Vitamins B12 and D: Monitoring versus Supplementing

Vitamins B12 and D: Monitoring versus Supplementing

By |2011-09-12T10:09:28+00:00September 12th, 2011|Tags: , , |46 Comments

Good nutrition is aimed at preventing nutrient deficiencies (among other things), which means that, no matter what type of diet you eat, there are circumstances where supplements may play a role. Regular vitamin B12 supplements are absolutely essential for all vegans who don’t eat B12-fortified foods every day. Depending on sun exposure, vegans may also require vitamin D (although this isn’t a vegan issue; it’s true of most omnivores, too.) And depending on individual requirements and diet, some vegans (and again, some omnivores) might require other supplements to ensure adequate intake.

An alternative to supplementing is to monitor blood levels of particular nutrients, delaying supplements until there is medical evidence that they are needed. In an effort to portray a vegan diet as a naturally optimal way of eating, some vegans will go to great lengths to avoid supplements unless they have physical proof that their diet is falling short. But that’s a bad idea. Occasional monitoring of blood levels of certain nutrients can be helpful, but it’s not a substitute for good preventative nutrition.

For one thing, being deficient—even marginally so—is not harmless. An extended period of sub-optimal B12 status—when you may feel absolutely fine because you have no acute B12 deficiency symptoms—can raise risk for heart disease. And borderline inadequacies in vitamin D status might be associated with a whole host of chronic illnesses. For some nutrients like calcium, you can go for years without feeling any physical symptoms of inadequate intake. (And you can’t assess calcium status by monitoring blood levels.)

Also, nutrient deficiencies aren’t immediately reversible. It takes time to bring blood levels back up to normal—sometimes many weeks or even months—and during that time you could be damaging your health.

Nutrient deficiencies are not really something you want to take a chance on. It’s a whole lot better to eat—and supplement—appropriately to prevent them than it is to allow a marginal intake to catch up with you. In most cases, you can prevent deficiencies with a good balanced diet based on whole plant foods. But that just isn’t true for all nutrients. If you don’t get reliable sun exposure, take a regular vitamin D supplement. If you don’t eat any animal products, make sure your diet provides adequate vitamin B12 from fortified foods or supplements. If you have reason to believe that your diet falls short on other nutrients, modify your eating habits accordingly, or—if you just can’t seem to get enough from food intake—use supplements to take up the slack.

None of this should blemish the image of veganism. A vegan diet is indeed our optimal way of eating since it represents a choice that can easily be planned to meet nutrient needs while respecting the lives of animals. Taking appropriate supplements to ensure that your vegan diet meets all nutrient needs doesn’t change that.


  1. Rosemary September 12, 2011 at 12:57 pm - Reply

    Thanks for posting this important reminder. Several of my vegan friends became B12 deficient (one seriously so), and it is all so easily prevented. I take a multivitamin and use fortified foods, and my B12 status has remained consistently healthy.

  2. beforewisdom September 12, 2011 at 2:26 pm - Reply

    In an effort to portray a vegan diet as a naturally optimal way of eating, some vegans will go to great lengths to avoid supplements

    No disrespect to anyone. In my experience this tends to happen more with health nuts than people motivated primarily by ethical eating and it is about their ego being invested in their diet.

  3. CM September 12, 2011 at 6:46 pm - Reply

    Hi I had a quick question for you. Do you ever run across people supplementing too much? I am curious about vitamin toxicity and how often to supplement if you eat a super-healthy vegetable rich vegan diet. I don’t want to feel sick from the very thing that is supposed to make me healthier, and I have run into issues in the past with a multi-vitamin, and even too much B before. Do you have suggestions for knowing how much to take when? Thanks! And thanks also for your awesome blog! 🙂

    • Ginny Messina September 15, 2011 at 11:05 am - Reply

      Vitamins, especially the fat-soluble ones, can definitely be toxic at high levels. But, unless someone is being treated for a deficiency, there is no reason to take mega-doses of nutrients. As long as you’re taking just the amounts that are needed to maintain normal blood levels, you don’t need to worry.

