Talk:Vitamin B12/Archive 2

Archive 1

Archive 2

Archive 3

Off topic chat

Off-topic chat

Vegan Sources of B12 Koreans maintain that kimchi is a great source of B12. Kimchi is made from fermented vegetables, so can it replace supplements for vegans? Or is the B12 that it contains the Pseudo B12 mentioned in the article? [1] —Preceding unsigned comment added by 149.99.63.218 (talk) 18:11, 5 September 2008 (UTC) Hard to say from the literature. Kimchi is made in many ways with hundreds of different strains of bacteria. Some of them probably produce useable B12. People have tried to ensure that B12 is produced by innoculating the stuff with Propionibacterium Freudenreichii. I'm not sure it's worth the effort. Vegans can simply take vegan B12 tablets with vitamin produced by other bacteria. You can't GET B12 supplements in high strength which aren't produced by bacteria, and thus vegetarian. SBHarris 05:16, 6 September 2008 (UTC) Sbharris, your tongue slipped on vegetarian/vegan :-). 64.56.229.166 (talk) 00:04, 20 April 2009 (UTC) Yes, well, bacteria and their products (e.g. Xanthan gum) are both vegetarian AND vegan. SBHarris 18:31, 13 October 2010 (UTC) Just as a sidenote here: B12 supplements are generally considered very safe and you shouldn't have to worry about taking too much, as oral supplements at least. (scroll down to "Vitamin B12") So if you are looking to non-supplement sources such as the vegetable in question here (if it is a source), as an alternative to B12 supplements (sprays and pills), if you are concerned about safety or effectiveness, you can safely toss those worries away. :) Just make sure you get your B12! Otherwise bad stuff may happen, or really bad, if you are a pregnant woman... — Preceding unsigned comment added by 94.22.26.213 (talk) 18:37, 20 February 2016 (UTC)

Toxicity?

Linus Pauling site says that doses up to 1000 µg per day show no toxicity symptoms. Some energy supplement drinks, have large doses. The Zipfizz® energy drink mix label says it has 2500 µg per serving. Are we damaging something by ingesting 2 or 3 of these drinks per day? Or does the excess just get harmlessly flushed out? pechaney (talk) 01:45, 11 August 2008 (UTC)

Good Question 1 I was told i had Peripheral Neuropathy 4 years ago. My primary care physician suggested a regemin of b12. I found the Jarrow Formula 5,000mcg sublinguals online for like $5.00 a bottle. I bought a few dozen bottles and ate them like candy for a year. I would say that on average I was taking 15,000 mcg per day for at least 6 months. I had improvement, then a huge Neurological and gastrointestinal Breakdown a year ago.. The workup is in progress. Cleveland and Mayo Clinics are working on me. Perhaps I will be the poster child for b12 toxicity.. —Preceding unsigned comment added by 208.62.29.156 (talk) 22:05, 14 September 2008 (UTC)

you sir deserve a darwin award! --UltraMagnus (talk) 22:39, 14 September 2008 (UTC)

Yes, neither the U.S. nor Europe have established a UL (Tolerable Upper Intake Level), but is still worrisome that the dietary supplement industry (at least in the U.S.) takes this as carte blanche to create products that have ridiculous multiples of the RDA of 2.4 mcg. Most of the products in the U.S. are in the range of 500-1000 mcg, but more than a handful offer 5000 mcg. David notMD (talk) 02:11, 27 February 2016 (UTC)

Vitamin B12 ranges

It would be helpful - especially in the context of Vit B12 deficiency - if this article included ranges for normal and deficient B12.Penelope Gordon (talk) 04:22, 22 July 2015 (UTC)

There is a problem with interpreting blood test results. According to the DRI text (ref #14) blood concentrations (either serum or plasma) under 120 pmol/L (alternative units 170 pg/mL) are considered deficient, but the body may deplete tissue levels to sustain circulating levels. Thus a low blood result may indicate a deficiency of long duration, but a higher level does not automatically mean that the person has sufficient amounts stored in organs such as the liver. David notMD (talk) 02:33, 27 February 2016 (UTC)

Termites

Termites contain B12 because B12 is contained in all animal food sources. How is this relevant or interesting? I move to delete this.--Gak 15:59, 11 September 2006 (UTC)

I disagree. The section is Sources of B12. Following this line of thought one should delete the references to eggs, dairy etc. too. Just leave a reference that says B12 is contained in all animal food sources (I bet you will have trouble finding a reference for that blanket statement). As to the relevance: Do insects contain B12? yes. Has it been scientifically measured? yes. It this quantity of B12 significant? (see reference). Granted you may not find this interesting (so rephrase), but it is relevant, because they contain B12 and this is a section on Sources of B12. --Mig77^(t) 10:42, 12 September 2006 (UTC)

I disagree with the disagree, and so have removed the sentence pertaining to termites. The section head is Miscellaneous Food Sources, not Sources of B12. I suppose in theory people can eat termites, but not me. Termites may be a significant source of vitamin B12 for chimpanzees, but that is beyond the scope of this Wikipedia entry.David notMD (talk) 03:19, 28 February 2016 (UTC)

Testing

Article needs a section about testing for B12: how it's done, what are the different measures, what can interfere with it, etc. -- Dougher (talk) 01:32, 6 June 2012 (UTC)

See comment (below) in vitamin B12 ranges. Briefly, blood tests showing low are indicative of deficiency, but can be in normal range and the person still deficient. Serum B12 is not part of a normal blood test, but may be done if there is a low red blood cell count, to help identify the cause of anemia. Doctor may also order serum homocysteine test, as this is elevated when B12 low.David notMD (talk) 21:35, 27 February 2016 (UTC)

Where does the chicken get it?

Where does the chicken get it's B₁₂, to put it into the egg?

Oh, yes and where do the animals take their B₁₂ to put it in their meat? It sounds a bit inconsistent to me. -- anonymouse

Animals don't make B12 either, they get it by eating dirt which contains the bacteria which makes it. It's more abundant in natural, healthy soils. B12 for supplements and fortification is cultured from those same bacteria - grown in large vats.

This argument is very weak, plants get all they need from soil, sunlight, and water, planting a person would be pretty ineffective even though they would have all the elements that a plant requires to grow. The fact is that human beings cannot synthesize B₁₂, period. I assume the chicken gets the B₁₂ where we do, microscopic organisms. These are found naturally in our guts, and in the soil. Unfortunately in our guts they are too far down the digestive tract for proper B12 absorption. I am not sure if any animals are capable of B12 synthesis. (P.S. I am vegeterian so I worry about B₁₂ --Mig77 09:52, 18 May 2006 (UTC)

Please read section two (2) of this link EZNC. That should explain where cows, and possibly other animals get their B12 from. Thanks. C3045051 05:03, 19 August 2006 (UTC)

>>Hi In the "sources" part I took out the bit about bacterial contamination. I think this is very confusing; it sounds like the meat itself is covered with bacteria containing B12! The best source of B12 is from animal products, and as for where the animals get it from....this should go somewhere else, maybe under synthesis, or create a new paragraph. I also think the paragraph "B12 deficiency is very common" should go under the deficiency paragraph. Juliakbird 19:07, 6 August 2007 (UTC)

Free range chickens eat insects in addition to seeds. Industry-raised chickens are fed a product that contains 10-20 micrograms of B12 (as cyanocobalamin) per kilogram of food. Poultry feed also fortified with other vitamins and with minerals. B12 ends up in the eggs. Lowering B12 content of the feed results in smaller eggs and less B12 per egg.David notMD (talk) 16:54, 2 March 2016 (UTC)

The topic and its non-animal/pseudo-animal sources.......

• http://ebm.rsmjournals.com/cgi/content/abstract/232/10/1266
• http://www.jstage.jst.go.jp/article/bbb/66/1/66_195/_article/-char/en
• http://www.nature.com/nature/journal/v438/n7064/abs/nature04056.html
• http://pubs.acs.org/doi/abs/10.1021/jf970807j
• http://pubs.acs.org/doi/abs/10.1021/jf0101556
• http://www.ncbi.nlm.nih.gov/pubmed/20108213
• http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=anm44229
• http://scholar.google.com.hk/scholar?hl=en&q=Pleurochrysis+carterae+B12&btnG=Search&as_sdt=2000&as_ylo=&as_vis=0

--222.67.200.238 (talk) 02:20, 6 April 2010 (UTC)

• http://scholar.google.com.hk/scholar?as_q=Brachionus+plicatilis+B12&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=title&as_sauthors=&as_publication=&as_ylo=&as_yhi=&as_sdt=1.&as_sdtp=on&as_sdts=5&hl=en

--222.67.200.238 (talk) 02:34, 6 April 2010 (UTC)

• http://www.jstor.org/pss/1548225

--222.67.200.238 (talk) 02:41, 6 April 2010 (UTC)

---

• http://scholar.google.com.hk/scholar?hl=en&q=cobalamin+auxotrophs+algal&btnG=Search&as_sdt=2000&as_ylo=&as_vis=0

--222.67.200.238 (talk) 02:49, 6 April 2010 (UTC)

• http://scholar.google.com.hk/scholar?hl=en&as_sdt=2000&q=cobalamin+auxotrophs+algae

--222.67.200.238 (talk) 02:50, 6 April 2010 (UTC)

Bacteria produce b-12 found in non-animal foods. "Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus)." [Koyyalamudi SR] J Agric Food Chem. 2009, found that:—

HPLC and mass spectrometry showed vitamin B(12) retention time and mass spectra identical to those of the standard vitamin B(12) and those of food products including beef, beef liver, salmon, egg, and milk but not of the pseudovitamin B(12), an inactive corrinoid in humans. The results suggest that the consumer may benefit from the consumption of mushroom to increase intake of this vitamin in the diet.

