Doctor's Note

What nutrients could vegans be deficient in?

Even if we’re consuming calcium, are we absorbing enough? Learn more in these videos:

For some context, please check out my associated blog post: Poultry Paunch: Meat & Weight Gain.

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  • Michael Greger M.D.

    Please feel free to post any ask-the-doctor type questions here in the comments section and I’d be happy to try to answer them. And check out the other videos on omnivores. Also, there are 1,449 other subjects covered in the rest of my videos–please feel free to explore them as well!

    • Dr. Greger, is there a study cited for the deficiencies mentioned at the beginning of the video?

    • I’m also trying to locate the source of the study referenced at the beginning of the video (i.e. regarding the different deficiencies in the different diets; do you have a reference for that handy, Dr. Greger?

    • I see that there is other activity in this forum from the NF Team, so I thought I might re-ping on this issue. I’ve been including a link to this video in many of my activism efforts supporting a plant based lifestyle, and I’m occasionally questioned on the source of this study (i.e. regarding the different deficiencies in the different diets). I’ve tried to discover it on my own, but have been unsuccessful.

      Throw me a vegan-bone here? =o)

  • Toxins

    Where is the study showing the nutrient deficiencies in the omnivores? I dont doubt they have it as of what they don’t eat but I am trying to gather data in my own personal collection.

  • Kush Patel

    Do you have any study on Lacto vegetarianism and Nutrient Deficiencies 

  • Thea

    This is one of my favorite videos.  The part that is most interesting is the comparison of vegan deficiencies to omnivore.  Like the others, I too am interested in a citation for the study showing the comparative deficiencies of the different diets.  I’m posting here so that I will get an e-mail when the “sources cited” section is added to.  Thanks!

  • David H

    How can we get enough calcium in our diet apart from consuming fortified soy milk?

    • Toxins

      If you are eating lots of greens and beans you will be getting plenty of calcium.

      • mbglife

        I eat a lot of beans and lentils, sometimes cooked from scratch, but often from canned. I noticed on the side of the cans for different brands of beans it says that a serving is only 4% or 6% of the RDA of calcium. I love beans, but not even I could eat enough to get to 100%. I don’t understand the disconnect between the message, which I have heard for years, that beans are high in calcium and the label, which indicates that they are not. Some peg the RDA as low as 2%. Any insight into this discrepancy?

        • Toxins

          The RDA for calcium is set quite high, at 1000 mg. If we achieve 600 mg we will have plenty of calcium and even less then these amounts, between 300-500 will be fine. No matter how much calcium you eat, osteoporosis prevention is highly dependent upon exercise, low sodium intake, low animal protein and adequate vitamin d and k levels. “Under the extreme condition of immobilization, rapid bone loss occurs despite consumption of 1,000 mg (25 mmol)/day of calcium”

          With this in mind, we can boost the RDA for our own needs. We can double the percentages. So although a cup of black beans may only have 5% of the USDA assigned RDA, it will have 10% of our RDA. A cup of cooked kidney beans will have 24% of our RDA, A cup of cooked collards will have 52% of our RDA. If one consumes a high salt, high animal protein diet then these calcium RDA levels should be increased because the body now requires more calcium.

          • mbglife

            Toxins: Thanks for the helpful info and the links. I have used that site for years and find it helpful. Another fantastic site, with some narrative and recipes, is the Worlds Healthiest Foods. Just enter the food you’re looking for in the upper righthand corner search box and you’ll get tons of information on it.

    • mag

      Meat and diary tends to leech nutrients off your bones. If you look at nutritional values of veggies you see almost all have some of it. And since you consume mostly veggies in your diet you get enough. Meat has way too much protein for our body to process it. Want more info read everything by Dr Barnard or Dr Campbell. They described all kind of researches involving nutrition

      • Gary

        Dr. Gregor has a video with some recent studies that challenge that theory. Plenty of other reasons, though, to avoid meat and dairy.

