Any 3rd or 4th generation vegans?

[Third Person Groove]

Hey guys

Im curiously and mostly id like to come up with some type of strong argument against this guy... I suspose if there are any 3rd or fourth generation vegans it would be a good point to make.?.


Youtube video title ( veganism and vegetarianism isnt sustainable in the long term.)

https://youtu.be/1_E3iMrq-UA

[carnap]

An anecdote of a 3rd or 4th generation vegan isn't going to tell you much about the impact of vegan diets. You'd need to compare 3rd and 4th generation vegan population to other populations to see if there are any statistically significant differences.

[Third Person Groove]

An anecdote of a 3rd or 4th generation vegan isn't going to tell you much about the impact of vegan diets. You'd need to compare 3rd and 4th generation vegan population to other populations to see if there are any statistically significant differences.

Did you listen to the guy in the video? What do you think about all of his points?

[brimstoneSalad]

We have plenty of healthy second generation vegans, and that's really all people should need to know. Anything else is just insane fear mongering. You can always make nonsense fear-mongering about epigenetics, even claiming it's something that doesn't show up until the 100th generation.
Maybe we need to be cannibals, because after 500 generations of not eating any human flesh we all die? We all have cannibal ancestors carrying us. The clock is ticking, we have to get back to our roots soon or perish! Just silly.

In terms of populations, B-12 was discovered in the late 1940s and only made commercially in the mid to late 1950s. It's been about 70 years.

There hasn't really been time for third generation vegans, and that's also why there have never been vegan populations. People had to have at least consumed dairy or eggs, or some small amount of meat/sea food to maintain vitamin B-12 status. Something particularly important in pregnancy.

It's possible that some lake water is rich in B-12, but not the well or river water most people drink (and for good reason, lakes can be contaminated and result in a lot of parasitic problems).

Even if we ignore ALL of the mechanistic data which says veganism (with B-12 and attention to nutrition) is fine and animal products have health risks, the relative sparsity of epidemiological data should not be concerning.
We know the trends in longevity. Mediterranean and Okinawan diets are associated with longer lives, and the trend is in the direction of less animal products.
If somebody is really skeptical, it might make sense for that person to go *almost* vegan, but it certainly doesn't make sense to keep eating large amounts of animal products. But demanding that kind of thing is absurd; we know why there have not been vegan populations, we don't need to speculate on magical missing vitamins. If somebody personally is afraid to trust science and the overwhelming evidence we already have, that's up to that person, but fear mongering against veganism for others is just ridiculous... and also evil given the impacts on animals the environment and other human beings.

[Third Person Groove]

We have plenty of healthy second generation vegans, and that's really all people should need to know. Anything else is just insane fear mongering. You can always make nonsense fear-mongering about epigenetics, even claiming it's something that doesn't show up until the 100th generation.
Maybe we need to be cannibals, because after 500 generations of not eating any human flesh we all die? We all have cannibal ancestors carrying us. The clock is ticking, we have to get back to our roots soon or perish! Just silly.

In terms of populations, B-12 was discovered in the late 1940s and only made commercially in the mid to late 1950s. It's been about 70 years.

There hasn't really been time for third generation vegans, and that's also why there have never been vegan populations. People had to have at least consumed dairy or eggs, or some small amount of meat/sea food to maintain vitamin B-12 status. Something particularly important in pregnancy.

It's possible that some lake water is rich in B-12, but not the well or river water most people drink (and for good reason, lakes can be contaminated and result in a lot of parasitic problems).

Even if we ignore ALL of the mechanistic data which says veganism (with B-12 and attention to nutrition) is fine and animal products have health risks, the relative sparsity of epidemiological data should not be concerning.
We know the trends in longevity. Mediterranean and Okinawan diets are associated with longer lives, and the trend is in the direction of less animal products.
If somebody is really skeptical, it might make sense for that person to go *almost* vegan, but it certainly doesn't make sense to keep eating large amounts of animal products. But demanding that kind of thing is absurd; we know why there have not been vegan populations, we don't need to speculate on magical missing vitamins. If somebody personally is afraid to trust science and the overwhelming evidence we already have, that's up to that person, but fear mongering against veganism for others is just ridiculous... and also evil given the impacts on animals the environment and other human beings.

Thank you lol you always have incredible replies.

[carnap]

We have plenty of healthy second generation vegans, and that's really all people should need to know. Anything else is just insane fear mongering. You can always make nonsense fear-mongering about epigenetics, even claiming it's something that doesn't show up until the 100th generation.

