Trust me, it's always a rabbit hole; with claims like "humans used to be entirely, or mostly, vegan and got our vitamin b12 from eating the dirt on root vegetables" or "if we stopped washing our fruits and vegetables we would get enough from the bacteria on the produce"
yeah, I've heard it argued that B12 is produced by a lot of soil bacteria, which would have been sufficient for historic vegans.. but now since plants are washed we don't get B12 (and salmonella!) from plant sources.
As a vegan, I’m not surprised. We all have to get our vitamin b12 from functional food because it would otherwise naturally occur on the foods we eat from bacteria. Our foods are sterile and thus the bacteria never deposit b12 for us. There’s probably much more we don’t know about.
They are completely wrong. There is some b12 generated by our gut bacteria but it is too low in the digestive track to be effectively absorbed. There is a reason vegans eat foods enriched in b vitamins.
I'd have to spend more time than I have hunting the relevant studies down. I don't even pretend to understand most of the fundamental science, but my very cursory studies show that long-term vegan diets are pretty much a terrible idea for humans, despite what vegan advocacy literature proclaims, there are no populations of humans on the planet that go for a lifetime (or generations) on a purely vegan diet. Most of the ones used as examples, have some animal sources in their diet but those sources are not recorded or well understood by outside observers who are also biased by trying to advocate for a particularly philosophical dietary proscription.
Just with respect to the B group vitamins, there's quite a few studies of vegan populations that show a consistent deficit in B12. Depending on the study, vegan populations consistently show (at 70-90% of the studied population) B12 deficits, even while taking supplements. The general conclusion among nutritionists is that it's very very hard for vegans to get enough B12 in their diets no matter what they try. Strangely, these studies never seem to show up in Vegan advocacy circles or support groups, though there is a general awareness that B12 availability is a problem with the diet. More problematic, B12 deficiency (and the related issues below) do not present as immediate health issues, but develop over years and decades - presenting as permanent damage to neurological tissues. People who switch to Vegan diets often don't present with this deficiency for several years as the liver maintains a 3-5 year store of the vitamin.
B12 deficiency can be fatal. B12 deficiency is trivially treated by eating meat - surprisingly little meat too. Similar studies of Vegetarian populations who occasionally eat some animal source, don't show nearly as frequent B12 deficiencies as in Vegan populations.
Identifying B12 deficiency can be difficult as normal assays don't reliably show deficiencies, and initial symptoms looks like anemia, which is also highly prevalent among vegan dieters and may co-present.
Along with B12 deficiency, elevated methylmalonic acid is typical in some majority of the studied vegan populations. Which is used as a secondary signal to confirm B12 deficiency. MMA reacts with B12 to produce coenzyme A (CoA) which is necessary for normal cell function. People with elevated MMA are often diagnosed with methylmalonic acidemia - a group of disorders which are normally only seen in infants with specific genetic conditions relevant to B12 absorption, but present with progressive encephalopathy and hyperammonemia, both can cause death over the long-term.
A majority of vegans can also usually be diagnosed with Hyperhomocysteinemia (which is only ever seen in three population groups, the severely malnourished, the extreme elderly and vegans and is trivially treated with an omnivorous diet). Studies which show cardiovascular issues in Vegans (surprisingly more common than you'd think) attribute them to Hyperhomocysteinemia as Homocysteine prevents proper formation and maintenance of key cardiovascular components like collagen and elastin (also noticeable in Vegan populations as "thin skin" or "premature wrinkling"). It's also linked to Alzheimer's disease and Schizophrenia. The later disease occurs in vegan populations with a startlingly higher frequency than in vegetarian and omnivorous dieter populations.
This is just some of the issues from B12 deficiency, which occurs somewhere between 70-90% of any randomly selected vegan population. So we know that vegans, as a general population, are not able to supply themselves with sufficient B12.
You can probably google for the relevant studies on your own. There's plenty of them around, but I'd urge you to find them in medical journals, not interpreted through vegan advocacy sites which seem to have a habit of ignoring the important health issues and suppressing negative health outcomes from the diet.
