Reducing consumption of animal products is a choice with both moral and practical consequences. Last summer I found myself in contact with many vegans who cared a lot about the moral consequences, but had put little effort into learning about or managing the practical consideration of removing animal products from their diet. I’ve suffered a lot due to bad nutrition, so this made me very concerned. With a grant from the Survival and Flourishing Fund, I launched small a pilot project to give nutritional tests to 5 vegans and near-vegans from the Lightcone Office, which they could use to choose supplements that would hopefully improve their health.

My long-term goal was for everyone to have accurate information on their personal nutritional costs of veganism and make informed choices about how to handle them, with the first line solution being supplements. My goal for the pilot was to work out practical issues in testing, narrow the confidence interval on potential impact, and improve the nutrition of the handful of people. This report is on phase 1: getting the testing done and supplements started. It is aimed at people who might want to run a similar program at scale; if you are interested in running this for yourself I recommend checking out Tuesday’s post on iron deficiency.

Tl;dr: I found rampant iron deficiencies, validating the overall concern. The procedure I used has a lot of room for improvement. 

The Experiment

I gave nutrition tests to 6 people in the Lightcone office. 

The ideal subject was completely vegan, had never put any effort or thought into their diet, and was extremely motivated to take a test and implement changes. This person does not volunteer for studies, so I ended up with 4 vegans or near-vegans who had put somewhere between 0 and a lot of thought into their diet, 1 vegetarian, and 1 extremely motivated omnivore I used to test out the process.  In addition, one hardcore vegan contributed results from private testing. I did not poll the ~vegans on their exact diets.

Unless otherwise stated the results exclude the omnivore.

I gave each of these six people a Genova Metabolomix+ test, ordered from, with the iron add-on. This test was selected for being recommended by doctors I trust (in part because they prefer urine to blood testing), having extremely easy-to-read results, being nearly comprehensive (with the unfortunate absence of vitamin D), and because I hoped urine collection at home would be easier than blood draws at a lab. Foreshadowing: I was wrong about that last part.

I also gave people the option of an add-on to determine what variant of the MTHFR gene they have. MTHFR can affect how one processes certain B vitamins, and certain variants can necessitate a more expensive form of supplements.

Several people (although not everyone) scored with undetectably low iron. I offered them follow-up blood tests, which one person accepted. An additional vegan contributed blood test results without urine results.

As of publication all subjects have received their first round of results and started supplements of their choosing. 

The original plan was to retest in 3-6 months after people began supplements, using the same urine tests.

My initial predictions

I expected the big shortages to be B12, iron, and vitamin D, the first of which has very few* natural vegan sources and the latter two of which are scarce, although not absent, in vegan sources. This makes it pretty unfortunate the original test did not include vitamin D. 

[*B12 is (maybe?) naturally found in some (but not all) seaweeds and algaes, in at least one kind of mushroom, and in nutritional yeast (but possibly in the wrong format?). It’s also added to many wheat products in the US, so if you eat enough wheat and aren’t going out of your way to get unfortified wheat that’s a strong source]

Relative to the mainstream I wasn’t very concerned about protein consumption. Vegan proteins are a little less abundant, a little harder to digest, and have a less ideal distribution of amino acids, but are basically fine as long as you don’t pile on additional constraints.

One reason I was concerned was that lots of people I polled were piling on additional constraints, like keto or gluten-free, and still not doing anything to manage nutrition. I expected a smattering of deficiencies from these people, and to a lesser extent from everyone, as their restrictions and tastes cut off random nutrients. These could have been in any almost nutrient.

I expected everyone to be fine on vitamin C because it is abundant in both produce and processed food (where it’s used as a preservative).


(including only vegans and near-vegans)

  1. ¾  vegan testers had severe iron deficiencies in their urine tests.
    1. The one who didn’t had both a stunning dietary intake of iron, and a parent who 23andMe believes to have a genetic predisposition to excessive absorption of iron.
    2. An additional vegetarian tester was not deficient.
    3. One of these retested with a blood test and scored low normal (~30). However this person was already taking iron supplements at the time of the test. 
    4. A bonus blood-only participant tested between 13 and 20, meaning they’d be considered deficient by some standards but not others.
  2. There were no B12 deficiencies, probably because everyone was already on B12 supplements. 
  3. One tester had a lot of deficiencies, including vitamin C, to the point I suspect it’s a problem with digestion rather than diet. 
  4. Everyone had at least one amino acid deficiency, including the person eating over 100g of protein/day. I don’t know how big a deal this actually is.
  5. The urine test did not include vitamin D.  Of the 2 blood tests, both had low-normal vitamin D.
  6. Excluding the person with across-the-board deficiencies, there were scattered other deficiencies but nothing else to consistently worry about. People were mostly in their tests’ green zone, with occasional yellow and red.

What does this mean?

Only one near-vegan out of 5 had solidly good ferritin levels. As I discuss here, that’s a very big deal, potentially costing them half a standard deviation on multiple cognitive metrics. 

There’s no control group, so I can’t prove that this is a veganism problem. But I’m quite suspicious.

There were no other consistent problems, so broad-spectrum testing is probably overkill for people with no known problems. 

Retrospective on the project

What worked

I consider the core loop of the study as vindicated as can it be at this stage. 

  • Deficiencies were identified, and the primary one was one of the three I predicted.
    • And another of the three, B12, was probably absent because people treated it preemptively. Note that people were inconsistent in what they took so I can’t say definitively what they were on during testing.
  • In the counterfactual timeline the shortages were probably identified much later if at all. No one who participated had any plans for testing, including people with obvious symptoms and people whose doctors had previously recommended testing.

This will be less impressive if supplementation doesn’t turn out to fix anything, but it’s an extremely solid start.