I don't think there is "plenty" of second generation vegans but nobody is really keeping track. But the mere existence of second generation vegans is by no means what you need to know. Firstly the vast majority of second generation vegans are going to be young (vegan diets were much less common 20+ years ago) so you don't know how these people are going to age yet and secondly you need studies that have compared the population of second generation vegans to a reference population. Until those studies exist all you have is anecdotes.

Even if we ignore ALL of the mechanistic data which says veganism (with B-12 and attention to nutrition) is fine and animal products have health risks, the relative sparsity of epidemiological data should not be concerning.

What mechanistic data tells us that vegan diets are fine? There are so many gaps in our mechanistic knowledge that you really cannot conclude much about vegan diets on purely mechanistic data. And there is no major scientific organization that makes a blanket claim about "animal products" having health risks and none of them claim that vegan diets are some how healthier or even recommend them.

Discussing gaps in research should never be considered "fear-mongering", skepticism is the default position in science not what you wish to believe.

[brimstoneSalad]

Firstly the vast majority of second generation vegans are going to be young (vegan diets were much less common 20+ years ago) so you don't know how these people are going to age yet

How they're going to age? More absurdity.

We know young people can become vegan and be healthy into adulthood. We know vegan pregnancies can be healthy and yield healthy children. We have all of the pieces.
Assuming it's magically different when you put them all together is like creationists denying "macro-evolution" but accepting "micro-evolution".
A properly planned vegan diet is suitable for all stages of life, it's as simple as that.

and secondly you need studies that have compared the population of second generation vegans to a reference population.

No we don't.
We really only need to know vegan pregnancies are healthy if properly planned, and vegan children on properly planned diets are healthy, etc.

We know all of those things; doctors are perfectly capable of assessing the health of their patients without doing some large study.

What mechanistic data tells us that vegan diets are fine?

All that we have. Humans only require nutrients, not particular source of those nutrients, and vegan diets can be planned appropriately to include all of the nutrients humans need.
Dietetic organizations agree. You dismiss the conclusions of professionals because you don't like the conclusions.

There are so many gaps in our mechanistic knowledge that you really cannot conclude much about vegan diets on purely mechanistic data.

There are gaps in mechanistic data on everything, doesn't mean we can't come to reasonable conclusions in terms of overwhelming probability.
Also, gaps don't mean you can insinuate the opposite as you like to do.

And there is no major scientific organization that makes a blanket claim about "animal products" having health risks and none of them claim that vegan diets are some how healthier or even recommend them.

Dietetic organizations discuss the potential benefits of vegan diets, you just discount their views on the matter because you don't like them.

Discussing gaps in research should never be considered "fear-mongering"

It is when professionals don't find those gaps concerning. The big problem is that people in the developed world are eating too much meat, not too little of it.

skepticism is the default position in science not what you wish to believe.

Skepticism may be, but the margin of reasonable skepticism based on the unknown there is very small. We know from overwhelming epidemiological evidence that less meat is better, so we're comparing the effects of little meat to no meat, and it's not surprising that those differences are going to be small given the small differences in the diets.

Skepticism would entail recognizing that veganism may even be a little healthier than eating some animal products, and you just don't know, but that the evidence suggests that however it comes down the difference isn't that dramatic and isn't worth raising alarm over. As long as vegans are taking B-12 there's no reasonable cause for concern.

People are suffering and dying in droves due to the effects of climate change, not due to the effects of going vegan. There's simply very little risk involved and the potential payoff is far greater; both in terms of health (because we also have to remember there's a chance of improved health), and effect on the world around us.

[carnap]

We know young people can become vegan and be healthy into adulthood. We know vegan pregnancies can be healthy and yield healthy children. We have all of the pieces.
Assuming it's magically different when you put them all together is like creationists denying "macro-evolution" but accepting "micro-evolution".
A properly planned vegan diet is suitable for all stages of life, it's as simple as that.

Its not "that simple" because we lack the research to support such a statement. For example there are virtually no studies that have evaluated vegan diets in pregnancy and in children. While there are some studies on adults the studies that do exist all have significant issues that limit what you can conclude from them.

Anecdotes of people claimed to be "healthy" don't tell you much at all and is riddled with selection bias. After all, you'll find no shortage of people reporting problems on vegan diets as adults, while pregnant and with children. Why ignore these in favor of the positive reports? A clear case of confirmation bias. That is why studies are utterly critical and we lack the studies we need to make meaningful conclusions about vegan diets.

