View Full Version : [bio] B12 in mushrooms - and unwashed plants

May 10th, 2004, 12:02 PM
According to this (http://www.cul.slu.se/information/publik/veganekhstud2001.pdf) article, there is 0,26 mcg vitamin B12 in 100 g mushrooms.

Dec 11th, 2006, 01:57 PM
Here's another one about B12 in mushrooms:

Mushrooms were found to contain 0.32-0.65 mg per gram of B12, allowing just 3 g of fresh mushrooms to provide the RDA of this vitamin. Vegetarians may find this a useful way of getting this important nutrient.

Dec 11th, 2006, 02:42 PM
Apparently, its the dirt on the mushrooms that contain B12.

From http://www.ivu.org/nzvs/nutri/vb12.htm ....

Mushrooms cultivated on manure enriched compost will contain vitamin B12. If the mushrooms are not over washed before use they will contain some B12. There is 0.26ug of vitamin B12 in 100g of mushrooms. A serving of 4-6 mushrooms weighs 75g.

Dec 11th, 2006, 07:27 PM
I always wash my mushrooms twice. I hate any dirt on them, so I probably "wash away" the b12. :p

Dec 11th, 2006, 08:17 PM
I know what you mean Tigerlily. They can be all gritty if your not careful can't they! You can get kits to try and grow mushrooms yourself. Anybody ever tried?

Dec 12th, 2006, 11:50 AM
I remember about 10 years ago in Australia, mushrooms were advertised on TV as 'meet for vegetarians' because of the B12. Now they no longer make that claim and mushroom bags just say that they have a range of B vitamins. I agree that it's from the dirt or whatever. A bit of dirt doesn't hurt.

Dec 12th, 2006, 04:14 PM
Ehhhh, when you have caked on manure on your mushrooms it may not hurt but it's super nasty.

Aug 29th, 2009, 10:05 AM
About B12 in mushrooms on Jack Norris blog: http://jacknorrisrd.com/?p=588

Oct 3rd, 2009, 06:15 AM
thanks very much for posting this medus :)

May 22nd, 2010, 11:00 AM
This is probably the study Jack Norris is talking about (see below). The abstract itself doesn't say the exact levels that was found.

Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus) (http://www.ncbi.nlm.nih.gov/pubmed/19552428) PMID: 19552428

Vitamin B12 is the active corrinoid produced in cultivated white button mushrooms (Agaricus bisporus).
Koyyalamudi SR, Jeong SC, Cho KY, Pang G.

Centre for Plant and Food Science, College of Health and Science, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797, Australia.
Analysis of vitamin B(12) in freshly harvested white button mushrooms ( Agaricus bisporus ) from five farms was performed by affinity chromatography and HPLC-ESI-MS techniques. The vitamin B(12) concentrations obtained varied from farm to farm, with higher concentrations of vitamin B(12) detected in outer peel than in cap, stalk, or flesh, suggesting that the vitamin B(12) is probably bacteria-derived. High concentrations of vitamin B(12) were also detected in the flush mushrooms including cups and flats. 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.

I think I'll start to count not only the articles that claim that they are presenting information about the only plant that contains B12, but also the articles that discuss how many portions one would have to eat of this plant to meet the RDA. :-)

If these plants were found to contain high concentrations of B12, why would one have to eat "from 7 to 326 cups of mushrooms to meet the RD"? Something is wrong here...

May 22nd, 2010, 11:07 AM
Is the B12 actually in the mushrooms or is it just if they aren't washed? :confused:

May 22nd, 2010, 11:14 AM
English isn't my native language, but dosn't "High concentrations of vitamin B(12) were also detected in the flush mushrooms" mean that the mushrooms are cleansed - or am I making a fool out of myself now? :)

May 22nd, 2010, 12:09 PM
It sounds as if the B12 is actually in the mushrooms but as some people have raised the question of whether or not cleaning the mushrooms has something to do with it I am a little confused! :)

Dec 1st, 2010, 04:43 PM
Well I'm fine for b12 then, I eat an insane amount of mushrooms everyday and I never bother to wash them.

Dec 1st, 2010, 05:49 PM
Don't believe everything you read. :-)

I think the washing aspect of this is highly overrated, because I haven't seen one single study that compares washed plants that are supposed to carry some B12 with unwashed plants.

Unfortunately, nothing B12 related is simple. 0.26 mcg B12 (example in post #1) is also too little if you happen to be exposed to "B12 killers". Trust me - we all are!