Other things that went well:

  • Having the room in my budget for unplanned additional testing, so I could add in serum iron tests when it became obvious they were necessary.
  • Creating a shopping list with links. I was worried this was somehow taking advantage of people (since I used affiliate links), but removing a decision and several steps from the ordering process seems to have been pretty crucial. 
  • Bypassing the need for doctors’ visits to get a test. Given how long it took people to order tests I think doctors’ appointments would have killed the project entirely. 
  • The Lightcone ops team was extremely cooperative and got all of the vitamins I suggested into the office.

Difficulties + possible changes

Potential changes are framed as recommendations because I am deeply hoping to hand off this project to animal advocates, who caused the veganism in the first place. 

  1. The test ordering workaround was not as good as I had hoped
    1. I’d originally hoped to just hand participants a box, but they had to order the tests themselves.
    2. In order to get iron + genetics tests people had to call rather than order online. This is non-standard for the provider and two people had to call twice to insist on what they wanted.
    3. Tests took a long time to ship, and a long time to return results after shipping. The lab alleges this is a supply chain issue and there’s nothing to be done about it. 
    4. Those two together turned into a pretty big deal because they made it very hard to plan and people lost momentum.
    5. In combination with the results showing few problems beyond iron I recommend deemphasizing full spectrum urine tests and focusing on blood tests for iron (and vitamin D), and making those convenient, perhaps by bringing a phlebotomist to the office.
    6. Another option would be to bring in a medical practitioner, who can order tests for other people, to manage tests so the office can be stocked with them. This of course fails to solve the problem for anyone not in the office.
    7. There are home tests for vitamin D and iron specifically, but I have no idea if they’re any good.
  2. Ideal test subjects (completely vegan, never done nutritional testing or interventions, promptly puts in the effort to do these tests and act on them once I suggest it) were even thinner on the ground than anticipated.
    1. I knew there wouldn’t be many, but I didn’t think it would be so hard to get five people pretty close to that profile. 
    2. I loosened restrictions and still consistently found problems, so recommend lowering the eligibility bar for testing in future rounds, especially since that was always the plan. The strict requirements in this round were an attempt to make the signal as loud as possible.
  3. Getting everyone tested was like herding cats. Beyond the problems with the test distributor, some participants needed repeated reminders to order, one lost a test, results went missing… it was kind of a nightmare.
    1. One advantage of focusing on blood tests would be to cut down on this, especially if you bring the phlebotomist to the office.
  4. At points I was uncomfortable with the deference some participants showed me. I was as clear as I possibly could be that this was a best-effort from a knowledgeable amateur kind of thing; they were responsible for their own health and I was a nonexpert trying to provide some logistics help. I nonetheless got more than one person bringing me problems not even related to the nutrition project, and insisting I tell them what to do.
    1. Recommendation: bring in a skilled nutritionist. They can both give better advice than me and devote more time to helping people. 
  5. I initially misread the protein results (which are delivered in terms of “how deficient are you?” rather than “what’s your current level?”, making 0 the best possible score). Luckily I knew I was confused from the beginning and no one had taken any actions based on my misinterpretation. More broadly, I’m just a woman who’s had some problems and read some stuff, I expect my suggestions to be better than nothing but far from the maximum good it would be possible to do.
    1. Recommendation: bring in a skilled nutritionist
  6. I underestimated the amount of time and especially emotional labor this project would need. I was hoping to bluff my way through that until people got on supplements, at which point the improvements in health would be their own motivation. I think I always overestimated how well that would work, but it was especially wrong because all the problems with the tests drained people’s momentum.
    1. Recommendation: I still think you should bring in a skilled nutritionist
  7. Many of the participants were moving frequently and not in the office by the time their results came in (because they took so long…), so they had to buy supplements themselves. Given the option I would have selected people consistently in the office, but as mentioned I was already managing trade-offs around participants.
    1. Recommendation: ask for more money to give everyone their first month of supplements and a convenient pill planner.

Next Steps

I previously planned to give people the same urine test 3-6 months after they started supplements. That no longer seems worth it, relative to the cheaper and more convenient blood tests. 

It’s not actually clear a formal follow-up is that useful at all. I initially planned that because I expected a wide range of shortages such that literature reviews wouldn’t be helpful. But there was only one real problem, and it has a richer literature than almost any micronutrient. So I don’t think another 5 people’s worth of scattered data is going to add much information. 

So the next step for this as a project would be mass blood testing for B12, iron, and vitamin D. 

Feeling motivated?

If this has inspired you to test your own nutrition, I haven’t done anything you can’t do yourself. Both the urine and blood tests are available at, and if you have a doctor they’re quite likely to agree to testing, especially if you’re restricting meat products or fatigued. I have a draft guide of wisdom on supplementation I’ve picked up over the years here, although again, I’m not a doctor and only learned how to digest food last May, so use at your own risk. 

Thank you to the Survival and Flourishing Fund for funding this project, Lightcone for hosting, and all the participants for their precious bodily fluids.

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iron levels are mentioned (by Preston Estep's Mindspan) as being particularly bad for the brain (iron increases dementia rates!). Iron increases ROS in the cell by catalyzing the Fenton reaction. As long as one is not feeling too fatigued from it, I don't think that having low-moderate iron levels is a bad thing 

I have been near-vegan for many years (though I occasionally eat eggs) and my iron/ferritin levels are both well within the normal range. I've posted my bloodwork here - My main health issue is low bone density, though this will not affect quality of life for several decades (and zoledronate is a pro-longevity intervention for this). I am now taking Vitamin K2 and may consider medications for this in the future, if needed, and we will almost certainly have lab-grown salmon by then.

Bryan Johnson (vegan except for collagen peptides) also just posted a tweet about his recent results, which seem near-optimal (ofc, he is also much more disciplined about this than most people). has a good guide on the deficiencies that I'm more concerned about (taurine and carnosine being among them). Much of is vegan.

As a result, men in Crete have a biological age about five years younger. They also have ferritin levels about half the average level in Zutphen, which is consistent with their significantly lower risk of stroke, cancer, diabetes, and heart attack.