  • Roy

    Are we anatomically and physiologically omnivores or herbivores?

    • Hi Roy, We are herbivores designed as hind gut fermenters who differ from the great apes in two respects… we have about 4x the volume in our small intestines to aid the intake of starches and we have 3-9X the amount of amylase genes to aid the digestion of starches. Animals who digest plants need adaptions to their intestines as it is harder to digest plants.. they are longer and either modify the fore gut with more than one stomach or the hind gut with modified caecum and/or colon as we have. Of course all of our other anatomical features are consistent with non hunters from our jaws and teeth to the location of our sexual organs… have you ever seen a predator with the sexual organs in the front of their bodies? Be well.

      • Chris Winn

        Have you ever seen a predator use a spear though? Point is I’m not sure the sexual organs at the front of the bodies thing is an actual point. Also, don’t we have pores all over our bodies so we can run antelopes to their death, no spear even needed?

    • Ashish

      Are Humans Designed To Eat Meat?

  • georgina08*

    Hi i am from Australia and i am studying the “healths benefits of a vegan diet for teenagers” for my year 12 research project and struggling to find information. I was wondering if you could help me out please.

    • Scour this site. It has hundreds of videos with hundreds of sources cited.

      • georgina08*

        I have looked but cant find any useful ones if you have any useful ones that would great if you could tell me them

    • barbarabrussels

      Perhaps you could try typing mood or acne in the search box above ;-)

    • Magda

      google anything by neal barnard,, dro campbell. If you can get their books it will be great. WIll help you a lot. from there you can find different resources

  • Nicole Duca

    I have heard that Vegans are also deficient in vitamin A. Is that true and if so what is the best supplement?

    • Kevin

      I know I’m a bit late, but that seems nearly impossible. Half of one medium carrot will give you more than 100% of your RDA. Some leafy greens like kale will also give you more than 100%. Sweet potatoes have nearly 400% per potato. I’d expect a beta carotene overload, like carotenemia instead of a deficiency.

  • Lin

    Dr.Greger, what about this info though?
    Dr.McDougall: As long ago as 1978 Paterson wrote in the Postgraduate Medical Journal, “Many official bodies give advice on desirable intakes of calcium but no clear evidence of a calcium deficiency disease in otherwise normal people has ever been given. In Western countries the usual calcium intake is of the order of 800-1000 mg/day; in many developing countries figures of 300-500 mg/day are found. There is no evidence that people with such a low intake have any problems with bones or teeth. It seems likely that normal people can adapt to have a normal calcium balance on calcium intakes as low as 150-200 mg/day and that this adaptation is sufficient even in pregnancy and lactation.

  • FreeAmerica123

    Dr. Greger, I am looking for information from scholarly journals on the topic of: “Are vegan diets safe for children. I am not finding much of anything that says yes or no. Could you please assist me in finding some journals or where I might look for something other than abstract that I do not have to purchase to get this information? I need 6 journals, (3-pro 3-con). Thank You for your assistance.

  • SopranoNatasha

    Dr. Greger, thank you for this wonderful site! I’m enjoying doing diligent research for how best to feed my 7month old and our new family :-) I wish her pediatrician was more knowledgable about plant based nutrition. How do I respond to his concern that there isn’t enough bioavailability of vitamins/nutrients in plants to meet her needs? He specifically mentioned D (she takes D drops), iron and vitamin K. He admitted that we probably know more about this than he does (ha!) but seemed adamant that she would need powdered supplements? He wants to do regular blood work to check her levels. How do I best address his concerns and sound like I know what I’m talking about?

    • Thea

      SopranoNatasha: I recommend taking a look at the following page. This page is from VRG, the Vegetarian Research Group. VRG is well-respected and well-researched. At the bottom of pages from the articles references in the page below, are references to the original research.

      I have only looked at, Feeding Vegan Kids. It was super-good and I highly recommend it. The other articles may also be good.

      I hope this helps.

      • SopranoNatasha

        Thank you, Thea!