Plus - there's no need to feel certain that all mushrooms contain bioavailable B12 even if some mushrooms do. Maybe, in a decade or two, there will be enough studies to provide info that we can trust, in all settings/in terms of reliable daily intake, without having to wonder if the B12 we get is both active, well and alive. RIght now, we don't.

I still think the existing studies are very important: not only do they point at plants/products that need more research (eg. in terms of the ratio between active/inactive B12), but they say something about all the plants out there which have been identified as B12 carriers of some sort.

I'm sorry if all this is confusing! If it is of any help, the info non-vegans use to verify their intake of B12 and other nutrients is also rather flakey: it usually both ignores the "(B12) killer" aspect of it all, and rarely contain proper info about the rate between active, bioavailable B12 and inactive B12 analogues.

Clueless Git
Dec 2nd, 2010, 12:48 AM
Well I'm fine for b12 then, I eat an insane amount of mushrooms everyday and I never bother to wash them.
Me too Goober ..

Eat 'em raw and dont even bother to do more than just brush any loose dirt off of them.

Dec 2nd, 2010, 02:31 AM
0.26 per 100g is just not worth bothering with. Even if you eat loads of unwashed gritty mushrooms I very much doubt anyone would manage the 400g required daily to reach the 1mcg EC RDA on a regular basis let alone the revised 5mcg that has been suggested as a new RDA.

Dec 2nd, 2010, 05:50 AM
Me too Goober ..

Eat 'em raw and dont even bother to do more than just brush any loose dirt off of them.

have you seen and studies confirming that there's enough bioavailable B12 in that dirt to keep your B12 levels good?

Dec 2nd, 2010, 06:16 AM
0.26 per 100g is just not worth bothering with. Even if you eat loads of unwashed gritty mushrooms I very much doubt anyone would manage the 400g required daily to reach the 1mcg EC RDA on a regular basis let alone the revised 5mcg that has been suggested as a new RDA.
I always differentiate between the two B12 "approaches", so to speak, when looking at such numbers. We need, IMO, to have two parallel ways of thinking about these issues, because there are always, so to speak, two entirely topics going on, at least from the perspective of that major group of people (95-100% of the Western population) which aren't vegans or vegetarians.

A) How much B12 does a human living in a normal/modern/western lifestyle need to keep his levels healthy?
B) Is there something 'wrong' with eating a plant based diet - only - "from nature's side", so to speak, meaning that vegans will get diet related nutrient deficiencies while people on other diets won't?

Like it or not, but for most people in the world, B is much more important than A. And - from a B perspective, 0.26 mcg B12/100 g, just to use one specific study on mushrooms, is a very important finding, just as the other, dozens of findings about B12 in other plants, water, leaves, bark, soil and so on are.

Why? Because of the myth myth about vegans having to eat 'half a kg mushrooms' or '50 cups of spinach etc to meet the B12 requirements. Some insist that vegans would have to do this even if they would live in a 'natural world'. Most people will understand that although vegans and non-vegans today may need to take supplements to address the nutrients they miss, but they find it hard to accept that a vegan diet is a good choice if that diet more or less would have been the only one which automatically means a need for supplements.

B12 levels are always microscopic (except in supplements). The great thing about consuming B12 in really microscopic levels is that the smaller the B12 amounts are, the closer the absorption rate gets to 100%. In high levels, it's down to around 5%.

In that famous 'natural' world, one could easily drink two liters of water - or more - per day. According to this (http://wiki.answers.com/Q/How_much_food_does_the_average_human_eat_per_day) non-scientific resource, an average human eats 8 pounds a day. (This seems very high to me.... That's 3-4 kilograms!) Anyway - unlike today - everything had to be done manually throughout our predecessors evolution. Finding food, making it, transporting oneself/food, gathering/hunting - and so on. A lot of manual work - which means a higher intake of both food and water, and therefore a higher intake of the nutrients we today may get too little of. All the food was also organic. And often totally fresh.

I'll write more later, but if we for now divide the numbers above by two, and say that we eat and drink only 2500 gram/day, how much would B12 one need - per 100g of food/drink - in order to consume, say, 5 mcg? The answer is 0.2 mcg. In that same, 'natural' world and lifestyle we would also eat more than we do today because there would be no TVs or computers etc = more body activity, and a higher need for food and water. Plus - we wouldn't need the 1 or 3 or maybe 5 mcg/day B12 we may need today: we would need a lot less, because many of the "B12 killers" didn't exist back then.

I could go on about this forever (and probably will :-))) ), but if I look at all the facts we have, and combine them with some educated assumptions - which we need to do, since some facts are missing, we'd most likely get more than the B12 we need from plants and water in a 'natural' world/with a natural lifestyle. We would also be a lot more outdoors throughout the year, meaning higher vit. D levels, which are associated with a better calcium levels and therefore higher B12 levels. And so on.