According to Japan’s 2006 National Health and Nutrition Survey, people in Japan and Okinawa also have low ferritin, and a large proportion are iron deficient (50 percent of women of childbearing age have ferritin below 20 ng/mL). Japanese also have low hemoglobin.

The World Health Organization defines anemia as hemoglobin levels below 12 g/dL for women and 13 g/dL for men. This difference in minimum acceptable value for men and women is arbitrary, simply because women tend to have lower levels—not because a value between 12 and 13 g/dL is unhealthy for men. The average hemoglobin levels for older Japanese (including centenarians) are often even lower than this minimum. In a publication from 1996, average hemoglobin levels in healthy Japanese centenarians were reported to be 11.5 g/dL for women and 11.8 g/dL for men. We can’t be certain that their hemoglobin has always been so low, but we can be sure that their diets and lifestyles haven’t changed much, and these values are lower than those measured in elderly people in Mindspan Risk countries.

Estep recommends ferritin of 10 to 40 ng/ml (mine is 89)...

Animal studies show that high iron feeding increases body iron stores and shortens lifespan, and adding tea to the diet reduces body iron and increases lifespan. In late 2015, a study of people who ate a Mediterranean-style diet (characterized mainly by less meat and more fish) had larger brains and key brain structures and less atrophy than frequent meat eaters. The difference between the two groups that ate the most and least meat was equivalent to five years of brain aging. And of course there are the Mindspan Elite and their lower body iron stores and lower rates of Alzheimer’s. Taken together, this evidence is very strong, but these studies don’t show direct cause, as a clinical trial does. That’s been done too. In 1991 the iron chelator drug deferoxamine* (which binds iron and renders it inactive) was shown to slow the progression of Alzheimer’s disease.


Firstly, just wanted to caution that vegans should be very careful about claims of unfortified plant-based foods containing adequate B12. Although some seaweed/algae/mushroom types contain molecules that are structurally similar to B12, they may not have the same nutritional benefits. e.g. see Some people engage in motivated reasoning around this topic, so I think it is good to be cautious when evaluating such claims.

I strongly support B12 testing for vegans. This is only my anecdotal experience, but I had grown up eating little meat and dairy for various reasons, and at one point decided to cut it out entirely as I felt that it would be more moral. It did not occur to me at all that veganism could have negative side-effects, given how widely it is publicized, so I didn't bother looking into it. I'm certain that there are many others who have done the same.

Later, much to my chagrin, I was diagnosed with severe Vitamin B12 deficiency, which has robbed me of 2+ of my most productive years due to loss of physical strength, nerve pain, extreme fatigue, and possibly loss of cognitive ability.

For a description of what the condition can do to even the greatest of minds, see Eugene Wigner's description of the great mathematician David Hilbert's condition after contracting pernicious anemia (the condition was named before scientists realized the anemia + symptoms were caused by lack of B12) in his autobiography:

I was quickly and deeply disappointed. I found Hilbert painfully withdrawn. He had contracted pernicious anemia in 1925 and was no longer an active thinker. The worst symptoms of pernicious anemia are not immediately obvious, and Hilbert's case had not yet been diagnosed. But we knew already that something was quite wrong. Hilbert was only living halfway. His enormous fatigue was plain. And the correct diagnosis was not encouraging when it came. Pernicious anemia was then not considered curable.

So Hilbert suddenly seemed quite old. He was only about 65, which seems rather young to me now. But life no longer much interested him. I knew very well that old age comes eventually to everyone who survives his stay on this earth. For some people, it is a time of ripe reflection, and I had often envied old men their position. But Hilbert had aged with awful speed, and the prematurity of his decline took the glow from it. His breadth of interest was nearly gone and with it the engaging manner that had earned him so many disciples.

Hilbert eventually got medical treatment for his anemia and managed to live until 1943. But he was hardly a scientist after 1925, and certainly not a Hilbert. I once explained some new theorem to him. As soon as he saw that its use was limited, he said, "Ah, then one doesn't really have to learn this one." It was painfully clear that he did not want to learn it.

I gauged Hilbert's plight at our very first meeting. After that, I saw him only about five times more the rest of the year. I did what little I could for him, but I could not make him younger or remedy his anemia. I had come to Göttingen to be Hilbert's assistant, but he wanted no assistance. We can all get old by ourselves.

thank you. I had only glanced at non-animal B12 and was trying to be fair to vegans, if my sources were bad that's extremely useful to know. And if is being rigorous about this that increases my respect for them.

A relevant experience of mine: after being vegan for ~1 year, I got my blood tested to see if there was anything I should watch out for. It turned out that my iron reserves were low, so I was told to take iron supplements. One year later I got another blood test where my iron levels came back as too high. My doctor was confused until I told him I still sporadically took iron supplements; he told me to stop immediately, and that as a male I didn't need to supplement iron much.

Now I feel like I'm in a damned-if-I-do-damned-if-I-don't limbo; it would be great to have some sort of framework of when/if to take iron supplements.

Is there not an option to take a lower dose of iron supplements?

Sure, but my point was I don't know what dose per unit time to take.

One what later? Year, month?

Whoops, I meant year. Edited.

Did you notice supplementing iron making you feel better? If so, perhaps it would be worth getting several tests and adjusting your dose until the tests come back consistently normal?

I didn’t feel a difference; I guess because it was my iron reserves that were low, not my actual iron levels.

But yeah, if it does continue to be a problem I will do something like that.

Thanks for this post! I'm guessing the main drive for this project is just compellingly exemplifying that nutrient deficiency is also present in the rationalist community, so as for more people to treat their dietary health seriously? Even though there's no a priori reason to expect nutrient deficiency not to happen amongst non-dietary-conscious rationalists.

I say that because (and sorry for maybe being blunt) the sample size is so small compared to the rich existing literature on this topic, that this feels more like an emotionally compelling "take care of yourself" advice than any scientifically relevant discovery.

On a related note:

The ideal subject was completely vegan, had never put any effort or thought into their diet, and was extremely motivated to take a test and implement changes.