  • Joel Adams

    This is a great video to refer people too when they go on about how becoming vegan is so dangerous. However, I, like many others would like to know the source of this study as Google is being no help.

  • uv

    To those interested in the original sources of the studies about vegan deficiencies vs. omnivore deficiencies, I found an internet forum which copied/pasted an article on this topic. The source given for the article was Dr. Michael Greger’s old website, although the link is dead.

    The original sources were included in the copied/pasted article. Here they are:
    [The vegan study] Results from the German Vegan Study. European Journal of Clinical Nutrition 57(August 2003):947.

    [The omnivore study] USDA. Food and Nutrient Intakes by Individuals in the United States, by Region, 1994-96.

    I wish Dr. Greger would have posted these sources in this video, and find it strange that he wouldn’t, and hasn’t replied to any of the requests for the sources.

    If you want to find more studies on omnivore nutrient deficiencies, just Google *nutrient deficiencies population’ or ‘nutrient deficiencies americans’ or ‘nutrient deficiencies europeans’ or whatever. If you type in omnivore you’ll get mainly stuff about vegans and vegetarians.

    Two recent American nutrition studies provide some contradictory info, even though they’re both by reputable sources. One by the CDC finds that only 10% of Americans have nutrient deficiencies. The other in the Journal of Nutrition found 6 common vitamin deficiencies ranging from 25% of Americans deficient in vitamin-C to 70% deficient in vitamin-D.


  • uv

    I found on a message forum where someone reposted the original blog
    article about this by Dr. Greger, but the link was to an old and defunct
    version of his website:

    Luckily they copied/pasted the sources that Dr. Greger cited:

    [Vegan nutrition study] Results from the German Vegan Study. European Journal of Clinical Nutrition 57(August 2003):947.

    [General study of Americans] USDA. Food and Nutrient Intakes by Individuals in the United States, by Region, 1994-96.

    can find more studies on omnivore nutrient deficiencies by just doing a
    web search for nutrient deficiency in the general population. Don’t put
    the word omnivore in the search… general population studies suffice
    since most people are (at this point in history) omnivores.

  • uv

    (Why does my comment disappear?)

  • Dillon Price

    The reason this is stupid is that people often use a health conscious Vegan, then some fat sack that eats McDonalds. For 1. That meat sucks and has a bunch of fillers in it. For 2. They eat a bunch of processed garbage. for 3. they don’t do anything for their health at all. Then you have the balls to turn around and talk trash about being an omnivore, and yet, they’re deficient in areas where plant eaters are not? That doesn’t even make SENSE because if they were truly omnivores they’d be eating vegetables and fruits they’d have all the vitamins that a vegan does plus everything they need from meat. The problem isn’t “meat” the problem is you’re entire universe for this study is trash and you’re not isolating the variables. It’s a joke.

    • Thea

      Dillon: re: “… plus everything they need from meat.”

      Even the conservative ADA has acknowledged that humans do not need to get any nutrients from meat:

      “It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.”

      What this means is that we can get all of our nutrients from plant foods without all of the drawbacks of eating meat. Many of those drawbacks exist regardless of where one buys the meat, how it was cooked, or how the animal was raised. This is just one study. This site, however, highlights many, many studies in the context of the “body of scientific evidence.” And the body of evidence shows why this study, among others, are relevant and meat intake is not so good for us.

      You can I can definitely agree on your second point – that people eat too much processed food. But we have enough evidence now to show that processed food is not the only problem with the American diet.

      Good luck.

