Vegan? It’s More Than Vitamin B12 And Zinc That’re At Risk


8 Min Read

Vegetarian and vegan eating is more popular than ever before for a variety of reasons. This post isn’t about delving into the many reasons why a person might choose this dietary pattern nor is it about splitting hairs over the different ways ‘vegetarianism’ shows up, i.e. no red meat, but yes to eggs & dairy, or no land animals but yes to fish, or ‘flexitarian’ where someone is a ‘sometimes’ vegetarian; a term I loathe. To me, if you eat animal-based foods regardless how often, then you’re not a vegetarian; it’s about a preference but I digress.

I’m going to go beyond some of the more popular nutrients of concern when it comes to being vegan although the usual suspects still stand: vitamin B12, calcium, zinc, iron, vitamin A, and the long chain omega-3 fats EPA & DHA [as opposed to the shorter chain alpha-linolenic acid or ALA, which is not the same as EPA & DHA].

I’m not suggesting that diets which contain animal foods are necessarily healthier but studies show vegetarian and vegan diet need more attention when it comes to certain nutrients. Why? Because philosophies aside, animal foods tend to contain these nutrients in higher amounts and, more importantly, those nutrients are absorbed better/more efficiently.

Nutrients of concern when it comes to vegan diets

Vitamin B12: Vitamin B12 by far the best understood nutrient at risk for vegans. B12 is so crucial for so many physiological functions. There are virtually no vegan sources of B12 which is found abundantly in animal foods. B12 plays an important role in mental health and in preserving cognition as we age. Several studies have confirmed how vegans are at risk for B12 deficiencies and this is especially true for children’s growing brains while following a vegan diet. (12,). Vegans need to be sure to include foods fortified with vitamin B12, use Brewer’s & nutritional yeast and/or supplements.

Signs of impaired cognitive function in adolescents with marginal B12 status

Zinc: Suboptimal intakes of zinc is common, even for omnivores but more so for vegans, Like all minerals, zinc from plant foods isn’t absorbed as efficiently because of anti-nutrients like phytic acid, fiber, saponins etc. Some research puts the decreased absorption at 35% less in a vegan diet and it’s estimated that zinc requirements may be as high as 50% greater for vegetarians due to the lowered absorption.

Bioavailability of iron, zinc, and other trace minerals from vegetarian diets.

Note, it’s not just zinc where requirements are estimated to be higher in vegan diets, it also goes for protein, iron, calcium, and magnesium.

Iron: Iron is found naturally in some plant foods but the reality is, it’s not absorbed as efficiently as it is from animal foods – sorry folks, it’s not a matter of opinion, it’s a matter of fact. It is for this reason that vegans tend to have lower body stores of iron. (67). Like B12, vegans are advised to look for iron-fortified foods, and/or take supplements. Eating acidic or foods rich in vitamin C at meals can modestly increase the amount of iron absorbed from plant foods.

Omega-3 fats EPA & DHA: In the world of omega-3 fats, people routinely use those derived from animals foods (fish, seafood & fortified eggs) interchangeably with those from plant foods [walnuts, canola, flax, chia]. Nothing could be more dangerous. Like siblings from the same parent who share a name, they are not the same nor do they behave the same physiologically speaking. Vegans tend to have an excess of the plant-based omega-3 fat alpha-linolenic acid or ALA at the expense of EPA & DHA. This why there’s be a growing market for vegan sources [algae] of EPA & DHA to help fill the gap and to ensure vegans get these precious omega-3 fats. One of my favourite products is NutraVeg by Ascenta Health. One servings provides 400 mg of DHA & the equivalent of about 165 mg EPA.

Vitamins A & D: Beta carotene is not vitamin A which is called retinal/retinol. Preformed vitamin A is only found in animal foods like milk, liver, fish & seafood, organ meats and eggs. It’s true a small amount of beta carotene from orange/green vegetables and orange fruit is converted to vitamin A, the amount is small (8) and not everyone does it to the same degree; some of us convert more than others do. To get the same amount of vitamin A from 1/2 teaspoon of cod liver oil, you’d have to eat 2 cups of carrots, 1 cup of sweet potatoes, and 2 cups of kale – good luck.

Vitamin D typically comes from the sun but is also found in eggs, organ meats, fortified milk and fish. A little vitamin D is found in some mushrooms but consumption remains low which is why vegans typically have 74% lower blood levels of vitamin D compared to omnivores (9) although both vegans and omnivores don’t get enough of this critical vitamin but that’s a different story. For a brief overview, read my post A Primer on Vitamin D.

Choline: A cousin to the B vitamins, choline is a much underappreciated nutrient. See my full post on choline here. It is found in plant foods but like most of the other nutrients in this post, choline is not only found easily in animal foods, it is absorbed well too. Best food sources are liver, egg, fish, milk, turkey, chicken & seafood. Choline is needed for cognition, memory consolidation, and learning and for fetal brain development.