I don't understand why the target subject here should be people who have never put any effort or thought into their diet. That way you don't get relevant evidence about the prevalence of iron deficiency among veg*ns, but only the almost trivial conclusion that people who don't take any care of their dietary health have some deficiencies.

I don't understand why the target subject here should be people who have never put any effort or thought into their diet. That way you don't get relevant evidence about the prevalence of iron deficiency among veg*ns, but only the almost trivial conclusion that people who don't take any care of their dietary health have some deficiencies.


It makes plenty of sense to me; I think the vast majority of people don't put any thought into what vitamins they might be deficient in. I was vegan in college for ethical reasons, and I was in the school's vegan / animal welfare club, and the entire year I was in that club I didn't hear a single mention of taking supplements to offset what we weren't getting through our diet. I had never heard about B12 or creatine supplementation until I came to the rationalist community. 

And in any case if Elizabeth is trying to study the impact that ~veganism has on micronutrient levels, then comparing [~vegans who don't take supplements] to [omnivores who don't take supplements] will give the clearest data.

I don't doubt your anecdotal experience is as you're telling it, but mine has been completely different, so much so that it sounds crazy to me to spend a whole year being vegan, and participating in animal advocacy, without hearing mention of B12 supplementation. Literally all vegans I've met have very prominently stressed the importance of dietary health and B12 supplementation. Heck, even all the vegan shitposts are about B12!

comparing [~vegans who don't take supplements] to [omnivores who don't take supplements] will give the clearest data

Even if that might be literally true for scientific purposes (and stressing again that the above project clearly doesn't have robust scientific evidence as its goal), I do think this won't be an accurate representation of the picture when presented to the community, since most vegans do supplement [citation needed, but it's been my extensive personal and online experience, and all famous vegan resources I've seen stress this], and thus you're comparing the non-average vegan to the average omnivore, giving a false sense of imbalance against veganism. As rational as we might try to be, framing of this kind matters, and we all are especially emotional and visceral with regards to something as intimate and personal as our diet. On average, people raised omnivores have strong repulsion towards veganism (so much so as to override ethical concerns), and I think we should take that into account.

It sounds like you're really passionate about vegan nutrition. Can I suggest channeling that into sharing resources that help naive vegans? Even if you don't think they're representative they clearly exist, and if the problem can be solved by linking to existing resources that seems incredibly high return. 

Tbh I'm not that passionate, I feel like I'm just doing the necessary minimum to stay completely healthy?

Anyway, of course! But most are just really basic reviews/explainers that are one google search away, to get the big picture of what you need. Some of these are:

And regardless of these resources you should of course visit a nutritionist (even if very sporadically, or even just once when you start being vegan) so that they can confirm the important bullet points, whether what you're doing broadly works, and when you should worry about anything. (And again, anecdotically this has been strongly stressed and acknowledged as necessary by all vegans I've met, which are not few).

The nutritionist might recommend yearly (or less frequent) blood testing, which does feel like a good failsafe. I've been taking them for ~6 years and all of them have turned out perfect (I only supplement B12, as nutritionist recommended).

I guess it's not that much that there's some resource that is the be-all end-all on vegan nutrition, but more that all of the vegans I've met have forwarded a really positive health-conscious attitudes, and stressed the importance of this points.

I've also very sporadically engaged with more extensive dietary literature, but mainly in Spanish (for example, Lucía Martínez's Vegetarianos con ciencia).

There was one very high up guy who ran around vegan ea for years yelling at anyone who suggested veganism required the slight bit more effort, thought, or money. He left in 2018 or 2019 for unrelated reasons but I think he may have done serious long term damage to ea vegan culture in particular.

That's a pity to hear, since undoubtedly any dietary change or improvement does require some thought (and we also should think about our dietary health regardless of them). That said, I do generally feel the required effort, thought, and money are way less than mainstream opinion usually pictures.

Regarding effort and thought, my experience (and that of all almost all vegans I've known who didn't suffer of already-present unrelated health issues) was that the change did required some effort and thought the first months (getting used to cooking ~15 nutritious comfort vegan meals, checking the labels, possibly visiting your nutritionist for the first time), but it quickly became a habit, as customary as following an omnivore diet.

And regarding money, the big bulk of a healthy vegan diet aren't meat substitutes, processed burgers etc., but vegetables, legumes, cereals... some of the cheapest products you can buy, especially when compared to meat. So a healthy vegan diet is indeed usually cheaper than an omnivore diet, even including the B12 supplementation, which is really cheap, and maybe even including the sporadic nutritionist visit and blood testing (in case they're not already part of your public health/medical plan), unless doctor visits are absurdly expensive in your country.

Since this comment got linked to, and we are throwing around anecdotal evidence, I'll add mine: the animal rights vegan club at my uni had at least one individual quite keen on supplementing (not in a wacky way, mostly commonsensical) and I didn't hear any push back from the other members. And none of them ever heard of EA. And my very leftist vegan roommate had B12 & Creatine (I assume they took them). And I assume EA is at a equal, likely higher epistemic standpoint.

When I look back on these comments, it looks to me like you'd rather nutritional difficulties with veganism weren't discussed, even when the discussion is truthful and focuses on mitigations within veganism. Is that true? If not, what do you think is the right way to discuss the challenges of veganism? I don't believe the current system is working, given that multiple people (some in the comments here) describe converting to veganism naively. 

Hi Elizabeth! Thanks for reaching out. Excuse my delay in response, and the length of this reply. It felt important to communicate the nuances in my views (and the anecdotal experiences, which in our past exchanges might not have come through.

you'd rather nutritional difficulties with veganism weren't discussed, even when the discussion is truthful and focuses on mitigations within veganism

That's not my position. To the extent the naive transition accounts are representative of what's going on in rat/EA spheres, some intervention that reduces the number of transitions that are naive (while fixing the number of transitions) would be a Pareto-improvement. And an intervention that reduces the number of transitions that are naive, and decreases way less the number of transitions, would also be net-positive.