And there are issues with "bringing it together" and you already mentioned them, namely, epigenetics. You won't discover most of these issues until you've observed the 2nd generation into old age. But not only is the sample of older 2nd generation vegans rather tiny, nobody has bothered to study multiple generation vegan families in the first place.

No we don't.
We really only need to know vegan pregnancies are healthy if properly planned, and vegan children on properly planned diets are healthy, etc.

And how do we know whether that is the case? You have to conduct studies that compare vegan pregnancies to a reference population and these studies need to track the various failures that are reported as well. Currently these studies don't exist as such we don't "know" what you're suggesting. You cannot make general conclusions from anecdotes.

We know all of those things; doctors are perfectly capable of assessing the health of their patients without doing some large study.

Except that the methods the doctors use were based on studies. Firstly doctors can only access health to a limited degree and when an issue is discovered a doctor cannot determine whether whether lifestyle factors had anything to do with it unless studies have already show a relationship.

I see this often with vegans, they hold up their blood tests as evidence that vegan diets are working for them. But routine blood tests don't determine your health, they just screen for some health conditions and bio-markers. Ultimately there is really no way to know whether some diet is working well for you, we lack the genetic knowledge to make these determinations. At best we can conduct studies on general populations and look for relationships and use that to guide individual choice.

All that we have. Humans only require nutrients, not particular source of those nutrients, and vegan diets can be planned appropriately to include all of the nutrients humans need.
Dietetic organizations agree. You dismiss the conclusions of professionals because you don't like the conclusions.

"All that we have" doesn't tell me what you have in mind. Saying that "humans only require nutrients" misses all the key issues here. Firstly nutrients have to be absorbed to be useful and there are various issues and genetic variants that impact how people absorb and utilize nutrients. Secondly nutrients are utilized in numerous complex pathways to synthesize the various compounds the body needs and there are a variety of genetic differences in these pathways that can impact how a person responds to a specific diet. And then there are epigenetic issues which we know very little about.

Dietetic organizations are trade groups, they aren't scientific bodies. You obviously have in mind the Academy of Nutrition and Dietetics position paper but that paper is just authored by a few vegetarian authors and isn't endorsed by the Academy or even the reviewers (see the body of the position paper).

Now firstly this is really just an appeal to authority and in this case its a false authority, the Academy of Nutrition isn't a scientific group and has no authority on scientific matters. But the view of the Academy of Nutrition and Dietetics isn't shared by all such groups, for example, the German Nutrition Society has a much less favorable view of vegan diets and doesn't recommend them for children or pregnancy.

And your last comment is just an ad hominem and a bit ironic, unlike vegans I have no ideological barriers that would lead me to believe one way or another on vegan diets.

Skepticism may be, but the margin of reasonable skepticism based on the unknown there is very small. We know from overwhelming epidemiological evidence that less meat is better, so we're comparing the effects of little meat to no meat, and it's not surprising that those differences are going to be small given the small differences in the diets.

That isn't something you can conclude from epidemiological studies, epidemiological studies just tell you about correlations and since there are so many confounding variables in these studies there are no way to isolate variables to help determine cause.

Also "less meat" is vague, health groups have specific guidelines. If you compare the way, for example, Americans are eating compared to dietary guidelines the amount of meat in the diet is by no means the major issue. American women's intake of meat is right around recommended levels and men's intake is higher its not dramatically higher (recommended limit for adult men is 30 oz/week where as average intake is 45 oz). In contrast Americans vastly over consume sugar, refined carbohydrates and have vegetable intakes that are much lower than recommendations. Americans are also eating much less seafood then recommended.

https://health.gov/dietaryguidelines/20 ... figure-2-6

I think the focus vegans point on meat and health is dangerous, it leads people to ignore the most significant issues with western eating patterns today.

[brimstoneSalad]

Its not "that simple" because we lack the research to support such a statement.

You don't need a study to support the obvious; the lack of conflicting evidence is enough for the default conclusion to be that humans can derive nutrition from plant foods. B-12 is the only exception, and that had evidence behind it. If there were other problems, they would have been found just as B-12 was.

For example there are virtually no studies that have evaluated vegan diets in pregnancy and in children.

And yet there are many vegan pregnancies and children; if there was an obvious problem it wouldn't take a study to identify. Practitioners in relevant fields (e.g. dietetics) would have been able to raise red flags.