      • Dillon Price

        *First off, this is not personal, I don’t hate you or think any less of you or anything in that matter; just the facts as best as I can do.* Lets see what I can do with this. First lets get this clear. My topic:1)The study compares Vegans to People who eat any old garbage. Then Pick out meat as the issue with the “any-old-garbage” eater. The universe of the study is flawed. Then (and biggest of ALL) 2) They are obviously NOT looking at Omnivores because if they WERE the people who ALSO include meat would *NOT* be “deficient” in ANYTHING that the vegans have, because he or she is ALSO eating vegetables. ———- So, you make the claim that the ADA says human’s don’t need to get any nutrients from meat. Well, I have a quote from from the ADA that disproves this claim handily: “But you’ll have to educate yourself about how to each various combinations of plant proteins to ensure you receive the essential vitamins like meat has. “— It seems that the ADA believes meat has “essential vitamins.” Source []

        A little anecdote from me: In every 5 minute Google search I’ve ever conducted There are NUMEROUS sites and scientific journals and studies with the funding displayed as well (no claiming it’s the evil meat and dairy industry) that proves Vegan myths wrong. I’m not on my home computer, but if you’re interested I can send them to you when I get home. Meat is not bad, you can’t ever make it bad no matter how much you want it to be. Your precious ADA even claimed it contains essential nutrients, so that is basically wrapped up? I don’t see how we can continue this conversation.

        • Thea

          Dillon: The idea that plants have to be combined to make complete proteins is a long disproven myth. Here is some more information if you are interested:

          TED talks can be very interesting, but are not scientific evidence in and of themselves. (And are not vetted in a way that I would take my nutrition advice from.) And neither is a Google search. (re: ” In every 5 minute Google search I’ve ever conducted … that proves
          Vegan myths wrong.”) As I’m sure you know, anything can be repeated again and again on the internet and be completely wrong. There are plenty of examples of that. Something to think about. And as shows, with the evidence to back it up, the body of scientific evidence points to a whole plant food based diet as being the healthiest/best chance of preventing the major diseases of our time.

          I can see that you are happy with your current beliefs and did not find my post helpful. So, as you say, we will leave it at that. Good luck.

          • Dillon Price

            Stop; you have made the first dodge. “dillon: The idea that plants have to be combined to make complete proteins is a long disproven myth. ” I NEVER made this claim. This “point” is moot.

            I will only go on a point by point basis with you, since you have shown a tendency to evade and shot gun your posts with fallacies and distractions such as this “protein myth” I never mentioned.

            —- This is extremely frustrating to me. I did NOT use TED talks as scientific evidence either. This is ANOTHER distraction. We’re up to 2 now. because you do’nt want to admit to being wrong. Your ego can’t handle it. You need to buckle down and Argue this ONE SINGLE POINT.—>*****************************************************************************The ADA said that MEAT IS ESSENTIAL

            I used a quote from the ADA FROM the TED website. THE SAME COMPANY YOU USED TO JUSTIFY YOUR FALSE POINT THAT MEAT IS NOT ESSENTIAL. THE ADA SAYS THAT IT IS. Point Proven.******************************* This can not be ignored. You will answer this. Period. We will discuss NOTHING further until you answer it. Now I wait.

          • Toxins

            Dillon, there is no need to become so aggressive. Also the ADA makes no such claim,

            “It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the lifecycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes. ”

            “Appropriately planned” is a key statement here. They go on to mention possible nutrient deficiencies, but as long as one is appropriately planned, the only possible deficiency is vitamin b12, which of course is supplemented.

            To your points in the last post, the standard American diet is an omnivorous diet, but that doesnt mean the quality of their diet is equivalent, just take a look at what percent of the population is deficient in certain vegetables below.

            about 80% do not get enough fruits, 88% do not get enough vegetables, about 99% do not consume enough whole grains. And keep in mind these are in line with the bare minimum guidelines for food intakes for Americans which are far too low to begin with and do not actually prevent chronic disease. Lack of plant food consumption is a nationwide health problem.

            The guidelines do not appear to significantly prevent chronic disease risk when evaluated using the healthy eating index developed by the USDA. Women are unprotected from all forms of chronic disease while men have a 28% reduced risk of heart disease.