My worry, though, is that signaling out veganism for this is not the most efficient way to achieve this. I hypothesize that

  1. Naive transitions are more correlated with social dynamics about insuficient self-care not exclusive (nor close to exclusive) to veganism in rat/EA spheres.
  2. Independently of that, a message focused on veganism will turn out net-negative, because of the following aggregated collateral effects:
    1. Decreasing the number of overall transitions too much. Or better said, incentivizing some thought-patterns and dynamics upstream of that decrease, that have even worse consequences than the decrease itself.
    2. Relatedly, incentivizing a community that's more prone to ignoring important parts of the holistic picture when that goes to the selfish benefit of individuals. (And that's certainly something we don't want to happen around the people taking important ethical decisions for the future.)

More on 2. below (On framing), but let me get into 1. first.

I was very surprised to hear those anecdotal stories of naive transitions, because in my anecdotal experience across many different vegan and animalist spaces, serious talk about nutrition, and a constant reminder to put health first, has been an ever-present norm. And, at the same time, a recognition that turning vegan, even with all these nutrition subtleties, is not nearly as difficult as people imagine it (certainly in part due to selection effects).[1]

I hypothesize that the distributional shift is due to properties of the social dynamics and individual mindspace that rat/EA circles inadvertently encourage, especially on wide-eyed newcomers. The same optimizing mindset leading to "burn-out / overwork / too much Huel / exotic unregulated diets / not taking care of your image / dangerous drug practices linked to work" around these spaces seems to me to be one of the central causes of these naive transitions. I think this is also psychologically linked to the rational justification I've heard from some x-riskers: their work is just too important to care about anything else. Obviously that backfires.

Now, even given the above, it is coherent to believe that, despite this common root, veganism in particular is such a prominent example, with so many negative consequences, that a straightforward intervention pushing the motto that veganism presents tradeoffs and can be difficult or not for everyone, is net-positive. After all, this is kind of a quantitative question. I claim that's not the case, and it's related to collective blind spots we shouldn't ignore, which brings me back to 2.

On framing:

One thing that might be happening here, is that we're speaking at different simulacra levels. I'm not claiming you're saying anything untrue, just that the consequences of pushing this line in this way are probably net-negative.

Now, I understand the benefits of adopting the general adoption of the policy "state transparently the true facts you know, and that other people seem not to know". Unfortunately, my impression is this community is not yet in a position in which implementing this policy will be viable or generally beneficial for many topics. And indeed, on some priors it makes sense that a community suddenly receiving an influx of external attention will have to slowly work up to that, if it is at all possible.[2]

I believe one of the topics is veganism, because of the strong intuitive aversion individuals across the board feel towards changing their diet for ethical reasons (and, I claim, this aversion is irrational and should be counteracted and scrutinized accordingly). In my anecdotal experience (of many years discussing veganism with vegans and non-vegans), an almost-total fraction of the justifications for not transitioning to a vegan diet easily fall to "Is that your true rejection?" (even if the best route is not always to mention that explicitly, of course).

I expected to see that change in EA circles. Unfortunately, that has not been my anecdotal experience. The animalist part of EA, so to speak, is very strongly concentrated in a few individuals (or better said, sub-communities), who have taken this issue seriously enough, and many times are even directly working on animal welfare. But when you move slightly away from that space into neighboring sub-communities (say, a randomly sampled alignment researcher), defensive motivated reasoning on the topic seems to go up again.[3]

And there are instances in which I've obtained direct evidence that individuals in decisive positions are not reasoning correctly about the tradeoffs involved. As an example, consider that some offices / programs / retreats don't offer (as the free lunch for their members) a completely vegetarian menu (let alone vegan).

From the outside, I don't understand how this decision can make sense for any rat/EA space. Even if it were true that veganism requires some more efforts, it would be because of the complications related to health tracking or food planning. Those are not present in this case. The food is served, for free. Organizers can put the extra effort to make sure that the offer is nutritionally complete each day, or across the week (as also happens with omnivore menus). But whoever is not vegan need not worry that hard about all that, since they'll be eating omnivore outside the office. And whoever's vegan should worry about that, just because they're vegan. Having meat in this menu doesn't directly improve anyone's health.

And the few times I've seen this "from the inside", that is, I've heard organisers' reasoning about this decision, they really didn't seem to have meaningful arguments, and appealed to a general notion of individual freedom which I think is not a good ethical proxy, and if translated to other domains would lead to bad "not taking side-effects seriously", or "not taking the dangers of social dynamics seriously".

I have, of course, heard the obvious argument (although not from organizers) that x-risk research is so important that, if having a vegan menu might slightly turn off a single valuable researcher, it's not worth it. This of course resonates a lot with the optimizy mindspace referenced above. And here I'll just say that I don't think this is the kind of desperate community we want to build. That this can just the same turn off ethically conscious people, who we do want in our community. And that this mindset is very correlated with the "unconstrained obsession with talent" that has led the community to being partly captured by ML community, weird epistemic areas incentivizing bad elitism and power dynamics, etc. In simpler words, I think this blows past some healthy and necessary deontological fences (more in the next section).

I also cannot help but feel suspicious that these practices are so comfortably presented as the default, and alarmed (in some precautionary sense) that grant money is being used to finance something as horrible, and vast, and openly debated, as animal exploitation (more in the next section).

Let me also note that I don't agree that your posts (and the ensuing comments and conversations) were focused on mitigations within veganism, due to their framing. Even if you truthfully discussed these mitigations, the general tone skeptical of the viability and importance of veganism was very clear, and it is obvious which message most people will get out of this post. I'd love to live in a world were I can trust your readers to Bayesian update and ignore framings, but it'd be self-delusional to think this will be the case in this situation, given the obvious strong pulls everyone has towards motivated ignorance of veganism (and the evidence I've obtained about that also inside this community), and how the framing / headliners / first-order updates from your posts resonate with those repeated one-dimensional rationalizations.