Very young children should be on breast milk or formula, but beyond that we're talking about typical human digestion and known nutritional needs.
There haven't been studies on digestibility of everything, but there have been enough to know that vegan diets can safely provide needed nutrients.

After all, you'll find no shortage of people reporting problems on vegan diets as adults, while pregnant and with children.

I'm sure there are as with anybody. The fact is that populations of vegans have been studied, so you have to rely on special pleading claiming a survivorship bias to ignore those studies as self selected when there's no reason to believe they are.

When populations adopt a diet for ethical or religious reasons rather than for purposes of chasing optimal health there's little reason to believe there's a survivorship bias at play. It didn't stop people from being afflicted with B-12 deficiency and it didn't stop that from being discovered.

In order to hide, such an effect would have to be both rare and *very* subtle and not very harmful.

Why ignore these in favor of the positive reports?

I don't. I think I've asked before: show me a single case study of a vegan having problems while under the direction of a dietitian and attempting to resolve the problems and failing.

The fact is that if these cases are as abundant as you claim they are, there'd be significant credible evidence in the form of case studies.

Like with trying to find bigfoot: you can pretend that the evidence is hiding or systemically ignored by a grand conspiracy, or you can recognize that absence of evidence when there really SHOULD be evidence IS evidence of absence.

A clear case of confirmation bias.

No, it's a clear case of trusting professionals and not being a conspiracy theorist who has an axe to grind.

That is why studies are utterly critical and we lack the studies we need to make meaningful conclusions about vegan diets.

I don't believe there's any number of quality of studies you would actually accept. Just like the cryptobiologists who will always believe in bigfoot or the Loch Ness monster, because they'll keep moving the goal posts and making excuses for why the search turned up nothing.

If you're committed to believing that a vegan diet just doesn't work for a large swath of the population, you'll believe that and there's nothing I can say to talk you out of it.

And there are issues with "bringing it together" and you already mentioned them, namely, epigenetics.

Yes, I mentioned it to call it absurd.
There are also issues with finding bigfoot, because they can phase shift and become invisible to all of our equipment.

Enjoy your sci-fi excuses, I'm sure you will never run out of them. Although I don't think you've thought this particular rationalization through.

There's no reason to believe there would be deleterious epigenetic effects from a vegan diet on the second generation; more likely epigenetic adaptations would do the exact opposite and make children of vegans more able to be vegan. Shifts between more meat and more plants were common in ancient man and earlier, and epigenetic dietary adaptations evolved to account for that and improve health, not worsen it.

The fact that first generation vegans can do well should indicate that second generation vegans would only do even better.

You won't discover most of these issues until you've observed the 2nd generation into old age.

How convenient for you. So we need to start a study now, and in 100 YEARS you might be convinced.
Basically the definition of an unfalsifiable claim. We couldn't even achieve the ridiculous standard of evidence you demand in our lifetimes.

Fortunately, we don't need to because that's an absolutely ridiculous demand.

You cannot make general conclusions from anecdotes.

You can make general conclusions about what is very unlikely based on a lack of evidence that should have been there.

We can reason that properly planned veganism with B-12 is safe and that bigfoot doesn't exist, because credible evidence to the contrary should be abundant if those things were not the case.

Firstly doctors can only access health to a limited degree and when an issue is discovered a doctor cannot determine whether whether lifestyle factors had anything to do with it unless studies have already show a relationship.

If somebody is low in a mineral like iron doctors do not hesitate to question diet.
The most likely issues are all easy to diagnose and to relate back to diet if it's a problem.

Ultimately there is really no way to know whether some diet is working well for you,

If people can't even tell, then what do you think "working well" is?
Do you think longevity is being magically affected without any health or disease risk biomarkers?
And why would you imply that being vegan is more likely to shorten life than lengthen it when all the mechanistic evidence we have suggests otherwise (likely lower BMI, more fiber, more antioxidants, lower cardiovascular risk factors)?

we lack the genetic knowledge to make these determinations.

If you don't know, then you're making a bet; even if a tiny fraction of the population has lower longevity as vegans without any indication of that on tests (very unlikely), on average it's reasonable to believe your odds are better going vegan.

Firstly nutrients have to be absorbed to be useful and there are various issues and genetic variants that impact how people absorb and utilize nutrients.

There are, but they aren't that dramatic. That's why recommendations have a safety margin on them to cover the majority of the population. It's not hard to add another margin on top of that if you're worried.
There have also been studies on nutrient absorption which show adaptability, and AFAIK no indication of such dramatic genetic differences there.
Small differences are easy to compensate for.