Kombucha contains b-12, as discussed in "A Review on Kombucha Tea—Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus" [Jayabalan] (2014), citing "Mineral and water soluble vitamin content in the Kombucha drink" [Bauer-Petrovska and Petrushevska-Tozi] (2000), which found:—

Identified soluble vitamins in the Kombucha drink were quantified in the following mean concentration values: vitamin B1 0.74 mg mL, vitamin B6 0.52 mg mL, vitamin B12 0.84 mg mL, and vitamin C 1.51 mg mL, Vitamin C concentration of 1.61 mg L,obtained by Tillmans’s method.

Xkit (talk) 19:42, 11 March 2016 (UTC)

Elevated B12 missing

I was surprised there is nothing about elevated b12 and its role in disease states. Low is covered, dose is talked about, but there isn't anything about elevated b12.It appears there is a strong correlation between too high b12 as a sign of some serious illnesses. Unfortunately, I'm only discovering this through recent research and don't think I could properly sum up the issue. — Preceding unsigned comment added by 65.30.57.79 (talk) 05:07, 30 April 2015 (UTC)

Please give us or me the links you currently have. And links of elevated levels of other vitamins, expect Vitamin D3 everyone knows already. Thanks in advance! ee1518 (talk) 12:06, 7 August 2015 (UTC)

I have added such a section. The last cite in the section is a pretty good review. SBHarris 03:13, 12 March 2016 (UTC)

Excellent, thank you. https://en.wikipedia.org/wiki/Vitamin_B12#Elevated_plasma_B12_.28cobalamin.29_levels

We still need some information about B12 supplements: is the optimal amount of B12 in blood known?

It may be that only B12-TC2 test gives reliable answers: http://www.veganhealth.org/b12/levels Very low B12-TC2 statistically means very high Homocysteine. High Homocysteine may be bad for health. Unfortunately, there is no hard evidence, like mortality or cardiovascular events in this table. Table 1. Transcobalamin II Levels in Herrman et al. 2003 Study. ee1518 (talk) 11:52, 15 April 2016 (UTC)

Dietary Reference Intakes

I am creating the same format for DRIs for all B vitamins. That is a U.S.- based system that identifies Estimated Average Requirements (EARs), Recommended Dietary Allowances (RDAs), Adequate Intakes (AIs) if there is not enough information to establish EARs and RDAs, and Tolerable Upper Intake Levels (ULs). Another major regulatory agency that has established ULs is the European Food Safety Authority (EFSA). ULs for both are provided, as they often differ. If there is a UL (for some vitamins none has been determined) then rationale is covered in a Toxicity section. In addition to DRIs, the U.S. also established Daily Value, using it on food and dietary supplement labels as % DV. DVs were based on older RDAs, but as of May 2016 have been updated. What I have written can be improved. It lacks EFSA or other major country RDAs. It lacks an estimate of what percentages of people are deficient - although that is often covered in a separate section on deficiency and consequences of deficiency. I am creating this Subject in all of the Talk pages of the vitamin entries I have edited. Comments and improvements are welcome.David notMD (talk) 11:23, 21 May 2016 (UTC)

Detoxifying the CN group in the Cyano- form of cobalamin

In the article, there is mention of the fact that the Cyano- form of Cobalamin does contain the CN molecule, but it is only present in very small quantities. That's true, but the body actually produces an enzyme, Rhodanase, which detoxifies the CN by converting it to thiocyanate. Thinking this should be included in the Article (see the Wiki Article on Rhodanese.)BarkBark (talk) 23:21, 16 March 2016 (UTC)

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Clarify: Co-enzyme?

Through most of the article, B-12 is referred to as a "vitamin", but suddenly in "Mechanism of action" we get "Coenzyme B₁₂'s reactive C-Co bond participates in three main types of enzyme-catalyzed reactions." From context I assume that means that B-12 can also be characterized as a co-enzyme, but I don't know what that is, and I'm not sure because "co-enzyme" makes me think of a counterpart chemical. Can someone who knows the terminology clarify either the intro of that section or the intro of the whole article to explain or at least introduce this concept? -- Phyzome is Tim McCormack 04:50, 27 July 2016 (UTC)

Done.David notMD (talk) 15:50, 28 July 2016 (UTC)

B12 figures

Methylcobalamin tablets

The article would be better served if the First image was simply of the Over-the-Counter Vitamins. They are Readily Available at most Grocery and pharmacy stores. The Vitamin B12 is a biochemical metabolite, and the article should illustrate that by showing those pathways in greater detail.

Both of the figures presented on the webpage are nearly obscene. A free base of the methyl-form is not appropriate for academic purposes, outside of chemistry. The picture of an injection is also rarely appropriate to the public space. We should not include harmful images in this way. As it stands, it looks as if Wikipedia promotes injecting toxic chemicals.

The files I uploaded from the public webpage www.b12-vitamin.com should apply under fair use. Images of the pills would be much more appropriate than the free radical.

Also, The interaction section is too long, and albeit helpful for some people, would most likely cause users to panic. The vitamins are otc and GRAS. There is no reason to present the biochemical as a toxin. Please revise your B pages, they could be much more lively.

Also, 4 references are hardly necessary for stating that injections are used to treat genetic disorders. One general reference would be more appropriate. 216.69.46.16 (talk)Pops — Preceding unsigned comment added by 216.69.46.16 (talk) 18:12, 11 October 2016 (UTC)

There is an image of a blister-pack on Commons. Do we need four references? Probably not. Does anyone care enough to figure out which source is best and delete the others? Also probably not. Sizeofint (talk) 18:38, 11 October 2016 (UTC)

I do not think the b12-vitamin.com image can be included since it would be easy to create an appropriately licensed image. The image of the vitamin prepared for injection is clearly a medical preparation (the box even says for prescription only). I do not view it as "nearly obscene" or harmful at all. An argument can be made that other forms are more common and should be given more weight in terms of images. On the other hand, an image of generic pills isn't very informative.

Yes, this page could use improvement. It requires someone with the time, knowledge, and willingness to update it though. Any updates should preserve and/or update the content that should be included and remove content that should not be included. I would imagine the interactions section will have to source from reliable medical sources which is a higher bar than normal reliable sources. Sizeofint (talk) 01:29, 12 October 2016 (UTC)

Not obscene, but definitely extraneous, if an image of the natural vitamin is unavailable.

And since the image was from the domain "b12-vitamin.com" it should fall under fair use. I find it hard to imagine that nobody can find an appropriate image.

Tim2view (talk)Tim2view —Preceding undated comment added 19:04, 14 October 2016 (UTC)

Reason for the name

In the lead, it states that Vitamin B12 is one of eight B vitamins. If so, why is it called "B12?" I presume that there's a good reason, but it's never explained. Adding a brief explanation to the History section would improve the article because it wouldn't leave this question hanging. JDZeff (talk) 00:12, 6 October 2016 (UTC)

IMO too trivial for the article. Adenine was called vitamin B4 for a while. Ditto Inositol called vitamin B8 until it was clear that it was not essential. Could not find any info on B10. A vanishing small number of science journal articles call folate vitamin B11, whereas large numbers call folic acid vitamin B9.David notMD (talk) 17:45, 14 March 2017 (UTC)

Interactions

This section focused on bad interactions with other drugs and pharmaceuticals . It may include some interactions with cholesterol or GI meds, but the focus should be mainly on Folate and other readily available OTCs. I erased the harmful parts, but a rework should be considered.

If there is a general malabsorption condition, it should be noted in the article and not under an obscure acid. Neomycin is not an ingestible drug. If there are antibiotics that produce some interaction, this is the job of doctors to know not a wikipedia article.

We could still include the brand name pharmaceuticals, but they should be listed more clearly, under the heading pharmaceuticals. — Preceding unsigned comment added by Tim2view (talk • contribs) 19:46, 11 October 2016 (UTC)

That section is basically entirely unreferenced so probably a lot of it needs to go. It should all be sourced with WP:MEDRS. I'm not familiar enough with B12 to know what should stay and what should go. I'll see if some other editors might be willing to take a look. Sizeofint (talk) 01:37, 12 October 2016 (UTC)

From where do animals get their B12 please?

In the article as of 2017-01-16:

> No fungi, plants, nor animals (including humans) are capable of producing vitamin B12. Only bacteria and archaea have the enzymes needed for its synthesis. Proved sources of B12 are animal products (meat, fish, dairy products) and supplements.

So from where do the animals get their B12 please? — Preceding unsigned comment added by 86.136.95.253 (talk) 11:02, 16 January 2017 (UTC)

From bacteria and archaea. In fact, the human digestive system has microbes producing b12, too far down to be absorbed though. (Some fringe vegan/fruitarian sources misinterpret this as meaning humans do not need dietary b12.)