I'd urge you to check out amino acids, and fatty acid issues as well, as they are just as common in vegan populations and can be just as health concerning.
Interestingly, almost every single health issue that stems from a vegan diet is trivially treated by just eating a few grams of animal protein sources a week. Eating plant foods or supplements rich in these normally vegan deficient nutrients doesn't mean they're bioavailable, what matters is absorption of the relevant nutrient, which is something that vegan diets are notoriously poor in providing.
>When it's found in "soil", it's due to bacteria and small animals (insects, mites) that are in the soil.
I'm not sure what your point is.
>Any B12(-like) substances that are in plants (e.g., spirulina) are unlikely to be in a form that's bioavailable to human beings.
Yes, this is true.
>Vegans have to take B12 supplements of some sort or eat foods that have been fortified with B12. That's just a fact.
Modern vegans do need to take supplements, yes. The question is whether vegans in the ancestral environment would have gotten sufficient B12 from eating unwashed vegetables and roots. As far as I know, research is lacking on that point, but it is plausible.
You quote a fast food company blog? I'll quote the Vegan Society:
> Claimed sources of B12 that have been shown through direct studies of vegans to be inadequate include human gut bacteria, spirulina, dried nori, barley grass and most other seaweeds. Several studies of raw food vegans have shown that raw food offers no special protection.
> Reports that B12 has been measured in a food are not enough to qualify that food as a reliable B12 source. It is difficult to distinguish true B12 from analogues that can disrupt B12 metabolism. Even if true B12 is present in a food, it may be rendered ineffective if analogues are present in comparable amounts to the true B12. There is only one reliable test for a B12 source - does it consistently prevent and correct deficiency? Anyone proposing a particular food as a B12 source should be challenged to present such evidence.
And also wikipedia which is more reliable and is not trying to sell you anything:
The Academy of Nutrition and Dietetics considers plant and algae sources "unreliable", stating that vegans should turn to fortified foods and supplements instead.[32]
Cite your claims. There are plenty of vegans who are very much alive, and most (but not all) research sugests that well planned vegan diets can be healthy for all life stages.
The most important deficiency in a vegan diet is vitamin B12, but that cannot be produced by any animals (or plants) [0]. Commerically the majority of it is made via bacterial fermentation.
This is incorrect. B12 is made from bacteria widespread in the “wild environment “, but almost completely washed it of the modern diet. The only reason non-vegans don’t typically have to worry about B12 is that cyanocobalamin or other B12s are added into common foods. There’s an argument that cyanocobalamin is bad for you though as your liver creates cyanide in processing it for use in your body. Here’s the quote from the article.
“””
One of the most well-known challenges for vegans is getting enough vitamin B12, which is only found in animal products like eggs and meat.
“””
We used to get B12 from bacteria in the soil, but these days we clean our food immaculately, and we're also ruining our soil. My understanding is that B12 deficiency is a potential problem for everyone; vegan diets are just under more scrutiny. Also, the whole notion of "supplements" is not very useful; it's all just food. I don't know how B12 is produced, but if they're growing it by culturing the same bacteria we used to get B12 from, we have only industrialized the same symbiotic relationship we already had with certain microbes.
Fun fact, animals don't produce B12. Historically meat contained B12 because animals got it from drinking water and eating food that had the microorganisms which do produce it, but in contemporary industrial scale agriculture, where animals are drinking chlorinated water piped into their pen, eating grains from a trough and being given antibiotics, they no longer get it from microorganisms which would have been in their natural environment.
The people running hog confinement operations, cattle feedlots or chicken warehouses give the animals B-vitamin fortified food to make up for the deficiency.
So vegans should take a B vitamin directly, but it's the same B vitamin being given to the animals for it to end up in meat.
My experience is that they eat a lot of potato chips and biscuits. Where do you get your vitamin b12 from?