Secondly nutrients are utilized in numerous complex pathways to synthesize the various compounds the body needs and there are a variety of genetic differences in these pathways that can impact how a person responds to a specific diet.

Beyond digestion and absorption, we have large amounts of information which is in no way subject to self selection or survivorship: TPN.
https://en.wikipedia.org/wiki/Parenteral_nutrition

So that's just silly to say we don't know what people need. You'll probably complain about different activity levels, but not all people on TPN are immobile.

And then there are epigenetic issues which we know very little about.

What we do know about them only improves the prospects for digestion and absorption of nutrients on a vegan diet.

Dietetic organizations are trade groups, they aren't scientific bodies.

This has been discussed before.
These are working professionals with educations in the sciences; they are qualified to interpret the data and come to credible conclusions and if there were issues they would be known. Like how bigfoot would have been spotted.

But the view of the Academy of Nutrition and Dietetics isn't shared by all such groups, for example, the German Nutrition Society has a much less favorable view of vegan diets and doesn't recommend them for children or pregnancy.

One outlier among many such groups, and there are reasons why their recommendations are different and those are specific to the German population and food availability.

wiki/index.php/Adequate_Nutrition

Critics may also Cherry-pick the DGE (German Nutrition Society) which released a more critically worded 2016 position paper[3], ignoring the fact that the recommendations are focused on sensitive groups within the context of German culture and food availability: for example, in Germany (due to ill-conceived EU regulations on organic labeling) the overwhelming majority of vegan substitutes like plant milks are not properly fortified with well studied vitamins and minerals, but with unusual forms of plant extracts (See discussion in comments[4]). The position does not state that a vegan diet is inherently inadequate or unhealthy, and to the contrary outlines specifically HOW to get the necessary nutrients in table 2: Potential critical nutrients in a vegan diet and vegetable nutrient sources. The general sentiment of the position paper is that they do not believe that people are competent, and it is necessary that fortified foods and vegan specialty foods and supplements be more reliable and widely available to reduce risk of inadequate nutritional status on a population level. The tendency of German vegans to favor organic and want to avoid all supplements seems also to be a major concern.

unlike vegans I have no ideological barriers that would lead me to believe one way or another on vegan diets.

You eat meat: that's a very powerful bias whether you want to admit it or not. You don't want to believe you're wrong for doing so, and you spend a lot of time rationalizing your choices and fear mongering against vegans. You've also expressed some kind of aesthetic infatuation with pastoralism, which is another bias.

I think the focus vegans point on meat and health is dangerous, it leads people to ignore the most significant issues with western eating patterns today.

If you want to campaign against processed sugar that's fine; it doesn't mean you have to shit on veganism or fear monger to scare people away from giving up meat.
A lot of vegans are well aware and caution against processed sugars too. On this very forum we spend a fair amount of time discussing lower carb vegan diets and how to avoid excess sugars.

[carnap]

You don't need a study to support the obvious; the lack of conflicting evidence is enough for the default conclusion to be that humans can derive nutrition from plant foods.

This isn't how science works, there isn't a "default conclusion". The default is skepticism, that is, you withhold judgement until there is sufficient evidence to support a given hypothesis. Throughout history many beliefs people thought were "obvious" have been shown wrong when they were studied rigorously.

And yet there are many vegan pregnancies and children; if there was an obvious problem it wouldn't take a study to identify. Practitioners in relevant fields (e.g. dietetics) would have been able to raise red flags.

Yes, if there was an "obvious problem" it would likely have been already identified but "obvious problems" aren't the only issues that occur. For example just take drug trials, "obvious problems" are usually detected quickly but subtle problems can take decades to discover and many drugs have been pulled from the market despite looking fine from early trials.

But in this case you're not even referring to preliminary research but instead anecdotes. Even "obvious problems" can be hard to find by just looking at anecdotes because they are subject to strong selection bias.

There haven't been studies on digestibility of everything, but there have been enough to know that vegan diets can safely provide needed nutrients.

There is no way to conclude that given the gaps in research and its not scientists that would make such a bombastic statement.

Also the way you're speaking about this ignores what is likely the key issue here, namely, how specific genetic profiles respond to vegan diets. The digestibility of a specific nutrient isn't fixed among all people, on the contrary, it various based on their specific genes. As such even if vegan diets work fine for some group of people, it doesn't mean they will work for everyone. To determine that you need to conduct studies that lack obvious suvivorship bias and so far we don't have those studies on vegan diets.