A study that used to be in the article showed that humans fed a diet deficient in b12 could maintain their blood levels through supplements made from their own poop (yum! science!). Ever walk through a cow pasture? (Watch your step!) Imagine you are a cow grazing in that field or a chicken pecking for seeds...

To add any of this loveliness to the article, we would need a reliable source discussing it. Let us nhow if you find anything. - SummerPhD^v2.0 17:49, 16 January 2017 (UTC)

I have added a sourced explanation. I have tagged the source, the T. Colin Campbell Center for Nutrition Studies, as needing a better source. While T. Colin Campbell and his foundation are likely reliable sources for this particular information, some information from the Center (particularly interpretation of the China Study) is colored in such a way as to emphasize some of the more dramatic findings. - SummerPhD^v2.0 23:54, 16 January 2017 (UTC)

Jytdog: Please review my comment above. I have little doubt that the foundation is in any way unreliable or conflicted for this basic information.

This article (not particularly reliable in and of itself) gives much the same info, with some decent cites. Citing those individual sources seems cumbersome for something so basic, but it's a decent fallback, I guess.

I am rather skeptical that we will find a journal article discuss animals' sources in general. More likely I expect we would end up with a Frankensteined section citing various articles discussing individual species or, if we are lucky, "some rodents", "livestock birds" and such.

Thoughts? - SummerPhD^v2.0 03:24, 17 January 2017 (UTC)

in these diffs i made this less human-centric and added other sources, like feces and insects. Jytdog (talk) 03:33, 17 January 2017 (UTC)

That was after I started to write my comment. Thanks. I've made a minor tweak to clarify that insects are animals. - SummerPhD^v2.0 03:46, 17 January 2017 (UTC)

fixed that, thx Jytdog (talk) 04:14, 17 January 2017 (UTC)

Yesterday I wrote:

> So from where do the animals get their B12 please?

Thank you to everyone who has participated in this discussion. — Preceding unsigned comment added by 86.173.129.111 (talk) 15:28, 17 January 2017 (UTC)

Common high-content food sources in the lede

This section has been debated:

Substantial sources of B₁₂ include animal products (shellfish, meat), mushrooms, fermented beans and vegetables, edible algae (seaweed), fortified food products, and dietary supplements.

The main source of this content information is the USDA National Nutrient Database summarized by the Nutrition Data and Linus Pauling Institute sources. Shellfish and meat are clearly among the top 50 sources shown here whereas the other sources mentioned above, excluding fortified food and supplements, are not ranked as high sources. MOS:INTRO states "According to the policy on due weight, emphasis given to material should reflect its relative importance to the subject, according to published reliable sources. This is true for both the lead and the body of the article." There is no evidence that mushrooms and seaweed are as commonly eaten as shellfish and various meats, nor is there an independent source as credible as the USDA for assessing B12 levels. Mentioning these less common foods in the lede is WP:UNDUE, as described under Relative emphasis in MOS:INTRO. It is alright to include the alternate foods under the Foods section, as shown in my revisions. --Zefr (talk) 03:01, 6 April 2017 (UTC)

This is the USDA ranked list of foods containing B12 from highest to lowest. Mushrooms, seaweed and fermented foods are not in the top 100, --Zefr (talk) 03:13, 6 April 2017 (UTC)

The top 50 sources listed by the USDA are flooded with a handful of sources repeated over in varying cooking styles. It excludes many plant sources which have been found to contain 'signifiant' amounts of B12 (as per the cited Orogen State link). To rely solely on a USDA citation while pushing studies that have additional findings to the periphery goes against the principle of a unbiased overview. As for the credibility of the USDA, it is heavily lobbied by (and has a revolving door relationship with) the Animal Agriculture industry so it's reasonable to assume that many publishings end up in favour of their industry at the expense of balanced facts. The inclusion of those proven plant sources is both relevant and it does not take up excessive space in the overview. Cyrus Freedman (talk) 03:49, 6 April 2017 (UTC)

You could derive other sources from hundreds of lower ranked foods by focusing on the actual content. There are few reliable sources of measuring nutrient content in various foods, and none regarded higher anywhere in the world than the USDA lists. Most Wikipedia articles where nutrient tables are included use the USDA database. Any argument to the contrary is WP:SOAP. The proposed discussion of mushrooms-seaweed-fermented foods-spirulina as high content foods has no source that meets WP:SCIRS. Until a solid secondary source is used to support such a statement, I am removing them from the article. Further discussion with Cyrus Freedman is here. --Zefr (talk) 04:11, 6 April 2017 (UTC)

The source for the relevance of mushrooms, algae, and fermented foods is already included as it was apart of the previously cited Oregon State study here (under the Food section). To include animal products while ignoring plant sources found in the same citation is to cherry pick of the data - resulting in a biased lede. — Preceding unsigned comment added by Cyrus Freedman (talk • contribs) 04:41, 6 April 2017 (UTC)

You have to pay attention to the actual content reported in microg per 100 g sample to emphasize a food source in the lede. --Zefr (talk) 04:45, 6 April 2017 (UTC)

The USDA citation does not show 100 g sampeles of plant or animal sources, only 3, 8, and 1 oz samples and among those none of the plant measurementes were shown. The included graph is a mere summary of the μg measurments in animal products. The lack of evidence in their graph does not prove low μg in plant sources.Cyrus Freedman (talk) 07:53, 6 April 2017 (UTC)

The USDA database of food listings for vitamin B12 content here is a report from highest to lowest per 100 gram samples. Animal sources are shown on the high-content list because B12 is present in various muscles and organs of shellfish and animals humans eat. Plant sources are not listed among the top several hundred sources because plants do not synthesize vitamin B12, as the article states. Re-read the article to understand this. Fyi, this is a list only of vegetables, showing mostly absence of B12. This is the report showing zero B12 content in kelp. The USDA database can be used by pick lists to show B12 content for many raw and processed mushrooms; I found none that contain B12. --Zefr (talk) 15:14, 6 April 2017 (UTC)

In light of the recently cited data on specific amounts of B12 per 100g, it seems fitting to add Seaweed to the lede since it has levels up to 134µg per 100g (which is considerably higher than the average animal product) and is consumered regularly (particularly in coastal regions) along with mushrooms, and fermented beans and vegitables since all three catagories contain B12 levels higher than the daily recomended amount of 2.4µg (up to 3 µg and up to 8 µg respectively).Cyrus Freedman (talk) 23:33, 7 April 2017 (UTC)

Disagree. Among all the food sources discussed, seaweed is the only one that is consumed dried. Drying from a water content of 82% to less than 10% water artificially accentuates the "apparent" nutrient density by 8 times, indicating that seaweed is a negligible source of B12 when raw. Further, the B12 contents for seaweed, mushrooms and fermented vegetables (note spelling) are based on 100 g amounts which are atypical serving sizes for these less-than-common foods. Seaweed (dried) is of interest mainly as a novelty supplement or specialty garnish which most of the English-speaking world and Wikipedia users would not have access to consume from the usual food supply. Conclusion: not lede material. --Zefr (talk) 00:00, 8 April 2017 (UTC)

Even if the seaweed was measured as wet, that's 16.75mg of B12 which far exceeds the daily reccomended amount of 2.4mg. Even if these last three plant sources are eaten sparingly, the amount needed to reach a dialy recommended amount is >100g (>0.22lbs) for all of them so it's content is substantial in diets where these foods are mere side dishes, condiments, or minor ingedients. If there's anything 'atypical' about the 100g consumption level is that it is much lower than what is typically used. Commonality of a food has to take a global view, not just that of a rural/suburban mainland american diet. Seaweed in it's raw dried form is present in almost every grocery store accross the US (along with mushrooms and fermented vegitables). Cyrus Freedman (talk) 00:12, 8 April 2017 (UTC)

Even if 16.8 ug for raw seaweed is accurate – and I have doubts about that number, as the method may not be the same as used by USDA – it's not even in the top 60 of the B12 rankings. Here are all the seaweed products measured by USDA. If B12 is absent from being included, that means the measurement was zero or not warranted for the report. Let's keep in mind that the lede addresses the major points of the article. Uncommon foods are not in that category. --Zefr (talk) 00:25, 8 April 2017 (UTC)

In the interest of a unbiased lede, all evidence backed sources should be included and appeals to the authority of favourite sources should be avoided. Until there is evidence that the results were unscientific, there is no reason to doubt the Japanese scientists who found them. The lack of evidence from the USDA could be for any number of reasons including not having seen the relivant study or by arbitrary ommition. Currently the lede is leaning on a extremely narrow bias.Cyrus Freedman (talk) 00:46, 8 April 2017 (UTC)

Incorrect. MOS:LEAD: "The lead should stand on its own as a concise overview of the article's topic. It should identify the topic, establish context, explain why the topic is notable, and summarize the most important points. The foods you are pushing are not notable and not among the most important. That's enough discussion on this. Please move on. --Zefr (talk) 00:50, 8 April 2017 (UTC)

It's only not notable if you take a narrow narcissistic american mainland view of diet. The listed plant sources of foods are extremely common, seaweed more so on the coasts but it is available in almost all mainland grocery stores in specialty sections and in ubiquitous sushi sections, and the levels of B12 in all four of them are so high that only small amounts (>0.22lbs) of them need to be consumed to reach the daily amount of B12 reccomended.Cyrus Freedman (talk) 00:58, 8 April 2017 (UTC)

"Products of animal origin constitute the primary source of vitamin B12. Older individuals and vegans are advised to use vitamin B12 fortified foods and supplements to meet their needs."