      Here are the amounts I recommend:

      • CM September 18, 2011 at 3:38 pm - Reply

        Thanks! This helps.

  4. Michael September 13, 2011 at 4:36 am - Reply

    Your article sounds absolutely right and sensible to me. It’s so simple and cheap to take a B12 supplement and a daily multivitamin. Every vegan should do this.

    It’s silly to pretend that a vegan diet is perfectly optimal without these supplements, or that it’s the healthiest possible diet for everybody. Or, even, in fact, that it’s a ‘diet’ as such. It’s not like just eating steak and grapefruit or whatever. I am a vegan. But what I eat probably has much more overlap with some omnivores and vegetarians than with some vegans. What I am more likely to share with other vegans, however, is an ethical commitment not to cause unnecessary harm and suffering to our fellow animals.

  5. K Scott September 13, 2011 at 6:52 am - Reply

    Thank you for posting this. I frequently send links to your blog posts because you talk so much sense! 🙂

  6. THINK ABOUT IT September 15, 2011 at 10:58 am - Reply

    ScienceDaily (Apr. 17, 2009) — A study comparing the bone health of 105 post-menopausal vegan Buddhist nuns and 105 non-vegetarian women, matched in every other physical respect, has produced a surprising result. Their bone density was identical.

    “And you can’t assess calcium status by monitoring blood levels.”

    Please provide more information on what you mean by this. Blood tests typically include a complete metabolic panel, which includes a test for calcium — in my case with a reference range of 8.6-10.2 mg/dL. I’m pretty sure i don’t meet the RDA of 1G every single day but every blood test i’ve done was within the normal range.

    Also saw this on wikipedia: In Japan, the lowest acceptable level for vitamin B12 in blood has been raised from about 200 pg/ml (145 pM) to 550 pg/ml (400 pM).

    That would mean that even people that are not vegan might just have to supplement to get an optimal amount of b12. So people, please ask yourselves, what’s worse — to take a few supplements here and there (and in the case for vitamin d, something that almost everybody should be doing anyway according to the vitamin d council) or end up like one of those people who couldn’t get things right either with the RDA’s or going crazy with the gluten and went back to eating animals?

  7. Ginny Messina September 15, 2011 at 11:10 am - Reply

    Yes, you can test your blood levels of calcium, but it won’t tell you anything about calcium status–that is, whether you’re getting enough for optimal bone health. That’s because blood calcium levels are very tightly regulated, since we need a specific level of calcium in the blood for nerve and muscle function among other things. The body maintains this narrow blood calcium range by leaching calcium from the bones or excreting it in the urine.

  8. Erin September 16, 2011 at 11:09 am - Reply

    Agreed! I take a multivitamin almost every day and try to eat fortified foods (as well as plenty of whole foods, of course). I really enjoyed the nutrition panel at Vida Vegan Con, by the way, you came across as an extremely knowledgeable presenter.

    • Ginny Messina September 17, 2011 at 8:41 am - Reply

      Thanks so much, Erin. The nutrition panel was really fun!

  9. Daisy September 17, 2011 at 8:33 am - Reply

    I’m curious as to whether you feel any responsibility for promoting this potentially dangerous diet. Virtually every day I see vegans telling each other (mostly children) that they don’t have to worry about B12: they can get it from seaweed, eat dirty veggies, they have 10 years of it stored in their liver, their body recycles it forever, or some other foolishness.

    Yes, you’re putting out good info and assuring people that taking supplements is ok. But then you vilify Tasha (the voracious vegan) when she publicly admits that the vegan diet made her sick. What signal does that send to people that might have problems with supplements? And you know that some of them do.