But you mentioned breast milk and formula earlier and I think that is a perfect example to illustrate the issues here. On paper formula contains all the nutrients infants require and infants do typically survive while consuming it.....yet they aren't as healthy as breast-fed infants. They suffer more health issues, they appear to have lower IQs, they suffer higher rates of SIDS and a variety of other issues. Of course anecdotes of "healthy formula fed infants" doesn't tell us about any of this, you have to do comparative studies.

The fact is that populations of vegans have been studied, so you have to rely on special pleading claiming a survivorship bias to ignore those studies as self selected when there's no reason to believe they are.

There are studies on adult vegans but the studies suffer from significant flaws because they are mostly conducted by looking at existing data sets but these data sets weren't designed with studying vegan diets in mind.

And there is every reason to believe the studies suffer from survivorship bias, but it has nothing to do with self-selection. Instead that when you do an observational study you're only studying the people that are still vegan and as such you're only studying the current "survivors" of the diet. If a sub-population of people had difficulty with vegan diets they would be largely missing from the study because they would have largely already given up the diet. You need to study the design to specifically deal with this issue.

And you really think someone that starts a vegan diet for ethical reasons is likely to continue the diet after they start having health issues? That is probably the most compelling reason they would stop and we know many of them do, in fact, stop.

The fact is that if these cases are as abundant as you claim they are, there'd be significant credible evidence in the form of case studies.

Why is that? There is a lack of case studies on vegans as a whole because its a small dietary group.

No, it's a clear case of trusting professionals and not being a conspiracy theorist who has an axe to grind.

Except I haven't referred to any conspiracy theories and you're holding up the view of one group and discounting the other despite the fact that the two groups have similar "authority". In any case, its not accurate to say that all dietetics groups think vegan diets are appropriate for everyone, groups in Europe are generally more hostile to vegan diets than Northern American groups.

If you're committed to believing that a vegan diet just doesn't work for a large swath of the population, you'll believe that and there's nothing I can say to talk you out of it.

I reckon that may be true....but I'm by no means committed to such a belief. This is just something you keep repeating to attack me which I find ironic because, in fact, its vegans that are committed to a particular belief here.

Yes, I mentioned it to call it absurd.

Yep and yet there is nothing absurd about it. There are documented lifestyle factors that result in epigenetic changes in the 2nd and 3rd generation. Also I've never claimed that there are "likely" to be deleterious epigenetic effects from a vegan diet but rather that we cannot know whether this is the case until studies are conducted.

If people can't even tell, then what do you think "working well" is?
Do you think longevity is being magically affected without any health or disease risk biomarkers?

You like to talk about magic a lot, but magic has nothing to do with it. We don't have good bio-markers that can predict longevity and there is no test you can take that will tell you whether you're "healthy" or not.

But there are a variety of things you can consider. You can look at your blood work, you can look at your family and ethnic history, you can look at general dietary guidelines and so on. But at the end of the day you just have crude approximations so you really don't know whether diet X is "working for you" or whether diet Y would have been better.

Though from my experience, when people are committed to a diet they find ways to ignore objective measures. I see that all the time with vegans, paleo, keto, etc folks.

There are, but they aren't that dramatic. That's why recommendations have a safety margin on them to cover the majority of the population. It's not hard to add another margin on top of that if you're worried.

The RDA for nutrients were all determined by looking at omnivorous populations, its very likely the RDA are different for vegans but we don't know because the studies haven't been conducted. Some vegan health professionals do recommend just increasing the intake in some cases (such as for iron, zinc and protein) but that is really just guess work.

But just "adding another margin" isn't so simple, some nutrients are hard to source on vegan diets so doing that will start to require supplementation but supplementation can come with health risks. Even B-12 supplementation, despite being a water soluble vitamin, has some associated health issues for some people (e.g., promoting acne in a sub-population).

You eat meat: that's a very powerful bias whether you want to admit it or not. You don't want to believe you're wrong for doing so, and you spend a lot of time rationalizing your choices and fear mongering against vegans.

Why would the mere act of eating meat result in a powerful bias against the feasibility of vegan diets? Agreeing that vegan diets are feasible doesn't obligate one to adhere to the diet. On the other hand vegans have an obvious ideological commitment which is why I think your comments are ironic. But its also just an ad hominem.