"Vitamin B12 is present in animal products, such as meat, poultry, fish (including shellfish), and to a lesser extent dairy products and eggs (1). Fresh pasteurized milk contains 0.9 μg per cup and is an important source of vitamin B12 for some vegetarians (17). Those strict vegetarians who eat no animal products (vegans) need supplemental vitamin B12 to meet their requirements. Recent analyses revealed that some plant-source foods, such as certain fermented beans and vegetables and edible algae and mushrooms, contain substantial amounts of bioactive vitamin B12 (81). Together with B-vitamin fortified food and supplements, these foods may contribute, though modestly, to prevent vitamin B12 deficiency in individuals consuming vegetarian diets."

The "narrow narcissistic american mainland view of diet" -- that the primary source of B12 for humans is animal-based foods -- seems to be the consensus, as presented in the source you cited. You seem to have a strong opinion on the subject. I'd suspect we might need some more voices here. I would like to suggest a request for comments here. - SummerPhD^v2.0 01:39, 8 April 2017 (UTC)

Chinese (take-away) dishes of seaweed are very common throughout Europe and Asia; Welsh laverbread contains seaweed; many Japanese dishes contain seaweed (some fermented); Korean dishes of seaweeds are common. Coastal communities add foraged seaweeds for extra "umami" to many dishes. Mushrooms are foraged particularly in Northern and Eastern Europe, and in Asia, and are consumed more commonly than perhaps in North America. Shellfish are uncommon food sources in most of the parts of Africa I am familiar with, and many countries in Africa don't have access to seaweeds. Wikipedia can be pretty North American centred. — Preceding unsigned comment added by 86.9.126.106 (talk) 14:10, 29 August 2017 (UTC)

The independent reliable sources that we have clearly state that the primary source of B12 for humans is animal-based foods. We do not have such sources stating that the primary sources are mushrooms and bread with seaweed. - SummerPhD^v2.0 16:58, 29 August 2017 (UTC)

Safety?

Probably premature to incorporate into the article, but an August 2017 epidemiology article reported that supplemental B12 increased risk of lung cancer. In men but not women. Effect larger in men who smoked tobacco. This was not a randomized controlled trial, so weakness is that men who chose to consume a B12 supplement may have been doing so for undiagnosed health problems that were later diagnosed as lung cancer. There is not much else in the literature on B12 and any type of cancer, or all-cause mortality. David notMD (talk) 13:38, 28 August 2017 (UTC)

Brasky TM, White E, Chen CL. Long-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) Cohort. J Clin Oncol. 2017 Aug 22:JCO2017727735. doi:10.1200/JCO.2017.72.7735. [Epub ahead of print] PubMed PMID: 28829668.

Because of the types of issues you mention, that is why we generally consider published studies to be primary sources and generally don't use them (as you are likely aware; this comment was for the benefit of others reading). That said, surely there must be studies on the use of B12 supplementation re folate, vegetarians/vegans, the elderly, Alzheimer's etc.? Or do you mean general population? - SummerPhD^v2.0 16:26, 28 August 2017 (UTC)

There are meta-analyses and systemic reviews for impact of vitamin B12 (with or without folate) on homocysteine and clinical outcomes in cardiovascular and dementia disease, with mixed results. My opinion is too small and/or too short to pick up a subtle impact on cancer risk, especially if Brasky's observation that perhaps only males and higher risk in smokers. This Cochrane review reported no significant increase in cancer from homocysteine-lowering vitamins, but any subtle effect might have been undetected when all cancers and both sexes pooled. David notMD (talk) 22:13, 28 August 2017 (UTC)

Martí-Carvajal AJ, Solà I, Lathyris D. Homocysteine-lowering interventions for preventing cardiovascular events. Cochrane Database Syst Rev. 2015 Jan 15;1:CD006612. doi: 10.1002/14651858.CD006612.pub4. Review. PubMed PMID: 25590290.

Location of B12 deficiency section

This section has recently been moved from being a subsection under Medical uses to being separate section. I think this is a definite improvement. But I suggest a different location in the article than where it is now, and that is after Sources, Biochemistry, and Physiology: deficiency can only be understood on a background of these three subjects. My support for this placement comes from WPMOS, as follows: "The given order of sections is also encouraged but may be varied, particularly if that helps your article progressively develop concepts... Do not discourage potential readers by placing a highly technical section near the start of your article... (If a condition)... depends heavily on understanding the cause, pathogenesis or symptoms, then that section may be better moved to later in the article."

I think that advice applies here, so I am retaining the suggested Section status, and am moving the section to after Physiology. Regards, IiKkEe (talk) 16:54, 14 May 2018 (UTC)

Repetition in Deficiency section and in citations

The deficiency section's text appears twice. The repeated text contains different citation numbers, but the different numbers cite the same sources. Intlitvak (talk) 23:39, 15 May 2018 (UTC)

Have removed the repetition. Thanks --Iztwoz (talk) 22:18, 17 May 2018 (UTC)

1934 Nobel Prize

Whipple, Minot, and Murphy winning the 1934 Nobel Prize is mentioned twice, but in the years 1928, 1929. If it meant to say they started research in 1928, and won in 1934, it should adjusted to those years — Preceding unsigned comment added by 74.12.89.236 (talk) 00:57, 30 August 2018 (UTC)

Ready or not for a GA nomination?

Starting review of whether this article can be improved before submitting a Good Article nomination. All help welcome. Ordering of sections will be modeled on the GA vitamins C and folate. David notMD (talk) 09:53, 17 December 2019 (UTC)

Several paragraphs are without references. Existing refs may be suitable, need to be reviewed before being used elsewhere. David notMD (talk) 01:02, 22 December 2019 (UTC)

Intending to submit GA nomination on Jan 2nd. All article improvements before and after that date are welcome. Ideally, article will be stable again (not under constant revision) by the time a reviewer agrees to start the process. David notMD (talk) 22:27, 22 December 2019 (UTC)

Nominated January 3rd. David notMD (talk) 11:05, 3 January 2020 (UTC)

Jan 6: reviewing all refs prior to Good Article review process. David notMD (talk) 12:02, 6 January 2020 (UTC)

Added a Pregnancy and lactation subsection to Deficiency section and added a Society and culture section after History. David notMD (talk) 12:07, 11 January 2020 (UTC)

GA Review

This review is transcluded from Talk:Vitamin B12/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: HaEr48 (talk · contribs) 01:49, 11 April 2020 (UTC)

Will review this. HaEr48 (talk) 01:49, 11 April 2020 (UTC)

This is a decently written article, well-referenced and verifiable for the most part, properly structured, broadly covering major aspects, and no unnecessary detail. No neutrality, copyvio, or WP:OR issue as far as I can tell. Images are appropriately licensed. I think the main challenges are readability for a broad audience ( a common problem for technical articles like this) and partial lack of references in some sections, but I believe nothing that can't be ironed out in review. Here are my more specific suggestions, which I hope would help:

• "The vitamin exists as a family of vitamers defined as a number of chemical compounds having a similar molecular structure, each of which shows vitamin activity in a vitamin-deficient biological system". Suggest starting with "The vitamin is not a single compound, but rather .." For a general reader like me it's not obvious that this is implied by the sentence, I have to click things like vitamer in order to find out. Probably even mention that their difference is due to one single group.
• Similarly in the lead paragraph: "It consists of a class of chemically related compounds (vitamers), all of which show physiological activity". I suggest something like "It is not a single compound but a group of four vitamers, compounds which are chemically related and show similar physiological activity." Also "consists of" can be ambiguous in the sense of "protein consists of amino acids" which I realize is not the case here.
• Any reference for the first paragraph of "Definition"?
• vitamin activity in a vitamin-deficient biological system: Any link for "vitamin activity", or can we explain briefly just what kind of activity we're talking about?
• In deficiency, where the increased risk for vegetarians, consider mentioning how vegetarians are different from the previously mentioned vegans (this is not always obvious for people)
• "B12 is a co-substrate of various cell reactions involved in methylation synthesis of nucleic acid and neurotransmitters. Synthesis of the trimonoamine neurotransmitters can enhance the effects of a traditional antidepressant" Suggest connecting the two sentences with "including" so that the relationship between these two facts are clear (if they're indeed related)
• Is the passage about homocysteine related to the first two sentences of that paragraph? If yes, suggest explaining how they're related. If not, suggest rewording to make it clear that they're not.
• "As during pregnancy, what the nursing mother consumes is more important than her liver tissue stores, as it is recently absorbed vitamin content that more effectively reaches breast milk": Suggest merging with the sentence for pregnancy to avoid near duplication.
• Prolonged exclusive breastfeeding is a strong indicator : "Prolonged" sounds relative, is there a guidance on how long is considered high-risk?
• The "Deficiency" section seems underlinked, given that there's a lot of technical terms there. Can you find out more links that can be added?
• Severe vitamin B12 deficiency is corrected with frequent intramuscular injections of large doses of the vitamin, followed by maintenance doses at longer intervals : How often is "frequent" and "at longer intervals". I know practices will vary, but it would help to know if we're talking about something like every day, every week or every month.
• AI and UL defined the same as in the United States: grammar
• The original deadline to be in compliance: compliance for using 2.4μg, or compliance for including vitamin B12 at all?
• Absorption is promoted by intrinsic factor. Any reason why not "factors" (plural)?
• Link "post-prandial"?
• Can something be linked for "foregut fermenters" , "first-passage feces", "second-passage feces" (or portions of them, or add brief gloss/description if link is not available)
• "Fortified foods" can we add how the fortification is made? From plants, animals, or artificial?
• Consider merging "Fortified foods" and "Supplements" because it seems they're related, and each is not that long
• "The four vitamers of B12 are all deeply red-colored" How does this reconcile with " Pure cyanocobalamin possesses the deep pink color "
• These are converted to the other methylcobalamin form as needed: What does "other" signify here? Isn't there only one methylcobalamin form?
• the human body has the ability (except in rare cases) to convert any form of B12 to an active form: Does this include pseudovitamin-B12?
• Add citations for the specific facts mentioned in vitamers bullet points?
• The biochemistry section contains many specific facts, I think more references are needed.
• "Three types of enzyme:" incomplete sentence?
• "show the most direct and characteristic secondary effects" link "secondary effects" or reword to be easier to understand?
• Suggest clarifying the "enzyme function" section here and there because it is quite hard to follow right now.
• "There is no "gold standard" test for B12 deficiency because as a B12 deficiency occurs…" This and the following passage seems to belong to the deficiency section rather than in biochemistry? (e.g. it is related to deficiency in general as opposed to this specific biochemical function)
• link/explain "reaction type 1" when first mentioned ? Or does it refer to the three types of enzyme mentioned above?
• the X group is -COSCoA: The X group of what?
• may overwhelm the complex R-factor and IGF-factor dependent absorption: Link or add long form of IGF? Or is it a typo for IF?
• Adsorption: The adsorption through intrinsic factor is discussed in detail, can we also explain how diffusion of B12 works?
• The third para of Adsorption needs references.
• methyl-labelled: would a link to isotopic labeling be appropriate here?
• (the French Sanofi-Aventis and three Chinese companies): Any reason why the Chinese companies aren't named while the French one is? Any indication which one(s) are the bigger producers?

I hope my review is useful. Great job on this article. HaEr48 (talk) 23:53, 11 April 2020 (UTC)

Oy. Will get on all this. David notMD (talk) 01:14, 12 April 2020 (UTC)

Started changes. Will copy groups of the above bullets and paste in with explanations of how addressed, in italics. David notMD (talk) 22:16, 12 April 2020 (UTC)

Numbered the bulleted list of comments and so far addressed numbers 13-20 and 30-35. For each, response to the comment is in italics, first word or words in bold so as easier to see. Will continue to address comments in groups. David notMD (talk) 14:22, 13 April 2020 (UTC)

• 1. "The vitamin exists as a family of vitamers defined as a number of chemical compounds having a similar molecular structure, each of which shows vitamin activity in a vitamin-deficient biological system". Suggest starting with "The vitamin is not a single compound, but rather .." For a general reader like me it's not obvious that this is implied by the sentence, I have to click things like vitamer in order to find out. Probably even mention that their difference is due to one single group. Addressed by rewording of first paragraph of Definition section.
• 2. Similarly in the lead paragraph: "It consists of a class of chemically related compounds (vitamers), all of which show physiological activity". I suggest something like "It is not a single compound but a group of four vitamers, compounds which are chemically related and show similar physiological activity." Also "consists of" can be ambiguous in the sense of "protein consists of amino acids" which I realize is not the case here. Second paragraph of lead revised to be more clear about "vitamers" and how the four now-named forms relate to each other.
• 3. Any reference for the first paragraph of "Definition"? References added and wording revised.
• 4. vitamin activity in a vitamin-deficient biological system: Any link for "vitamin activity", or can we explain briefly just what kind of activity we're talking about? Defined by using a sentence and ref from the Biochemistry section.
• 5. In deficiency, where the increased risk for vegetarians, consider mentioning how vegetarians are different from the previously mentioned vegans (this is not always obvious for people). Deficiency section clearer on vegetarian vs. vegan. Also, older people having lower stomach acid had been mentioned in first and third paragraphs, so cleaned up, with a link to achlorhydria added. Created Diagnosis subsection.
• 6. "B12 is a co-substrate of various cell reactions involved in methylation synthesis of nucleic acid and neurotransmitters. Synthesis of the trimonoamine neurotransmitters can enhance the effects of a traditional antidepressant" Suggest connecting the two sentences with "including" so that the relationship between these two facts are clear (if they're indeed related). Resolved instead by deleting both sentences. The references for both were individual clinical trials, hence not WP:MEDRS. In addition, the content (B12 and depression) needs to be a separate subsection.
• 7. Is the passage about homocysteine related to the first two sentences of that paragraph? If yes, suggest explaining how they're related. If not, suggest rewording to make it clear that they're not. Created a diagnosis subsection.

  Thank you, it is clearer now. Just a small comment, the paragraph looks weird starting with just a quoted sentence without explanation: "At present, no ‘gold standard’ test exists for the diagnosis of vitamin B12 deficiency.". Suggest either (1) adding "According to ...", (2) Partially rewording so that only part of the sentence is in quotation marks. HaEr48 (talk) 13:01, 21 April 2020 (UTC) Framed first sentence of Deficiency with "According to..." Also, added the rest of the quoted sentence.

• 8. "As during pregnancy, what the nursing mother consumes is more important than her liver tissue stores, as it is recently absorbed vitamin content that more effectively reaches breast milk": Suggest merging with the sentence for pregnancy to avoid near duplication. Removed the words "As during pregnancy" but left rest of sentence. It is important to have the two separate paragraphs to address pregnancy and breastfeeding, as each are risks to the fetus and infant, respectively.
• 9. Prolonged exclusive breastfeeding is a strong indicator : "Prolonged" sounds relative, is there a guidance on how long is considered high-risk? Replaced with after six months, and added a mention that risk applies to near-exclusive breastfeeding when the foods been fed are not good sources of B12.
• 10. The "Deficiency" section seems underlinked, given that there's a lot of technical terms there. Can you find out more links that can be added? More Wikilinks added and text shortened because there was redundancy about B12 and homocysteine, methionine and neurotransmitters.
• 11. Severe vitamin B12 deficiency is corrected with frequent intramuscular injections of large doses of the vitamin, followed by maintenance doses at longer intervals : How often is "frequent" and "at longer intervals". I know practices will vary, but it would help to know if we're talking about something like every day, every week or every month. Specifics added, along with new ref.
• 13. AI and UL defined the same as in the United States: grammar Fixed
• 14. The original deadline to be in compliance: compliance for using 2.4μg, or compliance for including vitamin B12 at all? Fixed
• 15. Absorption is promoted by intrinsic factor. Any reason why not "factors" (plural)? No change. From Intrinsic factor, singular applies.
• 16. Link "post-prandial"? Done
• 17. Can something be linked for "foregut fermenters" , "first-passage feces", "second-passage feces" (or portions of them, or add brief gloss/description if link is not available). Better explanation of how foregut and hindgut fermenters getting B12 from bacterial fermentation of plant food; the digestive system bacteria are making the vitamin.
• 18. "Fortified foods" can we add how the fortification is made? From plants, animals, or artificial? Sentence added to state that it is microbial fermentation cyanocobalamin

  Thank you. Add source for the new sentence? HaEr48 (talk) 13:01, 21 April 2020 (UTC) Sentence improved and ref added.

• 19. Consider merging "Fortified foods" and "Supplements" because it seems they're related, and each is not that long. Prefer not. Fortification uses cyanocobalamin, but supplementation offers other vitamers. Also, fortification limited to range of natural foods, whereas supplementation can and often extends to mega-dosing, i.e., amounts in great excess compared to recommended intakes. Added mention and ref that some countries require fortification.
• 20. "The four vitamers of B12 are all deeply red-colored" How does this reconcile with " Pure cyanocobalamin possesses the deep pink color " Removed sentence mentioning deep pink.
• 21. These are converted to the other methylcobalamin form as needed: What does "other" signify here? Isn't there only one methylcobalamin form? Removed "other".
• 22. the human body has the ability (except in rare cases) to convert any form of B12 to an active form: Does this include pseudovitamin-B12? Deleted/replaced "any form" to exclude thinking that pseudovitamin B12 was included. Another editor added content about assay methods for pseudovitamin B12.
• 23. Add citations for the specific facts mentioned in vitamers bullet points? Rewritten and references added.