    • myvegancookbook September 17, 2011 at 9:34 am - Reply

      Daisy, Do your research before you go spouting off like that. The fact is that the majority that suffer from B12 deficiencies are not vegan. They are those on the Paleo diet. The meat clogs their intestines and is left undigested, which makes it hard to absorb the B12. There are also those who have a problem absorbing B12, no matter what diet they are on. B12 is everyone’s issue, not just vegans.

  10. Ginny Messina September 17, 2011 at 8:51 am - Reply

    Daisy, many people who eat meat and dairy suffer from health problems associated with food choices, so shouldn’t those who promote omnivore diets feel some responsibility for promoting this “potentially dangerous” way of eating?

    I promote ethical food choices and work to give people the tools that they need in order to eat compassionately in a way that is healthful and safe, and work to correct misconceptions about veganism that I think could be potentially harmful. I have no problem with exposing some of the “pro-vegan” myths if I think they might cause people to make poor food choices. Likewise, when people fail on vegan diets and give all kinds of pseudo-scientific reasons about why a vegan diet couldn’t work for them, I have no problem with exposing that misinformation as well.

    • Daisy September 17, 2011 at 9:03 am - Reply

      I guess I missed the “pseudo-scientific” reason you dismissed Tasha’s change of diet? She went to doctors for months. She tried supplement after supplement, yet she was still sick and you raked her over the coals for it. Exactly where was the “pseudo-science”? Or was the problem that she went public with her health issues?

      Today she eats animal foods, her health is good and she’s well enough to go back to grad school! I’d think a medical professional (like you) would consider that a good thing.

      • Ginny Messina September 19, 2011 at 3:23 pm - Reply

        Daisy, if you go back and read that post again, you’ll see that I never questioned the fact that Tasha was ill. I focused on the fact that the information she got from her doctors indicated that they didn’t understand about how to prevent deficiencies on a vegan diet and they gave her advice–according to what she said–that didn’t reflect current understanding of diet and nutrition.

      • Jaon September 19, 2011 at 11:43 pm - Reply

        Daisy: “villified”, “raked her over the coals” …

        That is slander, plain and simple. Please stop spreading such distortions Daisy. I think Ginny’s reply is spot on. Pointing out that someone has received medical advice that is confused isn’t to “villify” the person.

    • Lizzie September 18, 2011 at 9:10 am - Reply

      “..many people who eat meat and dairy suffer from health problems associated with food choices, so shouldn’t those who promote omnivore diets feel some responsibility for promoting this “potentially dangerous” way of eating?”

      Thank you for this comment – I was going to say that truly all diets need scrutiny and attention because those eating a variety of whole, nourishing foods seem to be the minority these days. And even then it’s not always enough. It may be easy to single out a vegan diet because it’s not “mainstream” but many of those pointing the finger at vegan diets are in dire need of supplementation themselves. Vegans and omnis alike can easily fall in the habit of eating “foods” that aren’t the best to build and nourish the body!

      I’ve been vegan almost 20 years (ovo-lacto for years before that) and never had a problem with B12, iron, calcium, etc. My husband, a former omnivore, has suffered with B12 and folate deficiencies, iron deficiency and low D most of his life because his digestive system is not working optimally. As a vegan, I wish we could all get past looking at specifics of “diet” and just focus on what we as individuals are eating, our specific body failings and needs and take care of ourselves. Rather than ridiculing a person for choosing to abstain from animal products, it would be wonderful to see everyone examine dietary choices and make positive changes in their own lives.

      In the meantime, I really appreciate your articles, Ginny, they give me incentive to learn more and to positively tweak my vegan diet. I also find the more I learn, the more articulate my responses to skeptics become. I’m currently living in Oklahoma where the obesity level is high and consumption of fruits, vegetables and whole grains is low. Despite the rise of their diet-related illnesses, most are still more comfortable criticising “The Vegan Freak” rather than making a few better choices themselves. Seeing veganism through an RD’s eyes is very helpful in giving educated responses.