A background ethical disagreement:

One thing that might also be happening is just that we disagree ethically. After all, if I didn't care at all about veganism (or related individual ethical practices), I wouldn't care about how many vegans are lost, as long as naive vegans are decrease (ignoring second-order effects on community epistemics, as discussed above). And indeed, it is popular amongst some rationalists to doubt the possibility that animals can suffer, something I strongly ethically disagree with.[4]

But I'm not sure that's the main driver of our disagreement. If we disagree about how hard to push veganism, or how deeply to consider the negative consequences of having a less vegan community, it might be because of a disagreement about where the utilitarianism / deontology line should be in this topic. (After all, you could very strongly worry about animal suffering, and nonetheless bet absolutely all your efforts on x-risk research, because of being a naive Expected Value Maximizer.) Or equivalently, about how bad the consequences for community dynamics can be, and whether it's better to resort to rule utilitarianism on this one.

As an extreme example, I very strongly feel like financing the worst moral disaster of current times so that "a few more x-risk researchers are not slightly put off from working in our office" is way past the deontological failsafes. As a less extreme example, I strongly feel like sending a message that will predictably be integrated by most people as "I can put even less mental weight on this one ethical issue that sometimes slightly annoyed me" also is. And in both cases, especially because of what they signal, and the kind of community they incentivize.

The right way to discuss these challenges:

As must be clear, I'd be very happy with treating the root causes, related to the internalized optimizy and obsessive mindset, instead of the single symptom of naive vegan transitions. This is an enormously complex issue, but I a prior think available health and wellbeing resources, and their continuous establishment as a resource that should be used by most people (as an easy route to having that part of life under control and not spiraling, similar to how "food on weekdays" is solved for us by our employers), would provide the individualization and nuance that these problems require. Something like "hey, from now on, those of you that follow any slightly unconventional diet, or have this other thing, or suffer that other thing, can go talk to these people, and they will help you do blah" would sound pretty good, and possibly a welfare multiplier for some people. It certainly sounds better to me than just broadcasting the message "veganism is hard, consider the tradeoffs and either search for help, or drop veganism". Additionally, "hard" is very variable, and the nuance of it and your observations will get lost.

Something like running small group analytics on some naive vegans as an excuse for them to start thinking more seriously about their health? Yes, nice! That's individualized, that's immediately useful. But additionally extracting some low-confidence conclusions and using them to broadcast the above message (or a message that will get first-order approximated to that by 75%) seems negative.

It feels weird for me to think about solutions to this community problem, since in my other spheres it hasn't arisen. But thinking about which things that happened in those spheres could have contributed positively, the first things that come to mind are: talks / events / activities about sports and health (or even explicitly nutrition), memes about nutrition (post-ironic B12 slander, etc.), communal environments where this knowledge is likely to be shared (like literal cooking).

I also observe that the more individualized approach might work better for a more close-knit community, and that might be especially unattainable now. Maybe there's some other way to bootstrap this habit. Relatedly, I'd feel safer about some more oversight with regards to some health practices in general (especially drugs, and especially newcomers). But I observe that anything looking like policing is complicated.

In any event, I'm no expert in community health, and my separate point stands that I think broadcasting that message is net-negative right now, because of the obvious bottom-line people would extract from it.

Thanks for reading all of that. Next weeks are busy so I might again take a bit long to reply. Nonetheless, I saw in your last post that you're thinking about vegan epistemics. Just in case you'd find that valuable, I'd be willing to discuss those thoughts as well, or provide opinions on concrete topics, or just talk about my experience. But of course, no problem if you don't.

  1. ^

    And, to be fair, I have even observed this health consciousness in the few EAs I know who are very vocal about their veganism and animalism (they are few because inside EA I've been closer to AI safety than animal welfare).

  2. ^

    I could also note that this situation is slightly different from a straightforward "these people believe this false fact". More accurately, the truth value of this fact hasn't been brought to their attention, because of a complex web of learned emotional and mental habits. I'm talking here about focusing on those habits, as opposed to the practice of veganism in particular.

  3. ^

    It's obviously hard to draw the boundary of motivated reasoning. I have observed pretty clear-cut cases, but let me just leave it at "these intelligent people are not thinking about / taking seriously / maintaining up to their epistemic standards this aspect of their life as much as they should according to some of their own stated preferences or revealed preferences (and as clearly they are able to)".

  4. ^

    Due to my views on consciousness and moral antirealism, I think deciding which physical systems count as suffering is an ethical choice (equivalent to saying "I care about this process not happening"), and not a purely descriptive one.

Hi Martin- I really appreciate the thought and detail that went into this post, it was well worth the wait.

I have a lot of things I want to clarify, but suspect it just doesn't make sense to do so in this format. One option would be to try out LW's new Dialogue format. However I'd need to start this week, and it sounds like that's not an option for you. If this is a thing where money can help, I have some grant money and a good dialogue would be a good use of it, but I understand it probably can't. In which case hopefully you'll see my next post when things clear up and we can talk then. 

Thank your for your words.

I'd be down for a Dialogue, but indeed I cannot engage in that too soon (maybe only mid October).

But as explained in my message, I remain slightly worried about the memetic effect of your possibly publishing posts within the same framing. I completely understand you have no need to delay any publication, but because of that I'd be especially interested in ensuring that views like mine are correctly represented, and thus answering your clarifying questions seems important.

Would something like "you write the list of clarifying questions, and I write up my first-pass responses by this Saturday (even if not as deep as a Dialogue)" work for you? Completely understandable if it doesn't.

Also, I'm interested in hearing where you think the disagreement lies (out of the possibilities I've outlined above).

One thing that struck me reading your post was the number of times I wanted to say "no, you".  Issues where you see mistreatment of vegans or bad epistemics from omnivores, and I see the symmetric bad behavior from vegans[1]. My guess is we're both accurately describing things we've seen, and we're both activated and protective after engaging in a lot of interactions where the other party was acting in bad faith. And those situations just take a lot of time to wind backwards, even though I think we've both done admirable jobs of it here.