Creatine & carnosine: Creatine is not just for body builders, it’s a form of stored energy for everyone as well. Studies routinely find vegetarians and vegans to deficient in creatine which essentially starves muscles and has detrimental effects on cognition (1011 12). Carnosine is type of protein (dipeptide; 2 amino acids) concentrated in the brain and muscles. It’s a powerful antioxidant, and helps to prevent some of the negative effects of degenerative diseases like diabetes, cardiovascular disease, and more. Like creatine, carnosine is only found in animal foods (13).

Methionine: It is an essential amino acids meaning that the diet must provide it unlike other amino acids which the body can produce on its own. Methionine is low in plant foods unlike animal foods. Most fruits and vegetables contain very little of it and most pulses [chickpeas, lentils, dried peas & beans] are also low in methionine. Soy is a good source but it would require consuming several servings of soy per day to get what you could from small amounts of animal foods. Most vegans rely on fortified vegan protein powders and shakes to get the methionine they need.

Leucine: Leucine is a unique essential amino acid. Leucine is one of the 3 branched chain amino acids [pictured above] that play a vital role in muscle protein synthesis, repair and maintenance. The latest & best research shows that to reap the benefits that protein has to offer on maintaining muscle mass, especially as we age, we need to get about 10 g of leucine at each meal which is easily accomplished when a variety of proteins are eat together, both plant and animal [hint for a total protein content of 30 g per meal]. The reality is, animal foods are abundant in leucine which means they can deliver lots of leucine on their own or, if eaten in smaller serving sizes, can bump up the modest amounts of leucine in plant foods. Manufacturers of vegan foods like meal replacements & protein powders know this which is why many have added extra branched chain amino acids to their products so that they resemble & approximate animal based foods and protein powders – go figure.

Bottom Line

To be clear on my bias, it is my personal and professional opinion, that vegan diets are not the best for human health. Whereas vegetarian diets that include some kind of animal product like fish, egg or dairy, will easily eliminate the nutritional concerns of a vegan diet, vegan diets need to be given extra care and attention. There’s a reason why there’s never been a vegan society/culture in human history unless I am proven otherwise. That’s because precious sources of food, like animals, would have never been passed up. Even Buddhist monks will eat eggs and dairy. As such, the human body evolved within the context of different diets that provided the unique nutrients found in animal foods allowing the human race to thrive. Of course my role as a dietitian and nutritionist would be to help anyone who wants to follow a vegan diet ensure they are getting the nutrients they need in a manner that fits their philosophy.

I don’t believe that it’s possible in the long term to meet our nutrient needs in a way that propels us to optimal health [well into our 70s and beyond] on a vegan diet without the use supplements. The reality is, vegans struggle to get enough B12, zinc, iron, calcium, choline, vitamins A & D3, and omega-3 fats EPA and DHA [not to mention choline and the others] in amounts that are easily absorbed by the body. This is especially true for children.


Doug Cook

I am a Registered Dietitian & Integrative & Functional Nutritionist and former Certified Diabetes Educator with over 15 years of clinical nutrition experience. I practice a holistic and integrative approach providing science-based guidance on food and diet along with nutritional supplements where appropriate. My strength lies in my ability to explain complicated nutrition and scientific concepts in plain language which I then put into everyday practical dietary advice. I have a unique approach to nutrition counselling. I have the solid education & training of a dietitian but know that there are many points of views outside this model, and I incorporate them into my practice.

Doug Cook

I am a Registered Dietitian & Integrative & Functional Nutritionist and former Certified Diabetes Educator with over 15 years of clinical nutrition experience. I practice a holistic and integrative approach providing science-based guidance on food and diet along with nutritional supplements where appropriate. My strength lies in my ability to explain complicated nutrition and scientific concepts in plain language which I then put into everyday practical dietary advice. I have a unique approach to nutrition counselling. I have the solid education & training of a dietitian but know that there are many points of views outside this model, and I incorporate them into my practice.

Post a Comment
Alicja Sakowska
Alicja Sakowska 5pts

We were designed perfectly! Our bodies don't need longer colons my dear. Nature is beautiful!

Sharon Smalley Santello
Sharon Smalley Santello 5pts

Our digestive tracts are much longer than our meat eating counterparts who have much shorter colons. There's your nature!

Anab Issa Abdulkarim
Anab Issa Abdulkarim 5pts

I have been a Vegan for 3 years and my blood analysis has never shown any deficiency and I feel great! Maybe you state other facts/reasons/studies other than nutrition because clearly you are wrong.

Lynn Thomas
Lynn Thomas 5pts

I eat REAL food (vegetables, fruit, meat, fish, bread), in moderation...that is all.

