm.nih.gov/pubmed/22642072
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From an article title “Eat Your Dirt: Vitamin B12” – some excerpts: “Many people believe that B12 only comes from animal flesh and animal secretions (i.e. cow’s milk, chicken eggs…) when in fact it is solely bacteria-based. Fungi, animals and plants are incapable of producing B12 on their own and must obtain it from outside sources. B12 is synthesized by bacteria and is therefore found in areas of bacterial growth, namely dirt and soil. Humans have been getting their B12 from the dirt for hundreds of thousands of years by eating plants that still had bits of soil on them. Today however, we wash our fruits and veggies so well (and understandably so) that we no longer consume dirt or proper levels of B12. That’s where supplements come in. B12 is easily produced through bacterial fermentation and can be safely made into a daily supplement.
So here’s where it gets tricky for some: If we have to take supplements, then isn’t a vegan diet unnatural? Whether you get your B12 from a pill or from eating meat, you are most likely taking supplements, and here’s why… today’s meat industry has animals locked and caged inside warehouses (yes, some of which are labeled “organic”, “free-range” and “grass-fed”) and feeds the animals mixtures of corn and various byproducts and hormones which contain no natural B12. Like us, these animals need B12 to survive and therefore are given B12 as part of their supplements, which then ends up in their milk, muscles and eggs. Doesn’t it seem easier, more humane and more natural to just take a little bacteria-based pill yourself?
B12 is needed in very small amounts, around 1.5 micrograms every day. With an absorption rate of 50%, it is recommended that most people ingest at least 3 micrograms per day to meet their daily needs. Meeting your B12 requirements is not a “vegan issue,” and vegetarians and non-vegetarians alike can easily become deficient. B12 is one of the cornerstones of life and deficiency can result in everything from lack of energy, confusion, numbness and in extreme cases, coma and death. Symptoms of B12 deficiency can take years to manifest, so even people who feel healthy may be at risk. Women who are pregnant or nursing require increased levels of B12. Meeting these needs on a plant based diet is incredibly easy with fortified foods, such as plant milks or veggie meats along with a simple B12 supplement (10 micrograms a day or 2000 micrograms a week if not relying on fortified foods to ensure proper absorption.)
There are also fantastic plant based whole foods that are sources of B12, although their ability to serve as a stand-alone source is debated. These foods include tempeh, nori, spirulina, barley grass, kombucha and everyone’s favorite, nutritional yeast. While these foods may not supply all the B12 needed on a daily basis, they are a great way to get an added nutritional boost in your diet (not to mention delicious!)
Herbivore or omnivore, everyone should be aware of their B12 intake to ensure that they are getting the most nutrition out of their diets. However, with the ease and availability of B12 supplements as well as the tasty benefits of vegan fortified and whole-food sources, go ahead and skip the middle-man, or should I say middle-cow/pig/chicken/fish, and get your B12 straight from a sprinkle of nooch, a glass of almond milk and a B12 supplement everyday!”
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From an article by Dr Gina Shaw: “I believe that Vitamin B12 deficiency is typically caused by lack of absorption in the intestinal tract rather than a lack of this vitamin in the diet... a reliance on supplements, without getting to the root of the problem isn’t ideal…”
She discusses some factors that could hamper absorption including alcohol, cooking and the use of antibiotics which contribute to “intestinal flora problems”.
She states she “does not believe that a vitamin B12 deficiency is more widespread in vegans or vegetarians – this is probably just another marketing lie! In fact, many so-called studies ‘showing vegans deficient’ have to be carefully studied themselves – many of them do not prove vegans to be deficient at all! In fact, contrary to meat and dairy industry propaganda, meat-eaters are known to be more likely to have a vitamin B12 deficiency…”
She states further that “animal and dairy produce is a poor source of Vitamin B12 since they are normally cooked and therefore 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…” Reference: http://www.vibrancyuk.com/B12.html
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“You’ll typically see two types of vitamin B12 supplements on the market: methylcobalamin… has largely been shown to be absorbed much better than other forms…” from http://www.onegreenplanet.org/natural-health/the-top-things-to-look-for-when-choosing-a-vitamin-b12-supplement/
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An article titled “What every vegan should know about B12” is at http://www.veganaustralia.org.au/b12
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This set of articles were compiled for
Pages on this Site:
Eating Meat & Dairy Increases Climate Change, Pollution & Damage to Our Environment
Quotes from news reports & science journals on how the Western omnivore diet with meat and dairy products accelerates climate-change through: i) increasing our carbon footprint of greenhouse gases; ii) deforesting & destroying wilderness that absorbs carbon and protects biodiversity; iii) creating massive pollution; and iv) wasting resources like grains, water, fuels and agricultural lands.
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Eating Meat linked to Higher Rates & Risk of Cancer, Diabetes, Heart Disease & Early Death
Excerpts & links to medical studies, articles & reports on the links between meat consumption and increased incidences of cancer, heart disease, diabetes and early mortality (a shorter lifespan); also to reports on how cancers are increasing in young people.
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Scientific Studies on Health Advantages of Vegans & Vegetarians
Quotes & links to articles in science, medical & health journals that report great benefits vegetarians and vegans generally have including longer lives with less of the chronic degenerative diseases like cancer, cardiovascular heart disease, diabetes, osteoporosis and obesity as well as lower blood pressure, hypertension and blood cholesterol levels.
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Mass Extinction Loss of Biodiversity caused by Humans
Excerpts & links to articles in news media science journals about the current ‘Sixth Mass Extinction’ known also as the ‘Holocene Extinction’ or ‘Anthropocene Extinction’ as it is largely caused by human activities.
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Dairy Milk Health Problems – Issues & Risks for Related Disease & Illness
This page contains quotes & links for studies & articles in science journals, news media & by medical doctors; on the association of drinking milk to higher rates of osteoporosis, cancer, heart disease and other illnesses.
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Risk of Infectious Disease Epidemics from Antibiotic-resistant Bacteria due to Animal Agriculture
This page features quotes & links to articles in news media and science journals about the rise of microbes that are resistant to antibiotics; posing a grave threat to all of us; from 50% to 80% of antibiotics are (mis-)used in animal agriculture industries.
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How the Meat & Dairy Industry Influences Politics, Government, Education, News & Media
This page features quotes & links to reports that expose how the animal agriculture industries (meat, dairy, poultry) influence government, politics, the education schooling system and news media in order to promote their interests.
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Eating Seafood & Overfishing is Destroying Oceans, Rivers & Wildlife
Excerpts from articles about the marine ecosystem collapse that is happening now in oceans, seas & rivers due to over-fishing and the toxic pollution in waterways from land-based animal agriculture meat-farming; worsening climate change; threatening the entire food chain.
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Studies Find Eating Fish Seafood Not So Healthy With Raised Risks of Disease
Articles from science journals & news reports that dispute the health claims made regards eating fish; some even find higher rates of heart disease and cancer among seafood consumers.
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Are Soy Foods Healthy or Not? Doctors & Nutrition Experts Refute Some Myths
A collection of quotes & links for articles by doctors, dietitians & nutrition experts who refute & rebut the negative claims made regards “the soy food debate”
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For Archives of Related Memes see:
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How We Are Eating Our Future
This site’s original 2012 page with excerpts from articles in science journals and news media about how what we choose to eat can: i) accelerate or slow down climate change and the related environmental catastrophes we face; and ii) increase or reduce our risks for chronic illness and disease. The evidence and body of opinion against the animal agriculture livestock industry is particularly compelling and damning.
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