But, as we all know - we don't live in that natural world, and even some of those who did/do, may not have been be nutrient conscious enough to know what to eat/drink and what to avoid in order to keep their B12 levels healthy. That's one of the reasons I'm skeptical about the 'don't wash your plants and you're safe-'philosophy'. It has never been proven to work for most people/most vegans.

Dec 2nd, 2010, 10:34 AM
Good point Korn.

Dec 3rd, 2010, 08:48 AM
There are a few other things that are worth mentioning in this context as well. B12 has been reported as existent in lentil seed sprouts and other germintaed pulses, in (organic) spinach, barley and soy, in mushrooms and many other plants. Sometimes B12 is found in plant stems, sometimes in the roots, and then there's this theory that B12 in plants mainly is to be found on the surface of the plants - from dirt - if they are not washed.

I think we can safely assume that the B12 amounts in dirt on the plants most likely is similar to the B12 levels found in the soil (http://www.veganforum.com/forums/showthread.php?3532-B12-in-soil-and-soil-depletion-of-nutrients) the plant came from - or, at least, I'll assume that for now.

I don't know how much dirt one possibly could consume if one wouldn't wash the plants one is eating, but - just to use an almost random example: let's say that as much as 1% of what you eat is plain dirt. I'm sure the number is lower, but that's not important right now. So - if you eat eg. 100g lettuce or sprouts or carrots and don't wash the plants first, 1% of what you eat is dirt in this theoretical example. That's one gram of dirt.

If we assume that 100g soil/dirt contains 1 mcg B12, 1 g. dirt contains only 0.01 mcg B12. Again - this is only an example; the B12 ratio will be higher for light weight plants with a large surface (lettuce, spinach etc), and lower for compact plants like carrots and beets with a low 'surface pr. gram' ratio.

Now, in that 'natural world', maybe 0.1 mcg B12 per 100g plants - from dirt alone - wouldn't be so bad? If they ate 2600 g food every day, that would be 2.6 mcg B12 only from the dirt... That's the current UK RDA for pregnant women! And - don't forget that back in th day humans would also get B12 from water and from dirt/soil in water...

But read on:
• We probably don't eat as much as 1% dirt
• B12 synthesis has been reported to cease after 4 days.
• If a plant is cut off from it's source of cobalt and B12 friendly bacteria (read: soil), and then sent to a distributor>store>your fridge, the B12 levels, when you eat the plant, are lower than when it was picked.This is true for the the possible B12 in the dirt on the plant as well.
• B12 supplements are kept in non-transparent jars because B12 doesn't like light. But plants aren't kept or transported in light proof boxes. This affects both the possible B12 in the plant, and definitely affects the possible B12 in the dirt on it's surface.
• Plants grown in greenhouses need water. Most likely, they are watered with water that has been chlorinated. B12 doesn't like chlorinated water.
• Sprouted seeds and pulses have also, most likely, been exposed to chlorinated water - even the home sprouted ones.
• Not only that, but even if you would manage to get plants (and dirt on it) that hasn't been exposed to chlorinated water, fluorized water, food irradiation, light etc... you may drink some coffee or water made from chlorinated water with/after the meal. Chlorine is so efficient that it will work inside your stomach after you have been drinking it. So the B12 from that perfect, organic, fresh and dirty leafy green plant almost made it to your blood stream - but the 'enemy' still won. :) The B12 was killed by the water you had with your meal, or the coffee you had after it. If you had coffee, or something with alcohol or sugar in it - not only would the chlorinated water used to make the drink affect your B12 level, but the sugar/coffee/alcohol would have a negative effect as well.

This may be way too detailed for some of you, but IMO it's important to look at these things, and not just vaguely claim things about 'the natural world' or that we're safe if only we eat some dirt, or insect droppings on plants, or if the plant is organic.

Writing all this made me think that maybe the facts we have about leafy, green plants may partially exist not because these plants are leafy as such, or because they are green (most leafy plants are green anyway), but since these plants have such a big surface compared with all other plants. Maybe there actually is some healthy stuff happening in their surface that we don't know much about yet - maybe not due to the dirt itself, but due to a mix of humidity/light/oxygen and good bacteria.

Even if dirt on plants would only contain only 10% of that 1 microgram B12 /100g I mentioned above - in other words, not 0.1 mcg but 0.01 mcg, if our ancestors ate as much as 3+ kg food per day, they'd probably would get some B12 from that dirt - given that the plants of course were organic (they always were), fresh etc.