Barbara Janzig Bankes
Barbara Janzig Bankes 5pts

I don't buy all this. If meat is out of the diet, there isn't a need for some of the levels of some of the nutrients mentioned here. Most people do not get enough sun and need Vit. D3 supplements. Long term studies have shown that vegetarians who eat right live longer than meat eaters. Vegan cuts out only dairy beyond the vegetarian diet. There are plenty fruits, vegetables, seeds, nuts, legumes, etc. for a healthful diet. Just add B12. Calcium, mag, zinc, copper tablets take care of those along with the foods, Cheerios are a salty multivitamen source of iron. What is important is to eat a well rounded and balanced diet. Without meat and dairy there are plenty of calories left for good, high-nutrient vegetarian food.

Alicja Sakowska
Alicja Sakowska 5pts

We were given canine teeth for a reason, you can't fight nature.

Anthony Woo
Anthony Woo 5pts

Rudra Ayurveda Center New York1 W 34th St #702, New York, NY 10001 (212) 473-1127

Peter Parviz Beizaee
Peter Parviz Beizaee 5pts

You should try the products that Par's Natural Foods makes. the best Vegan and Gluten Free Products While the best taste is in mined too!

LaurieConrad 5pts

Interesting however my whole family is vegan, for years, and we only take vitamin B-12 on occasion.  We range in age from 22 to 67 and all of us are in perfect health.  We get regular yearly physical exams, blood tested, bone density, you name it.  We are in perfect health.  So if a plant based diet isn't as healthy, then why do I have friends the same age as me already taking medications for things such as type II Diabetes, high blood pressure, high cholesterol and why have some of my friends had breast cancer, brain cancer?  They eat the standard diet and we do not.  So it may be your opinion, but it is not my, or my family's, or my friends who are also vegan (a group of about 40 of us - we are all healthy) experience.  

Melissa Dalby
Melissa Dalby 5pts

I practice this diet and know that I'm getting the right rda.

MariahCasey 5pts

As recorded in the Bible, faithful mankind strictly ate plants before The Great Flood of Noah's day. The average age was over 600 years I believe, which declined after The Great Flood. This was probably mainly due to the loss of the vapor canopy enveloping the Earth but meat consumption may also be a factor.

Maureen Fougère
Maureen Fougère 5pts

Boo. I'm all for sharing information but to say that vegans can't live healthily for very long is complete garbage. Like everyone else we have to make sure we eat a wide variety to meet our nutritional requirements, but since when do you see long term vegans going around with all kinds of ailments like most of society? As a vegan for 10 years, I've never felt healthier and I can sleep easy knowing I don't contribute to the brutality that are the egg and dairy industries.

Kevin O'Neill
Kevin O'Neill 5pts

Gracias primita. :) No sé si crees que el veganismo (minimizar la violencia a todo lo que siente) es un deber. Sin embargo te apoyo en tu camino para reducir porque eso es mucho mejor que hacer nada. Estoy convencido que si sigues en ese camino sera mas facil ver la realidad de como tratamos los animales y nuestros deberes corespondientes. Animos primita. :)

Alexandra Volkert Gallen
Alexandra Volkert Gallen 5pts

Muy interesante ☺️ no soy vegan or vegetarian pero si tomo hierro (Iron), folic acid y vitamina B12. Tengo tendencia a estar baja en iron. Admiro mucho tu amor por los animales y como vives tu vida comiendo tan sano. Aun no estoy lista ni para ser vegetariana pero quiza algun dia. Como muy poca carne y pollo pero me encanta el pescado.

Kevin O'Neill
Kevin O'Neill 5pts

Alexandra Volkert Gallen Primita me alegra mucho que estas lleendo sobre esta tema! :)Creo que la pregunta relevante no es si siempre es CONVENIENTE ser un vegano saludable, la pregunta es si es POSIBLE.El autor escribe ''I don’t believe that it’s possible in the long term to meet our nutrient needs in a way that propels us to optimal health [well into our 70s and beyond] on a vegan diet without the use supplements.''La foto abajo es de Jim Morris. El se volvio vegano porque queria competir en el culturismo a su edad y sabia que no lo podria lograr dependiendose de la proteina animal.Cuando el autor habla de la necesidad de 'suplementos' (plural), cualquier persona que conoce esta tema sabe que se esta referiendo al B12. Salvo la vitamina D que conseguimos a traves del sol, todos los nutrientes demas podemos conseguir en cantidades optimas comiendo una variedad de alimentos veganos.Salvo en las granjas organicas, La tierra que usamos para crecer nuestra comida no contiene la bacteria necesaria para producir B12. Por eso damos supplementos de B12 al ganado con el fin de absorber esos supplementos tras comerlos.Si queremos vivir 'natural' sin ningun supplemento hay dos opciones: 1)Podemos comer animales organicas o salvajes 2)Podemos comer las plantas que esos animales comen sin lavar toda la tierra (el b12)Esas dos opciones son 'naturales' pero solo una no causa la muerte inecesaria de un ser sintiente.Si comer tierra organica no te parece muy atractivo, hay otra opcion no dañino que la gente puede tomar. Eso es tomar un suplemento.Enfin, Hay una opcion B12 saludable para veganos que quieren ser 'naturales', y otra para los que quieren ser practicos.Aunque es para nada complicado ser un vegano sano, termino repitiendo que la pregunta no es si siempre es CONVENIENTE, la pregunta es si es POSIBLE. No estoy hablando de fulano en antartida que tiene que cazar focas para sobrevivir. Estoy hablando de nosotros que tenemos supermercados, que no tenemos que causar ese nivel de muerte y sufrimiento.Un beso. :)