  " Under normal conditions, oral consumption of any of the vitamers disassociates to cobalamin, and then combined with a methyl ligand in the cytosol or an adenosyl ligand in mitochondria" Suggest adding that these results in the two active forms (MeB12 and adoB12), because it is not necessarily obvious to the general reader. HaEr48 (talk) 13:01, 21 April 2020 (UTC) Agreed, and done.

• 24. The biochemistry section contains many specific facts, I think more references are needed.
• 25. "Three types of enzyme:" incomplete sentence? Converted to a complete sentence
• 26. "show the most direct and characteristic secondary effects" link "secondary effects" or reword to be easier to understand? Deleted Enzyme Function subsection because it was unreferenced garbage.
• 27. Suggest clarifying the "enzyme function" section here and there because it is quite hard to follow right now. Deleted Enzyme Function subsection because it was unreferenced garbage.
• 28. "There is no "gold standard" test for B12 deficiency because as a B12 deficiency occurs…" This and the following passage seems to belong to the deficiency section rather than in biochemistry? (e.g. it is related to deficiency in general as opposed to this specific biochemical function) Moved to a Diagnosis subsection under Deficiency.
• 29. link/explain "reaction type 1" when first mentioned ? Or does it refer to the three types of enzyme mentioned above?
• 30. the X group is -COSCoA: The X group of what? Revised first sentence of the explanation of what Methylmalonyl Coenzyme A mutase does, added ref from that article

  Thanks. Can you add reference also to the last sentence of the Methylmalonyl Coenzyme A mutase bullet point? HaEr48 (talk) 13:01, 21 April 2020 (UTC) Ref added.

• 31. may overwhelm the complex R-factor and IGF-factor dependent absorption: Link or add long form of IGF? Or is it a typo for IF? "IGF" was a typo. The sentence reworded to "The passive diffusion process of B₁₂ absorption may overwhelm the R-protein and IF mediated absorption when oral doses..."
• 32. Absorption: The absorption through intrinsic factor is discussed in detail, can we also explain how diffusion of B12 works? Described as "passive." First and last paragraphs modified to state that passive is a small portion of total absorption of B12 from foods, but becomes a large portion of total with mega-dosing.

  I added "by which most food consumption of the vitamin is adsorbed" to the first sentence that describe the first process, so that it's clear from the get go. See what you think and correct me if I'm wrong Yes, I agree that is an improvement.

• 33. The third para of Absorption needs references. Existing ref and new ref for third paragraph
• 34. methyl-labelled: would a link to isotopic labeling be appropriate here? Addressed by another editor.
• 35. (the French Sanofi-Aventis and three Chinese companies): Any reason why the Chinese companies aren't named while the French one is? Any indication which one(s) are the bigger producers? Chose to delete name of French company rather than add names of three Chinese companies listed in the reference, mostly because this is old (2008) information. Also removed the corporate mention of Aventis and Sanofi in the preceding paragraph.

Will continue to address in groups. David notMD (talk) 14:22, 13 April 2020 (UTC)

*34 made the suggested link and added ¹³C to indicate type of label used. Michael D. Turnbull (talk) 13:27, 14 April 2020 (UTC)

Addressed 8-11 and 21,22. There is no #12; that was a misnumbering when I copied and numbered the list. Still to do: 1-7, 23-29. David notMD (talk) 13:37, 15 April 2020 (UTC)

Addressed 5-7 (leaves 1-4, 23-29). With the establishment of a Diagnosis subsection, content Biochemistry moved to Diagnosis and references added. David notMD (talk) 11:09, 16 April 2020 (UTC)

Addressed 1-4 (leaves 23-29) David notMD (talk) 13:59, 18 April 2020 (UTC)

Addressed 23-25, 28. Leaves 26 and 27. On close read, the entire Enzyme Function section is a farce. Copying it to my sandbox to fix, then will past back in, That will address 26 & 27. David notMD (talk) 00:08, 21 April 2020 (UTC)

@David notMD: Thank you. Your changes look good in general, though I added some small follow up comments above, please take a look. Also, I realized I made a lot of comments, please don't take this to mean that I don't like the article (it's actually the opposite), it's just I believe these will improve the article further. Let me know once you pasted in your update and what you think of my follow up comments above. HaEr48 (talk) 13:01, 21 April 2020 (UTC)

Whatever does not kill this GA review makes it stronger. I deleted the Enzyme Function subsection because it was unreferenced garbage. If there is anything worth salvaging I will revise, reference, and add to Medical uses. Carrying on. David notMD (talk) 21:02, 21 April 2020 (UTC)

I believe I had addressed all of the initial and to-date follow-up comments. David notMD (talk) 10:37, 23 April 2020 (UTC)

@David notMD: Thank you so much for your updates. I think those address my feedback about clarity and referencing. I am happy to pass this article as GA. Keep up your great work! HaEr48 (talk) 12:26, 23 April 2020 (UTC)

Added Gastric bypass surgery section

Gastric bypass surgery, specifically the Roux-en-Y bypass procedure, is a known cause of B12 deficiency which can be prevented by injection or high dose oral. David notMD (talk) 07:19, 21 April 2020 (UTC)

@David notMD: Should it be under "Deficiency" ? Similar to how pregnancy is under that subsection. HaEr48 (talk) 12:57, 21 April 2020 (UTC)

I agree. Moved it. David notMD (talk) 13:15, 21 April 2020 (UTC)

Vegan advocacy groups

Pretty sure that ideological groups fail WP:MEDRS. Medical and governing bodies do discuss vegan nutrition and they should be cited instead. Harizotoh9 (talk) 08:23, 20 April 2020 (UTC)

The fact that vegan advocacy groups (no longer named in text of article) recommend fortified foods is not controversial, and in my opinion is information worth referencing. I will, however, find and add government and/or NGO references to the statement. David notMD (talk) 14:59, 20 April 2020 (UTC)

The issue is that vegan advocacy groups fail WP:MEDRS. Thus they can't be used as sources and anything they recommend is irrelevant. The section on fortified foods shouldn't even open with vegans since the vast majority of people who consume fortified foods are omnivores of the general public. Harizotoh9 (talk) 08:06, 21 April 2020 (UTC)

The vast majority of people who consume fortified foods are not selecting those foods because of the B12 content. For cereals, its vitamins. For non-dairy 'milk,' vitamin D. People who choose a veganism diet are exactly the people who are instructed to get B12 from fortified foods or dietary supplements. For this reason, I consider B12 guidance from vegan advocacy groups valid. Citing that information does not bleed over into supporting why people choose a vegan diet, or any other platform of those advocacy groups. This article is in the middle of a Goo Article review. I suggest you bring this discussion to the attention of the reviewer, as we do not have enough participants at the moment to reach a consensus. David notMD (talk) 08:33, 21 April 2020 (UTC)

My position is that WP:MEDRS applies to science evidence. David notMD (talk) 01:08, 23 April 2020 (UTC)

Did you know nomination

The following is an archived discussion of the DYK nomination of the article below. Please do not modify this page. Subsequent comments should be made on the appropriate discussion page (such as this nomination's talk page, the article's talk page or Wikipedia talk:Did you know), unless there is consensus to re-open the discussion at this page. No further edits should be made to this page.

The result was: promoted by The Squirrel Conspiracy (talk) 02:23, 13 May 2020 (UTC)

(

• Comment or view
• Article history

)

• ... that five people received Nobel Prizes for direct and indirect studies of vitamin B12? Source: "Five Nobel Prizes have been awarded for direct and indirect studies of vitamin B12: George Whipple, George Minot and William Murphy (1934), Alexander R. Todd (1957), and Dorothy Hodgkin (1964). ref #112 The Nobel Prize and the discovery of vitamins(

• Reviewed: Alexandrea Owens

Improved to Good Article status by David notMD (talk). Self-nominated at 01:42, 24 April 2020 (UTC).

General: Article is new enough and long enough
New enough: Long enough:

Policy: Article is sourced, neutral, and free of copyright problems
Adequate sourcing: Neutral: Free of copyright violations, plagiarism, and close paraphrasing:

Hook: Hook has been verified by provided inline citation
Cited: Interesting:

QPQ: Done.

Overall: epicgenius (talk) 13:29, 25 April 2020 (UTC)

Human small intestine?

Text and a ref (Albert 1980) https://www.cmcwtrl.in/publications/4-1980-Nature.pdf were added as claim that bacterial presence in small intestine of humans may result in absorbed B12. Is this strong enough evidence? David notMD (talk) 11:17, 24 August 2020 (UTC)

In addition to this being a primary source, the assumption we would need to make to accept this as written is a problem.