            Furthermore, most people consuming an omnivorous diet displace their calories to consume copious amounts of animal products and saturated fats. The healthful vegan diet and current diet consumed by most Americans today is not at all comparable, and based on the mass amount of evidence available, shows that a Vegan diet can essentially reverse chronic disease, which even the “healthiest” standard American diet cannot.

  • Eskil J.

    To be fair though; over 40% of the US population aren’t getting enough vitamin B12 as of 2000 and even conservative governments like the USDA appears to recognize this.

  • Ben

    Hi Dr Greger. It’s great to see an actual doctor setting up a site like this. With real science!
    A quick google search shows a whole stalk of broccoli will cover only 11% of my DV. Is this really viable? Or is a calcium supplement a better option?

    • Toxins

      Calcium needs for humans are not as high as the DRI may recommend, and if we consumed a low sodium diet low in animal protein, our calcium needs can be as low as 450 mg per day as discussed more extensively in this article from the Food and Agriculture Organization of the UN. As represented in the figure below, and citing from the article “In a western-style diet, absorbed calcium matches urinary and skin calcium at an intake of 840 mg as in Figure 14. Reducing animal protein intakes by 40 g reduces the intercept [calcium balance] value and requirement to 600 mg. Reducing both sodium and protein reduces the intercept value to 450 mg.”

      So with 450-600 mg of calcium as a goal, msot plant foods over the course of a day will satisfy this. Eating leafy greens and beans will provide a higher amount of calcium as well. Try it out and put your daily nutrition info into

      • Ben

        This is great news (and again, real science!)

        I don’t eat meat so that’s good news and good to know a bit more about how high sodium can affect the body. I watched another video on here about vegan buddist nuns and that was a good indicator that low(er) calcium diet does not necessarily mean calcium deficiency.

        Thanks for the app looks really cool might try it out! I’m pretty proud of my broad leafy and legume intake, it could be fun to data log it!

    • Magda

      Make sure you get 15-20 min of direct sunlight daily for vit D. Many researches showed vit supplements may harm you more than help. Your body is able to make enough nutrients it needs to function properly from plant based diet. Every person is different so for what you may need 150 mg someone else may need more. Only way to know is to run periodical blood tests on all your vitamins. They one that you may be deficient is the one you have to concentrate of finding veggies with proper vitamins. Eat tons of greens collards, swiss chard or anything else you like and you are good.

  • Vorgaloth

    Grass-fed meat and wild seafood are nutrient dense super foods that are superior to grain-fed factory farmed meat. Grains are very toxic to cattle. Grains are poorly nutritious relative to organic meat and vegetables. There’s no good reason to eat them as well as dairy and legumes. Vegetables, meat and tubers should account for most of your macros. The optimal ratio differs from person to person. Healthy fats, nuts, seeds and fruit should generally be in moderation.

    • mag

      Have you heard about recent tsunami in Japan just few years ago? Since than ALL the ocean is highly contaminated with radioactive waste. They were testing oceans all over the world and all seafood is contaminated with that crap. Also meat and fish are saturated fat which are bad for us. Also our body does not absorb nutrition from meet as well as veggies. Read anything by dr Campbell or Dr Barnard for more info

  • Derrek

    I’m vegan and got hypothyroidism I think. I think Iodine is the only micronutrient I’m deficient in. I just would prefer to not have to take supplements if I don’t have to. I’d rather get them from whole foods. Any advice?

    Is there a fitness app that tracks micronutrients and everything I need?

    • Thea

      re: “Is there a fitness app that tracks micronutrients and everything I need?”

      While I haven’t used it myself, lots of people on this site are big fans of the cronometer. You just plug in your food and it tell you about the nutrients you are getting.

  • Derrek

    What sea veggies are the best kelp, dulse and etc.? Would about nori. Is it safe? But Dr. Greger also recommends not eating kelp as it has too much iodine. Can your body only absorb so much at one time?

    • Thea

      Derrek: Re: “Can your body only absorb so much at one time?” It’s more an issue of your body absorbing too much and it causing health problems. If you are interested in learning more, check out the video in this set with the title, “Too much iodine can be as bad as too little”:

      Dr. Greger *does* recommend nori. That discussion should be in one of the videos in the pile linked to above.