I few things I thing are important and could possibly be addressed in a quick response:

You're worried my posts will lead more people to eat meat. AFAIK the practical effects have been dozens of vegans getting tested (with some portion of those starting vegan supplements), and one and a half people saying the posts were a component leading them to consider adding meat in once or twice a week (and those came much later, not as a result of the testing posts). People are more likely to report supplements than diet changes, but I also think my posts deserve more responsibility for the tests and supplements than for the dietary changes. It would mean a great deal to me to have this empirical fact either explicitly disagreed with or acknowledged. 

But you're right my posts probably weren't optimal for maximizing the number of vegans in the world. Probably because I wasn't optimizing for that, because I don't think it's as important as you or other vegan advocates do. I consider this a direct consequence of EA vegan advocacy's failure to provide basic nutritional education to the vegans it created. If you don't want omnivores running your vegan education, provide it yourself. 

You bring up EA/rat optimization drive as the root cause of nutritional issues. I think your description is confused but there is some core vibe I agree with, and I agree people would be better off relaxing that cosntraint on themselves. But I have no idea how to fix it. Meanwhile, for most existing naive vegans there's a $20 bill on the floor, in the form of some simple tests and supplements. I do write posts along the lines of "chill out" and maybe they're even helpful, but they have nowhere near the surgical problem-solving capacity of "hey here is a major problem you can fix with a pill."

And yes, I do talk about $20 bills for omnivores (or just unrelated to diet) when I find them, but most of the problems with omnivorism are more complicated or involve giving up things people like, which is just much harder. 


  1. ^

    E.g. you see all the places not offering vegan meals. I see vegan meals at Lightcone and Constellation. EAG serves only vegan meals (even when the caterer is unequipped for this). My impression is CEA's general policy is vegan-only. The upcoming Manifest conference explicitly promises vegetarian and vegan food. Atlas Fellowship workshops' chefs would technically serve meat, but you could tell their focus was on the vegan food. 

    You see omnivores as having bad epistemics and not giving their real reasons. I see the omnivores I knew in 2016 who were actively pursuing information about animal suffering and reducitarianism/ameliatarianism, until bad vegan advocates ground that curiosity down.  Advocates who wouldn't acknowledge the existence of trade offs, or differences in ability to be vegan, or wouldn't let the discussion be about anything except veganism and vegetarianism even when vegetarianism was higher net suffering than the complicated thing the omnivore was considering. 

Thank you, and sorry again for my delay!

As I understand it, our main disagreements seem to be:

  1. How many vegans, or more accurately how much general seriousness towards animal ethics, will be lost as a result of your kind of interventions.
  2. How bad it is for this to happen.

Let me start with 1.

I also think my posts deserve more responsibility for the tests and supplements than for the dietary changes. It would mean a great deal to me to have this empirical fact either explicitly disagreed with or acknowledged.

While I acknowledge these observed benefits, I do want to challenge that these observations are nearly enough to be sure the effects are net-positive, because of the following: The negative effects of the kind "everyone treats veganism less seriously, and as a result less people transition or are vocal about it" will be much more diffused, hard-to-track, and not-observed, than the positive effects of the kind "this concrete individual started vegan supplements". Indeed, I fear you might be down-playing how easy it is for people to arrive (more or less consciously) at these rationalized positions, and that's of course based on my anecdotal experience both inside and outside this community. But I am even more worried about the harder-to-pin-down communal effects, "tone setting", and the steering of very important sub-areas of the EA community into sub-optimal ethical seriousness (according to me), which is too swayed by intellectual fuzzies, instead of actual utilons.

Let me now turn to 2.

But you're right my posts probably weren't optimal for maximizing the number of vegans in the world.

Of course, I too don't optimize for "number of vegans in the world", but just a complex mixture including that as a small part. And as hinted above, if I care about that parameter it's mainly because of the effects I think it has in the community. I think it's a symptom (and also an especially actionable lever) of more general "not thinking about ethics / Sincerity in the ways that are correct". As conscious as the members of this community try to be about many things, I think it's especially easy (through social dynamics) to turn a blind eye on this, and I think that's been happening too much.

If you don't want omnivores running your vegan education, provide it yourself.

My experience is that vegans usually just have enough trouble fighting their way through people's cognitive dissonance, so that doing "public stunts" remarking health aspects is not the best ethical use of their public resources, and actually focusing on animal ethics is more positive. I do agree, of course, that in private communications (or publicly available places which are not the focus of stunts), the health measures recommended when transitioning should be explicited.

And, to be honest, that's what I've always experienced in private vegan circles, as I've mentioned before. For example, people are so conscious of B12, Iron and Omega-3 that they've just become a post-ironic meme. But it seems from your messages that this hasn't been the case in some important private spaces of the community in the past. Unfortunately, even if that is the case, I don't think it switches the balance so that "public interventions" start to be the ethically most positive. I think the most efficient way to repair those damages are still private interventions.

Meanwhile, for most existing naive vegans there's a $20 bill on the floor

And I think the most ethically positive way of picking them up is not public interventions about veganism that have other negative side-effects (that I claim are larger), but a mix of private interventions about veganism (enacted through a more effective net of support and help, for example by having specialists available to decrease the activation barrier of getting these important health actions started), and public interventions about health and care more in general. I'd be super excited to see things like that happen, but of course I know they're easier said than done, and I'm no expert in community health.

I see the omnivores I knew in 2016 who were actively pursuing information about animal suffering and reducitarianism/ameliatarianism, until bad vegan advocates ground that curiosity down.

Here I can only say "Wow, the difference in our reported experiences is big, and I don't know exactly how to account for that". My experience has been that I / friends have always had to "plant the idea" of animal exploitation maybe even being sometimes questionable. When someone comes at you having read stuff online about veganism, and interested in animal ethics, they have basically already gone past the first shallow arguments, they're already taking animal ethics seriously, and you just counsel them on practical matters (like indeed health). And not only have I found "we have always had to bootstrap this curiosity" (on people who we knew actually don't want to kill babies, so we just were presenting information or new perspectives to them), but also that vegan advocates correctly reward their way through the omnivores' well-meant advances (like reducitarianism) (while still stating, of course, that veganism is the moral baseline for them whenever it is attainable, which in my experience has been almost always).

