# vegans and bone broth **URL:** \ **Category:** Factual Questions\ **Created:** [April 11, 2017, 6:10am UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222 "2017-04-11T06:10:37Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [April 13, 2017, 4:27pm UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222/41 "2017-04-13T16:27:03Z")
> [@Dag\_Otto](#): > > The OP hasn’t returned. She really is thin-skinned. **Moderating** Let’s avoid personal remarks in GQ. No warning issued, but this is inappropriate. Colibri General Questions Moderator ---
**Author:** ![constanze](https://avatars.discourse-cdn.com/v4/letter/c/f9ae1b/32.png) [@constanze](https://boards.straightdope.com/u/constanze)\ **Post date:** [April 13, 2017, 4:33pm UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222/42 "2017-04-13T16:33:41Z")
> [@Broomstick](#): > > Incorrect - there is NO naturally occurring source of B12 other than animal-derived food. You MUST supplement. Might also be a question of Definition: is Supplement only referring to taking a pill with isolated B12 - or also to Special vegan Food (e.g. Tofu) “enriched” with B12 specially for vegans? Additionally, there’s the japanese algae [Nori - Wikipedia](https://en.wikipedia.org/wiki/Nori) which is usually recommended - though studies seem to contradict ? > [@](#): > > It has also been found to contain sufficient vitamin B12 to prevent vitamin B12 deficiency in rats.[19] Though nori has long been considered to be an important source of vitamin B12 for vegans,[20][21] its vitamin B12 may actually not be biologically available to humans. It may contain cobalamin analogues which block absorption of B12.[22][23] A study on mice found that nori (Pyropia yezoensis) contains a significant amount of bioactive vitamin B12, not the inactive analogues.[24] However, a study showed that in humans both dried and raw nori reduced the vitamin B12 status.[25][26] Seems we Need more studies on that. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [April 13, 2017, 5:20pm UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222/43 "2017-04-13T17:20:39Z")
> [@](#): > > Quoth **Broomstick** : > > Incorrect - there is NO naturally occurring source of B12 other than animal-derived food. You MUST supplement. Not quite true. The correct statement would be that there are no naturally-occurring plant-derived sources of B12. B12 is produced by bacteria, and there might be some dietary source naturally high enough in the relevant bacteria without relying on animal sources. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 13, 2017, 6:43pm UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222/44 "2017-04-13T18:43:46Z")
Yes, intestinal bacteria produce B12, that’s where ruminants like cows get their supply of the stuff (along with the occasional bug eaten along with grass). It’s just that in humans it’s manufactured so far downstream in the gut that it isn’t absorbed. So, yeah, you can eat your own shit and get sufficient B12 but so far I’m not aware of any human society where that is the norm. Fecal contamination of food IS one potential source of B12 in societies where hygiene is less than that of the 21st Century industrialized civilization. The problem is that along with B12 you can pick up a lot of nasty diseases with that. And, I might point out, that fecal contamination is still of animal origin. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [April 13, 2017, 6:49pm UTC](https://boards.straightdope.com/t/vegans-and-bone-broth/784222/45 "2017-04-13T18:49:13Z")
> [@constanze](#): > > Might also be a question of Definition: is Supplement only referring to taking a pill with isolated B12 - or also to Special vegan Food (e.g. Tofu) “enriched” with B12 specially for vegans? The B12 used to enrich that tofu has to come from somewhere. People vegan for ethical reasons are going to want to know the ultimate source of that B12 > [@](#): > > Additionally, there’s the japanese algae [Nori - Wikipedia](https://en.wikipedia.org/wiki/Nori) which is usually recommended - though studies seem to contradict ? > > Seems we Need more studies on that. Currently, it seems that the algae B12 is not available to humans. One problem with testing seaweed is that in its natural state it’s quite likely to have small crustrations/plankton and/or animal feces on it - both of which would be sources of B12, but might be offensive to some people. Again, this gets back to food hygiene - the more modern/advanced/industrial practices that strip out contaminants would also strip out those sources of B12. People who ate the seaweed with less cleaning or processing might well be getting some B12 with it, but it’s not coming from the algae. Sure, next week there might be a discovery that overturns my statement, but I have yet to see evidence of a B12 source for humans that wasn’t ultimately of animal origin. [Previous page](https://boards.straightdope.com/t/vegans-and-bone-broth/784222.md?page=2)