    • Mag

      Regular salt has no iodine, even the seasalt is a processed product that includes anticaking agents that are not neceserly good for us. Best ones so far I found in Wholefoods that is a piece of rock and homes with grater. Otherwise stick to seaweed and keep getting retested. I know Dr Barnard had some info about thyroid issues. Check his web and see if you can find any info or contact them

  • Fortunately, the interwebz never forget. Here is the cached version of that page:

  • Hunter

    I have -3 bone density ,am 71 years old and a vegan. Doctors had me on Fosamex then Alendronate and now as I went from -2 to -3 want me off those and to just take calcium and D3 supplements. McDougall says no vitamins so I’m hesitant to do anything w/o proper advice.

  • Justin

    Do you have the study talking about the calcium absorption of Kale being twice that of milk?

  • Michael

    Dr Greger, just heard a chap talk about methionine deficiencies in vegans, & saw this research paper which suggests the same – As a vegan myself, it would be awesome to know your thoughts or those of any other scholarly commenters (hey Toxins!) on this. Cheers, Michael

    • Michael

      WHOOOPS – meant to say GLUTATHIONE not methionine! Apologies! got my ‘thiones mixed up haha

  • Kevin H

    Is there a vegan treatment for pain from a bone fracture? I hurt my shoulder and my arm and shoulder hurt.

    • Joseph Gonzales R.D.

      Not that I know of. Fractures require time to heal. I think it has less to do with a vegan diet and more about allowing time for recovery. Surely, the right protein and minerals, vitamins, and antioxidants are important fracture or not. Most studies focus on prevention. Check out these 14 in pubmed if interested. Sorry about your arm :-( no fun. Hope you get better soon.

      Best wishes,

  • Christian Bramann-Lauer

    Please compare a HEALTHY Vegan to a HEALTHY Omnivore!!! This would say much more about the Nutrient Deficiencies.

  • Nathan Wind

    What about vegans and magnesium? Dr Carolyn Dean says that non of use are getting enough magnesium because the amount in plants isn;t what is advertised… Is this true?

  • Mykel18

    Hi Dr. Greger, thank you for everything you do an amazing work. I have been wondering, my mother switched to a plant based diet after a breast cancer diagnosis. Few years ago she had her thyroid gland irradiated. She now takes syntroid. Is there an issue about taking iodine supplement with this condition? Thank you very much for you answer .
    Ps: I appreciated a lot your videos on cancer topics, thank you!

  • Carmel M

    What course of action would you recommend for a 62 year old woman with severe osteoarthritis? She prefers to be vegan but has been told to eat eggs and dairy products and to have yearly injections with very unpleasant side-effects. She also has a heart condition (Prinzmetal angina) and is worried about taking calcium supplements. The “experts” seem to disagree widely.

  • M

    Dr. Greger – what about the potential benefits of fasting? I’ve watched the video – a TEDx talk given by Mark Mattson, the current Chief of the Laboratory of Neuroscience at the National Institute on Aging . at and he talks about the benefits to the brain of intermittent fasting. Do you support this for general health?

  • Jacob Prout

    Thanks to you Dr. Greger, I’ve been a vegan for the past month. Couldn’t be happier, have never been healthier. Thank You So Much For Your Work!!!

  • JakZ23

    According to doctors kids need over 8000 calories a day, but what? If kids don’t exercise they will gain at least a pound of weight per day. The FDA doesn’t want healthier people, just want peole to die.

  • VegEater

    Dogs that love humans belong with their humans. Do you force your children and other loved ones to sleep in the back yard?

    And what’s wrong with just eating whole foods? Do the societies that live the longest on earth really juice their vegetables, or do they just eat them?

  • James Patrick

    Blending veggies for a smoothie decreases nutrient potential / absorption vs. chewing the raw product….yes or no..thanks