E.g. you see all the places not offering vegan meals. I see vegan meals at Lightcone and Constellation.

To be clear, I wasn't complaining about places not serving vegan food. I was complaining about places serving meat. In my first long comment I give some thoughts on why I find this net-negative ("From the outside, I don't understand...").

I hypothesize that the distributional shift is due to properties of the social dynamics and individual mindspace that rat/EA circles inadvertently encourage, especially on wide-eyed newcomers. The same optimizing mindset leading to "burn-out / overwork / too much Huel / exotic unregulated diets / not taking care of your image / dangerous drug practices linked to work" around these spaces seems to me to be one of the central causes of these naive transitions.


I think I have a better understanding of what you mean by this now. I think you're right that it's present, but wrong that it's the major cause of poor diet among vegans.

You describe vegan education happening informally in vegan-heavy spaces. EA is one of very few places where you can have a high density of vegans, but not have real vegan elders around to pass on the metis. I think that broke the chain of education, and left a lot of people bereft. And this is invisible to people in the established movement because if they were in those spaces, the spaces wouldn't have that problem. 

One reason I think this is that a friend tells me the exact same thing happened in straight edge punk, a movement that does not otherwise have a lot in common with EA. Another is that compulsive optimization doesn't lead people to neglect something as simple as iron.

If the chain of education had been continued I think there would still be some problems caused by the optimization drive, and those would indeed have a fair amount in common with EA omnivore problems. 

Just want to quickly flag that, based on my anecdotal experience, the vegan communities I was thinking of in which nutrition was thoroughly discussed didn't involve learning from vegan elders either. They were mostly students, and had learned about nutrition from the internet, books, memes and visiting professionals, and in fact I recall them as being more heavy on the nutrition talk than the older vegans I've met (even if the elders also supplemented etc.). I feel like the adequate seriousness with which they treated nutrition came more from a place of positive and optimistic "let's do things the right way" (to be a good example, to maintain some important boundaries that will allow us to help sustainably, etc.).

Another is that compulsive optimization doesn't lead people to neglect something as simple as iron.

I disagree, I think unfortunately this and worse can happen in some environments and mental spaces.

Thank you. I'd want to investigate more before fully updating, but this does speak directly to my crux, and your position makes more sense now. 

I say that because (and sorry for maybe being blunt) the sample size is so small compared to the rich existing literature on this topic


I agree 100% that the sample size is too low to compete with existing literature, and the error bars are too wide to make it very useful on prevalence. Luckily...

My goal for the pilot was to work out practical issues in testing, narrow the confidence interval on potential impact, and improve the nutrition of the handful of people.

As a bonus, the results let me make an informed guess on which part of the existing literature to engage with, which I published last week

I do take issue with calling the existing literature "rich". It's scarce and mostly extremely low quality.  The 5 person study doesn't fix that and the upcoming 20 person one won't either,  but nutrition literature is bad even by medical standards. 

Nice! I guess I was just worrying about framing, since most people who see this will only skim, and they might get the impression that veganism per se induces deficiencies, instead of un-supplemented veganism (especially since I've already seen a comment about fixing this with non-vegan products, instead of the usual and recommended vegan supplementation).

It's scarce and mostly extremely low quality.

And totally agree. Nonetheless, I do think available reviews can be called rich in comparison to a 5 or 20 person study.

I guess I was just worrying about framing, since most people who see this will only skim, and they might get the impression that veganism per se induces deficiencies, instead of un-supplemented veganism

The post is about testing vegans for deficiencies specifically so the author could provide (presumably vegan) supplements to people with deficiencies. It would be very strange to read this as an argument that you can't solve deficiencies in a vegan diet with supplements.

How does urine testing for iron deficiency work? I was under the impression that one needs to measure blood ferritin levels to get a meaningful result... but I might be wrong?

They're looking for byproducts, but it indeed didn't work very well and that's why I've refocused on blood testing.

Hmm, I'm a bit surprised that iron/B12 deficiencies showed up so much. Lots of vegan food like oat and soy milk are enriched/fortified, so if you drink your coffee with oat milk and pour some soy milk in your cereal, it goes a long way toward avoiding being low on iron and B12. Of course, this is highly individual, as is most of nutritional advice. As for Vit D... if you are fair-skinned, just being in the morning/afternoon sunshine frequently enough and with some skin exposed ought to help.

Fortified milks usually don't contain much iron. The soymilk in my fridge (Silk unsweetened) has 120% RDA of B12 but only 6% RDA of iron.


I find that the domain does not give any results. I think the correct url is (no 's' in the url). Is this the one you used?

Only one near-vegan out of 5 had solidly good ferritin levels. As I discuss here, that’s a very big deal, potentially costing them half a standard deviation on multiple cognitive metrics. 

There’s no control group, so I can’t prove that this is a veganism problem. But I’m quite suspicious.

I might have noticed lower iron levels on the nutrition facts of vegetables, as well as all other vitamins and minerals (relative to a few years ago,  but I wasn't paying much attention a few years ago). Like, a 1-cup serving of organic peas having 6% iron, 4% vitamin B, and 1-0% on everything else, which was weirdly low for basically half a day's intake of vegetables (this was ~november-december, all vegetables I could find at Whole Foods and Trader Joes in Foggy Bottom DC). It might have had something to do with FDA labelling though. I looked it up and the internet had surprisingly little to say other than that soil/fertilizer quality is degrading. It might plausibly be worth doing an experiment.

(To clarify, that's 6% RDI, not 6% by volume, which would be worrying.)

I'm confused. Are you saying 1 cup of organic peas is "half a day's intake of vegetables" for you?