Regardless, the rest of my comment points out why the person I was replying to is wrong. Even your comment points it out. All you need to do to be a vegan is not eat animal products. This means you can avoid all of the foods that are good for your biome. That was the entire point of the quote from the article that was completely missed by the op.
In addition, not all vegetables are equal with regards to bacteria.
Livestock is given B12 supplements. B12 only occurs naturally in soil, where the concentrations are too low for even animals to bind. Prehistoric humans probably ate more dirt and had enough of it.
Please check your sources. Such advice can be, and in fact is, dangerous to vegans.
Legumes or sprouts are not an adequate source of B12 and neither are other plant sources.
Your assertion that Nori has B12 is downright wrong.
B12 is only synthesized by microorganisms.
There are plenty of vegetarian options, but if you are vegan, you have to rely on fortified products and supplements.
This has nothing do to with where you happen to live.
You can check recommendations from physicians, researchers and most importantly Vegan associations all across the globe to the see this is true.
“The Vegetarian Resource Group (VRG) suggests that vegans need to have reliable sources of vitamin B12 in their diets. (1) The Vegetarian Nutrition Dietetic Practice Group (VNDPG) of the Academy of Nutrition and Dietetics says that all vegetarians (including vegans) should include a reliable B12 source in their diets, such as fortified foods or supplements. (2) And The Vegan Society goes so far as to state, “What every vegan should know about B12: the only reliable sources of B12 are foods fortified with B12 and supplements.” (3)“
I have seen people get sick ignoring these issues in a vegan diet.
“According to vegan expert and co-author of Vegan for Life, Jack Norris, RD, there are no reliable sources of B12 in plants, contrary to many rumors about sources, such as tempeh, seaweeds, and organic produce. Plants have no B12 requirement, therefore they do not have any active mechanisms to make or store it. When you find B12 in plants, it is due to contamination, which is not a reliable source. Many seaweeds have B12 analogues, through their symbiotic relationship with cobalamin-producing bacteria, however the evidence is not clear that this form is active B12 in humans. And fermented foods, such as tempeh, are not fermented through B12-producing bacteria, thus they are not a source of B12. Rumors about bacteria on the surface of organic produce producing B12 have not been verified. “Chlorella may improve B12 status, but it’s by such a small amount that I wouldn’t rely on chlorella for B12,” adds Norris. Norris stresses that, unless a food obtained from multiple regions consistently improves B12 status, it should not be relied upon as a source of B12.“
A vegan diet can be a healthy and sensible choice for people living in a modern society with access to supplements and fortified foods as well as the care and knowledge to use them. Otherwise it is not an appropriate diet for humans, especially not outside of the modern Western organic supermarket and supplement infrastructure.
B12 is the only real deficiency vegans experience and it's easily solved by taking a supplement. B12 isn't some miracle vitamin, exclusive to animal products either. It's produced by bacteria in the soil and since we're usually sterilizing our food, it's not usually found on our produce anymore. That's why livestock are getting it supplemented, just the way vegans are supplementing it. It's not even like eating meat and animal products saves you from B12 deficiency as a big chunk of the population is actually deficient.
> Veganism is associated with a slew of health problems.
As compared to what?
Yes. You can’t get B12 on a vegan diet. Vegans supplement it.
Side note about B12: a B12 deficiency from a vegan diet largely comes from environmental sterilization. B12 is bacteria-produced. You could drink stream water and get your B12 “naturally”, too.
What you say may be true, but regardless of how it came to be, it's my understanding that b12 deficiency is much more common in vegans than meat eaters. So vegans do have to be careful in the short term. Maybe in the long term they should campaign for b12 enriching common vegan foods.
As always, an incredible amount of disinformation regarding B12.
The fascination with B12 is largely to do with non-vegans looking for a reason to eat meat. They ‘think’ B12 is the proof they need to continue their lifestyle.
I’ll also add that, as a vegan of 8 years who takes no supplements or eats any special fortified foods, my B12 levels have always tested as slightly above the recommendations. That’s with me taking daily acid reflux medication also.
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