The article discusses possible differences in a localized population, theorizing that differences in gut microflora may be at work. This is in 1980. 40 years later, contrary to all other sources we have, an editor on Wikipedia essentially is telling us that all of the literature published since is wrong. - SummerPhD^v2.0 18:02, 24 August 2020 (UTC)

I agree with you. I just did not want to be hasty. Furthermore article PMID 15539065 states in its abstract that small intestine bacterial overgrowth would, if anything, reduce absorption of dietary B12 rather than serve as an absorbable source of bacteria-synthesized B12. David notMD (talk) 19:22, 24 August 2020 (UTC)

Sentence and Albert 1980 ref deleted. David notMD (talk) 02:49, 25 August 2020 (UTC)

No need to wait on this one. We can find any number of studies that found a swallow in San Juan Capistrano in early February. Nevertheless you were right to question and ax this one. - SummerPhD^v2.0 03:07, 25 August 2020 (UTC)

I took a look at the citations for the Nature article via Google Scholar. There are 185 of them. Of the ones I looked at, they seemed to be interpreting the article to say that the B12 produced by the gut microbiota is unlikely to be available directly to the host (it goes out in the faeces) or if available, still makes only a small contribution so that in vegetarians, for example, it can't prevent B12 stores becoming depleted. Hence I think that here on WP we are justified in ignoring it as being of only minor relevance. Michael D. Turnbull (talk) 11:43, 25 August 2020 (UTC)

´See also´s ´been removed

These notes with links to ´See also´ just have been removed. Without notification.

• Spirulina (dietary supplement), natural (nature) product of algas, including B12
  
• Mineral (nutrient)
  
• Vitamin deficiency
  
• Micronutrient deficiency
  

In my opinion those themes are very direct related to Vitamin B12. I had to do hard works, to just find it for my current needs.
To save time for other researchers and being looking for and finding it fast, it would be very helpful, at least at ´See also´.
But if wikipedia does not have this in mind or at all in interesst, then wiipedia for me is very, very wrong and not to use anymore, for most of nothing. Sorry. This is not to work with.
Further links:

• Human nutrition
  
• Micronutrient
  

--Visionhelp (talk) 04:27, 9 April 2021 (UTC)

• My opinions: Spirulina is not a valid 'See also' for vitamin B12 because at that article it clearly states that spirulina is not a source of B12. A see also to Mineral (nutrient) does not apply because B12 is a vitamin. 'See also' for Micronutrient, Micronutrient deficiency and Human nutrition are not useful because no information is present there that compliments the B12 article. The first two are actually Start-class articles that have no mention of B12. David notMD (talk) 22:30, 9 April 2021 (UTC)
• @Visionhelp: The only relevancy-compliant links are about Vitamin deficiency and Micronutrient deficiency The rest isn't that good. Instead of populating «See also» I suggest to H:WIKILINK the article's text by said two topics. I also see that David notMD already added more narrow link on Vitamins' deficiency. This is not a good step IMO as this section's content was disputed. --AXONOV (talk) ⚑ 15:20, 15 April 2021 (UTC)

Please, what do You mean with "This is not a good step IMO as this section's content was disputed." ? (To have to face like this now this talk being seperated, I have to face as respectless to my works.)
"pseudovitamin B12": what is a pseudovitamin, please ? (No wikipedia article about ? No source of this saying ?)
But currently I am figuring out the existencial and essential meaning the human nutrients, for example Magnesium, Borum, Vitamin B12, being in the bones as long no deficiency is happening. Else the body-need is going to take it off out of the bones.
And this very connection and happening for me is just going to be the most important to know and to understand, for the very own health, of everybody. This in my understanding does need a presentation of this very clear, and at very first, where is represented vitamins and minerals, which are essentially and existencially in the bones of a human. As next the connections and interactions to other vitamins and minerals, but easy understandable and easy to see, not first to search for (if (and when) knowing, what) for everybody, and not scientifically. (Just saying, please. Thank You.)
Visionhelp (talk) 12:29, 21 April 2021 (UTC)

The term "pseudovitamin" appears to have only been used to describe vitamin B12-like compounds that do not have vitamin B12 function. Thus, there does not seem to be a need for an article on pseudovitamins when the section within the B12 article is sufficient. David notMD (talk) 12:47, 21 April 2021 (UTC)

(I really do not like this talk style. You take my criticism to a (my opinion) missing wikipedia article personally and able as to decide alone such, "does not seem". Sorry. And I have to apologize for my claim, in Spirulina is B12. I myself just cannot understand, where I could have it from, or if it ´just´ was a ´simple´ mistake of me. Sorry.)
And I have to admit, I found the source there (https://en.wikipedia.org/wiki/Spirulina_(dietary_supplement)#Vitamin_B12) with this saying: (#cite_note-20)
" "Pseudovitamin B12 Is the Predominant Cobamide of an Algal Health Food, Spirulina Tablets". Journal of Agricultural and Food Chemistry"
But my very opinion is, I do want to know, what is this pseudovitamin B12, for to be able to decide myself, for: what to have or may to think of it.
And Cobamide is a saying, but I cannot find a translation to german, and not the english Cobamide as german article.
Visionhelp (talk) 13:24, 21 April 2021 (UTC)

Clarify definition of vitamin activity?

David notMD, in the above GA process, you said you Defined [the term "vitamin activity"] by using a sentence and ref from the Biochemistry section. As a layperson reading the article (Special:Permalink/1045741551), I can't find where this definition is. Is it this following sentence?

The vitamin activity is as a coenzyme, meaning that its presence is required for some enzyme-catalyzed reactions.

If I didn't know that there's meant to be a definition of the term in the article, I doubt I'd ever understand this as a definition of "vitamin activity"; rather, I would see it as a statement about the vitamin's "activity" that requires the reader to understand the term "vitamin activity" already. Could it be clarified? For example, merging it with the preceding sentence:

These chemical compounds, termed vitamers, have a similar molecular structure, each of which, when in a vitamin-deficient biological system, shows vitamin activity, meaning that it acts as a coenzyme, which means that its presence is required for some enzyme-catalyzed reactions.

(I suspect, however, that my proposed text is inaccurate, as I don't really understand what the article is trying to say.)

—2d37 (talk) 02:33, 26 September 2021 (UTC)

As a layperson, and not scientifically, I take the words "vitamin activity" as what the words say; what (the / a) vitamin does, at all.
Therefor, in my point of view, it is necessary, that (and THE vitamins and minerals, the need of a body of nutrients) they are working depending on each other; and more then just each other only, because there will be still some more requirements, to have it working at all at the end.

Further, in my point of view, I do recognize, this does not seem to be a topic still at all.

´vitamin activity´ does meet these points ´NEARBY´ a little into this direction.

But, if just disturbing, then sorry, please.

(The link to ´Definition´ https://en.wikipedia.org/wiki/Vitamin_B12#Definition)

Visionhelp (talk) 10:10, 27 September 2021 (UTC)

"Plants"

For openers, please stop calling things that are not plants "plant sources". Thanks.

The source you have added is clear that non-animal sources -- along with the artificially fortified foods and supplements that all vegans should be using -- may contribute modestly to the prevention of vitamin B12 deficiency. The source does not say that, gee, if we had better studies and if more people knew about them we would all be able to live happy, healthy lives based on a few algae, fungi and vegetables processed with fungi and bacteria. The source says, "Together with B-vitamin fortified food and supplements, these foods may contribute, though modestly, to prevent vitamin B12 deficiency in individuals consuming vegetarian diets." - SummerPhD^v2.0 13:35, 18 April 2017 (UTC)

Fair enough that 'Plant sources' is changed to 'Plant and mushroom sources'. The cited source speaks of "seaweed" in general, not only one type of seaweed. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3062981/ "seaweeds contain considerable amounts of vitamin B12" "In conclusion, several plant-origin foods including seaweed, soybean-fermented foods, and kimchi, may contribute significantly to good vitamin B12 status". In addition, this citation could be added https://www.ncbi.nlm.nih.gov/pubmed/10794633 "green (Enteromorpha sp.) and purple (Porphyra sp.) lavers (nori) [...] are the most excellent source of vitamin B(12) among edible seaweeds". Lavers, Nori, and Seaweed are often interchangeable terms. Please do not revert multiple unrelated entries due to laziness or frustration in the future. Cyrus Freedman (talk) 15:45, 18 April 2017 (UTC)

Please do not accuse me of laziness or assume I am frustrated. Instead, realize that your changes have been challenged repeatedly and slow down. Taking one issue at a time, explain your edits (or, heck, discuss them ahead of time) and allow a reasonable amount of time for responses.

Let's try this issue first: "Plants". Seaweed is an algae, it is neither a plant nor a "mushroom" (fungus). Fermented vegetables are also not plants, they are the result of fungi and/or bacteria partially digesting plants. Fermented vegetables are "plants" to the same degree that bread and beer are.