VinodKumarPillai 5pts

This is called TALKING and TALKING without MEANING and SENSE.

Finally what is your conclusion? You sound to be highly opinionated.

You need to first identify yourself as a Dietitian rather than a Ayurveda Practitioner.

It is not necessary that you know both ideologies. I would say, you have a lot to learn in Ayurveda for sure ( leave alone human being )

Half Baked knowledge of Ayurveda will only bring bad name to it.

I would say at least half of India is Vegetarian if not more. Some communities like Jains are purely Vegetarians.

You guys consider human beings only as physical body. Adding and subtracting minerals and nutrients seems to the the body for you. 

The only good news for you is, YOU HAVE A LOT TO LEARN on the types of food and Doshas and their relationship.


Simone Bender
Simone Bender 5pts

b12 can be found in nutritional yeast... We use it in our diet abundantly. Molasses has also many minerals needed . Animal proteins and products are not ideal for the human body and I would like to know where the research came from associated with this article ?

Bhawani Singh
Bhawani Singh 5pts

In the name of Ayurveda you're advocating non veg food? The first principle of Ayurveda is non violence.I'm out of this site. I strongly object to this article.

Ayurveda 5pts

Kimberly Balbach You're welcome! :)

Alphonsa Plackattu
Alphonsa Plackattu 5pts

Chemicals and pesticides, preservatibes , GMOs are destroying it real benefits of god given gifts.

Ruchir Bakshi
Ruchir Bakshi 5pts

This post had me at "that're"... Wait. Never mind.

Chels Cookson
Chels Cookson 5pts

An article of this content is much better when the writer is more subjective and not bias to one side.

ManjuLa Katikam
ManjuLa Katikam 5pts

More research needs to be done by the nutritionist who has written the content. Honest suggestion !

ManjuLa Katikam
ManjuLa Katikam 5pts

Such an ignorant post . Did not expect it from this page. \U0001f611

AviJain 5pts

Problem with this article is how it addresses the audience. It would be more constructive if it addresses the question without drawing conclusion: "how to address any kind of nutrition deficiency when you are vegetarian or vegan". 

Fact is that irrespective of the diet, almost all people with age starts getting deficient in some nutrient or other. Human body is ultimately not a perfect machine. It falters! I know so many people having supplements for some or the other reason, logical or illogical. No one judges them. But if you are vegan, it is presumed that your deficiency has to do with vegan "diet" which creates this rift and defensiveness and not a productive discussion. 

Given how small a fraction of people are vegans and of these there is significant percentage of raw vegans, I don't think there is any substantial data or evidence to indicate it is the "vegan" diet that is causing the problem. Further what is vegan diet? It is as if every vegan person every morning to late night eats kale and greens like that? It really needs control variables to help understand and narrow down what kind of vegan diets are causing a problem if any. Experience helps you determine control variables and only data helps you determine the root cause! 

While author maybe technically correct no society has been vegan in human history (after all veganism is a concept less than 100 years old), many vegetarian societies would add only milk to what is currently considered vegans. But while milk was acceptable, it was rare. Many people in India would hardly have access to milk which was more of a status symbol than a staple. Staple throughout the country has been lentil and wheat or lentil and rice. So has been the case in Africa and in Latin America (bean and rice!). Frankly meat and milk as reliable source of nutrition for masses is basically a modern concept coming from systematic animal exploitation that is called factory farming which has resulted in emergence of veganism.

In my case, I was told my iron was low when I was NOT a vegan (thank God otherwise people would blame it on "vegan diet"!). It has only been 2+ years, and it hasn't changed. No indicators of any other nutrition deficiency. Really the best way is to have periodic physical exam, keep judgement at bay and if there is deficiency address it with sources in hand! It is as much true for vegans as for non-vegans!

Heather Duro
Heather Duro 5pts

I do agree..and to add most vegans have a poor diet. A vegan needs to have like you said a well rounded diet. Imho animals are not a food source..but thats another conversation :)