0.01 mcg B12/100 g means 0.3 mcg b12/day from dirt alone, which actually is three times as much as dr. Herbert once wrote we would be OK with. He did ignore some important factors back then, but in the natural-world-scenario, most of the B12 killers aren't relevant, food was eaten fresh and all that. And if we both would get 0.3 mcg B12 from dirt back then, + B12 from natural water resources (one study suggested than we'd get the B12 we needed per day from one liter of river water), and some of the plants themselves also contained B12, since the world wasn't 'denaturalized' back then, we would probably have no B12 problems at all.

Re. the B12 absorption rate being reduced if we consume high portions of B12 in one go: this doesn't apply much to the turbo-microscopic amounts we are talking about here, if anything at all. On the contrary, the knowledge we have about B12 absorption rate being most efficient at low B12 amounts supports the idea that the microscopic amounts of B12 in plants are much more useful than they seem to be at first sight. Unlike supplements with 25 or 100 or 1000 mcg B12, most of the B12 would actually be absorbed, the 'expensive urine argument' wouldn't exist.

So - getting some B12 from 'dirt' could have had some relevance back in the day. It seems that dirt today has almost no impact on the B12 levels in our blood stream. That said, for mushrooms, which also have high 'surface - per gram' ratio since they are so lightweight - maybe the picture is a little different than for many other plants, but I still wouldn't count on mushrooms as a reliable B12 source.

The average height for humans have increased a lot over the years. This is probably related to an increased/exaggerated intake of growth stimulating food, like growth hormones in meat and milk. If a human average male is, say, 180 cm today, and the average used to be 140-150 cm, the body weight and volume is higher, which means that the B12 needs probably are higher as well.

But increased body weight today doesn't necessarily mean increased ability to find/consume or absorb B12. On the contrary, the various reasons for people being overweight may be the same reasons that their B12 levels are reduced (high sugar intake, for example).

Our species seem to be in the middle of an evolutionary intermezzo, so to speak. We are exposed to all the side effects of the modern world: less exercise, less fresh air, less sunlight, pollution, a vast amount of B12 killers, synthetic fertilizers and poorer soil, reduction of good bacteria in water - combined with a higher intake of growth hormones, bacterial intestinal overgrowth due to the high meat intake and so on, synthetic medicines etc. So far, we simply lack all the info we need to deal with the sudden changes that has happened in human evolution. We can't move backwards in time or pretend that cars and factories and synthetic fertilizers don't exist - the only solution is to deal with the situation and gather more facts.

In spite of being 99.9% convinced that we wouldn't need animal product in that 'natural' world in order to get the B12 we need, the biggest mistake we IMHO can make now is to ignore that we all - in so many ways - live a very 'denaturalized' life, even if we eat food from health food stores and would stop washing our carrots.

Sep 18th, 2012, 11:33 PM
From a discussion over at scienceforums.net, this finding has been quoted:

A 2005 study from Italy found significant amounts of vitamin B12 analogue in mushrooms (33 (http://www.veganhealth.org/b12/plant#fn33)). 250 g of P. nebrodensis contained 4.8 g of vitamin B12. They used an immunoenzymatic assay. From the paper, it appears that the soil did not have organic waste of any kind. It is not clear if the B12 analogue was active.

Aug 9th, 2014, 09:53 AM
According to the above source, raw, white mushrooms contain 0.04 mcg B12/100g. If what you eat and drink would contain only 0.04 mcg B12/100 g, 2.13 kg (see below), 0.04 mcg/100 g would give you circa 1 mcg B12/day.

According to http://wiki.answers.com/Q/How_many_pounds_of_food_does_the_average_person_ea t_each_day :

The US Dept. Of Agriculture estimates that the average person in the United States eats .5 lbs of meat, 1.6 lbs of dairy products, .2 lbs of fats and oils, .8 lbs of fruits, .7 lbs. Of vegetables, .5 lbs of grains, and .4 lbs of sugars per day for a total of 4.7 lbs. of food per day. To see the USDA study, follow this link: http://www.usda.gov/factbook/chapter1.htm

4.7 lbs = 2.13 kg.

The previous post is about Funcia di basilicu (P. nebrodensis) (http://unknown-endangered.tumblr.com/post/50285817690/funcia-di-basilicu-pleurotus-nebrodensis), which - if we translate 4,8 mcg/250 g the more standard mcg/100g way of looking at things, contained 1.92 mcg/100g. As usual, it's important to differentiate between active and inactive B12, and as usual, it's easer to just take a supplement than to rely on small amounts of B12 from a variety of plants which aren't documented to contain bioavailable, active B12.