What is gained by grouping together foods from various kingdoms and grouping them together under some contrived moniker via inclusion? The sources make it clear that animal-based foods (meats, eggs, dairy, etc.) are the main source of B12 for humans. Everything else falls into three broad categories. For vegans, the primary sources are artificially fortified foods and supplements. Finally, a small number of non-animal based foods may contribute modestly to preventing vitamin B12 deficiency in vegans. - SummerPhD^v2.0 19:09, 18 April 2017 (UTC)

There is a confusion for me around vegan sources. The first paragraph says that there are no vegan sources of B12. Then a bit further down, we talk about fermented food and algae. Isn't there a contradiction here? Brainstudent87 (talk) 21:09, 3 September 2018 (UTC)

Most of the apparent B12 sources mentioned under "Plants and algae" are seriously questioned in "B12 in Plant Foods" here: https://veganhealth.org/vitamin-b12-plant-foods/ I'm not qualified to judge its correctness, but it contains enough references for others to do so. If it is correct, then most of the 'sources' mentioned in this section are dangerously misleading for vegans. J77h (talk) 06:41, 30 December 2019 (UTC)

The way this section is worded is misleading. The test done in the studies on vitamin B12 content in seaweed does not necessarily distinguish between vitamin B12 and psuedovitamin B12 (analogue B12). Algea sources tested for vitamin B12 have been shown to contain large amounts of psuedovitamin B12. This is a health problem as pseudovitamin B12 binds to the same cell transporters as real vitamin B12, thus blocking the uptake of vitamin B12 in the cells. Also the wording on fermented foods reads as if many fermented foods contain B12, the science linked does however state: "The Vitamin B12 contents of soybeans are low or undetectable. However, a fermented soybean-based food called tempe contains a considerable amount of Vitamin B12 (0.7–8.0 μg/100 g) [40]. Bacterial contamination during tempe production may contribute to the increased Vitamin B12 content of tempe [41]. Other fermented soybean products contain minute amounts of Vitamin B12 [42,43]." So the detected vitamin B12 in the tempeh tested in the study is due to a bacterial contamination and not a product of the fermentation.

The wording on the page makes it looks like people can eat many types of seaweed and/or fermented soy products and get enough vitamin B12 in their diet, this is not only factually incorrect, but also a dangerous claim. — Preceding unsigned comment added by 2001:4647:C8E3:0:C5A4:E660:C895:DFA2 (talk) 00:29, 1 November 2018 (UTC)

https://www.b12-vitamin.com/analogs/ — Preceding unsigned comment added by 2001:4647:C8E3:0:64F7:A007:FA69:38C1 (talk) 12:52, 1 November 2018 (UTC)

The Academy of Nutrition and Dietetics considers plant and algae sources "unreliable". They might consider this and it might even be true but is there some organisation not sponsored by e.g. McDonald's that also says so? I tend to believe it more based on what's claimed here in talk than based on this source.NicoLaan (talk) 08:32, 20 January 2022 (UTC)

The Academy of Nutrition and Dietetics's article itself references this article[2] from an American registered dietitian concerned about neglected B12 deficiencies in vegan diets. "Vitamin B12-Containing Plant Food Sources for Vegetarians"[3] discusses sources of naturally occurring B12 including bioavailability to plausibly reduce incidence of deficiencies suitable for most vegetarian diets around the globe, including vegan ones. I suspect that the prevalence of fortified foods in the general population will more pragmatically reduce deficiencies than hoping groups at risk eat enough purple laver every day provided fortified foods are widely distributed. In contrast, overconsumption[4] of B12 does not appear to be a significant issue.

As for "plant", I would think most readers interested in this section are here to learn about B12 in terms of some kind of vegetarian diet where the use of the word plant is both historical and colloquial even if not technically correct in modern scientific classification. Slythfox (talk) 06:07, 14 February 2022 (UTC)

Cobalamin in plants

Can someone add something about how plants obtain cobalamin? They obviously need it, just as animals do, but they don't eat (or most of them don't). The only thing I have found is this which says that B12 "kann in Spuren auch in Pflanzen, die mit Bakterien in Symbiose leben (z.B. Leguminosen), vorkommen" ("can occur in traces quantity also in plants which live in symbiosis with bacteria (e.g. legumes)"). Eric Kvaalen (talk) 16:10, 21 December 2018 (UTC)

That's basically small traces of cobalamin produced by plants interacting with microbes found and bred in animal dung that basically works to fertilize the plant. Hence, "artificial" cobalamin is usually made by means of "potting soil", which is basically earth mixed with dung to grow plants in. Still, the trace amounts of cobalamin produced that way are:

• a.) very, very small and thus not suitable to fix human dietary cobalamin needs (such as from a vegan diet resulting in cobalamine deficiency), and
• b.) are hardly metabolizable by the human body, unlike cobalamin produced in animal products such as meat, fish, milk, and eggs. It's basically identical to the pseudo-cobalamin found in algae that is not suitable to fix human dietary needs.

b.) basically means that even *IF* "artificial" cobalamin derived from growing plants in dung soil could be produced at amounts similar to the amounts found in animal-derived foods and used for human diet, the human body fed such would still suffer cobalamin deficiency because artificial cobalamine is hardly metabolizable and mostly just excreted rather than exploited to feed the body. --46.93.159.143 (talk) 22:30, 10 September 2019 (UTC)

Vascular plants do not require B₁₂, and they use different enzymes and genetic mechanisms to synthesize DNA without B₁₂. All animal life on earth is dependent on B₁₂ for DNA synthesis and maintenance of nerve tissue which cannot work without B₁₂ (technically all life which has cells which contain mitochondria require B₁₂ for DNA synthesis). Plants which contain B₁₂ obtained it from bacterial sources. See Octoberwoodland (talk) 02:20, 22 September 2019 (UTC)

Thanks, Octoberwoodland. But why do you say that all life which has cells which contain mitochondria require B₁₂, but also that plants don't require it? Plants have mitochondria. Please ping me so I'll see your reply before another two years have passed! Eric Kvaalen (talk) 10:01, 25 December 2021 (UTC)

References

Relevance of File:Витамин В12 100х (3).jpg

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result of this discussion was not to use the image in the article. The onus to achieve consensus for inclusion is on those seeking to include disputed content and no-one apart from the proposer supported this. Mike Turnbull (talk) 14:08, 12 July 2022 (UTC)

---

This file has been added and removed several times in the past few days. It appears to be a micrograph of B12 crystals but I am not convinced it is useful in this article, and in any case should not be in the "deficiency" section. @JukoFF and David notMD: to comment. Mike Turnbull (talk) 22:39, 30 June 2022 (UTC)

Regarding the location in the section you are absolutely right, probably the illustration should be moved to a more appropriate place, if you tell me where it would be more appropriate, I would be grateful to you. But in general, it seems to me to be quite appropriate in the article, as it illustrates the object of the article directly. All other illustrations are either formulas, portraits, or medical preparations. JukoFF (talk) 22:44, 30 June 2022 (UTC)

I have already deleted this twice, and had hoped that JukoFF would refrain from adding it a third time without first gaining a consensus here at the article's Talk page, which is where I had advised JukoFF to take up the debate. To my eye, it is an abstract image that in no way provides useful information to readers of the article. Looing at it, I have no idea which part of the image is B12. The caption "Vitamin B12 is a hundredfold increase." (assumed to be a translation) does not help. David notMD (talk) 00:44, 1 July 2022 (UTC)

In fact, this image is t he only one on the page which, to some extent, shows the object of the article, I think it is difficult to argue with this, because it is obvious and this is a fact. I sent a description of the image. JukoFF (talk) 01:24, 1 July 2022 (UTC)

JukoFF - you and I are in disagreement on the value of the image you added. In addition to Michael D. Turnbull, I am asking Zefr, Smokefoot and Johna188 to share their thoughts on this, as they have edited this article in the past. David notMD (talk) 02:51, 1 July 2022 (UTC)

In the 'Deficiency' section, it's definitely not enlightening. I'm not sure it has a place at all in the article. "To some extent, shows the object of the article", but I think not in a way that is accessible to the general reader. The layman has no reference point for appreciating or understanding the photo. _signed, Willondon (talk) 02:57, 1 July 2022 (UTC)

I appreciate that Willondon removed the image while it is under discussion. To other editors, it can be seen by looking at the version of the article after it was added by JukoFF. David notMD (talk) 10:13, 1 July 2022 (UTC)

The JukoFF image has no value at all. Neither a common user nor an expert would recognize what it is. Zefr (talk) 14:07, 1 July 2022 (UTC)

JukoFF Are you willing to accept that there is a consensus that the image should not be in the article? David notMD (talk) 00:51, 6 July 2022 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Legal status

The infobox claims B12 is a POM in the UK. This seems a strange assertion when supplements can be bought freely in any outlet that sells vitamins. Obviously there are some forms that are POM, but that is true of most countries including the US, where the infobox claims it is OTC. Can an expert editor clarify this? Ef80 (talk) 14:29, 30 October 2022 (UTC)

I am in U.S. Anyone in UK who can follow up on this? David notMD (talk) 15:33, 30 October 2022 (UTC)

I think that the POM refers to the use of injectable B12, which would be the normal treatment for a serious deficiency, see this NHS webpage. There are of course lots of dietary sources of B12 which could otherwise be used. I'm not sure whether simple B12-containing pills can be bought OTC in the UK but I would not be surprised if they could. After all, it is commonly fortified into our cornflakes. Mike Turnbull (talk) 18:28, 30 October 2022 (UTC)

B12 supplements are very widely available in the UK as you'd expect, e.g. https://www.hollandandbarrett.com/shop/product/holland-barrett-timed-release-vitamin-b12-tablets-1000ug-6100269106?skuid=047345. The article seems to be using different criteria for the UK and US. --Ef80 (talk) 15:28, 31 October 2022 (UTC)

NHS-guidelines (and uk docs) seem to have a preference for treating B12-deficiency with intramuscular hydroxycobolamin. Oral cyanocobolamin is available as OTC for self-medication or maintenance therapy. [5] Draken Bowser (talk) 16:53, 31 October 2022 (UTC)