      • Robert September 18, 2011 at 1:51 pm - Reply

        To be fair, an omnivorous diet does not necessarily equate with poor health. There are healthy omnivorous diets and there are unhealthy omnivorous diets. In fact the healthiest, longest-lived people on the planet follow healthy omnivorous diets. Sardinians and Okinawans come immediately to mind. Let us also remember that not everyone thrives on a 100% plant-based diet, which likely accounts for the fact that there are no vegan populations. The number one reason for following a vegan diet should be one of ethics since adherence to 100% plant-based diets are not required for optimal health.

        • Ginny Messina September 19, 2011 at 3:25 pm - Reply

          No, I don’t think that Lizzie was saying that omnivore diets necessarily equate with poor health, and I didn’t mean to say that either. Just that people can get sick on *any* kind of diet. It’s not the general diet, but what you do with it. Which is, I think what you’re saying, too.

  11. Matt September 17, 2011 at 12:08 pm - Reply

    Thanks for this, Ginny. Given that most people in the US will die of something related to their diet, it is always … interesting, to say the least, when people attack veganism!

    And always a good time to plug this page:

    • Ginny Messina September 19, 2011 at 3:26 pm - Reply

      Always happy to plug that page! It’s very reassuring, I think, for people who have any question about whether kids can thrive on vegan diets.

  12. Elaine Vigneault September 19, 2011 at 9:09 am - Reply

    Ginny, you wrote, “In an effort to portray a vegan diet as a naturally optimal way of eating, some vegans will go to great lengths to avoid supplements unless they have physical proof that their diet is falling short.”

    I’m not disagreeing that there are some vegans who do this. But I think they are in the extreme minority. Really, the extreme minority. I rarely meet people like this in real life. And as such an extreme minority, I don’t think their way of thinking is worthy of public criticism unless you mean to highlight their ideas because you truly think they may have some merit and ought to be investigated further.

    I think that most people who don’t supplement are either lazy, ignorant, or simply consume plenty of fortified foods so they don’t need to worry about it. If you linked to the specific vegans you’re referring to, it would make your criticism more valid and specific and thus less likely to be misunderstood or misconstrued.

    • Jaon September 19, 2011 at 11:48 pm - Reply

      If you’ve been vegan for some years you are bound to have encountered leaflets, organizations and cookbooks that spread such misinformation. I see it every month. Even if those actively pushing the anti-supplement idea are a minority they have traction with vegans that emphasize some vague idea of living “natural”. Remember also that how the veganism is portrayed in mainstream media can be significantly shaped by such minority positions. If a couple ignores nutritional advice and skips supplements while pregnant and that results in harm to the child then the media will certainly not make finer distinctions – they will declare “veganism harmful” day and night. I’m glad that the B12 supplement message is repeated time and again. It needs to be really rubbed in.

  13. Ginny Messina September 19, 2011 at 4:10 pm - Reply

    Elaine, I can’t say with any certainty what percentage of vegans actually believe or practice these things. I know only that I do run into them, and also come across these beliefs often enough on the internet and elsewhere (including questions sent to me via this blog) to make me want to share some perspective on it. Linking to one example wouldn’t do much, since as you note, it could still be an isolated incident. Instead, I write about things that pop up on my radar often enough to get my attention, or that are being promoted by someone/some resource with considerable reach.

  14. Miranda September 19, 2011 at 7:58 pm - Reply

    Ginny, do you have any opinion on Dr. Fuhrman’s supplements? I’ve been taking his vegan daily multi along with Deva’s sublingual b-12 after my doc found my levels of b-12 and vit d to be slightly low. Haven’t been re-tested yet.

  15. Paul B September 20, 2011 at 2:30 am - Reply


    Do you agree that supplements containing folic acid as opposed to getting “folate” from whole foods pose a cancer risk? It just seems really hard getting multivitamins that don’t have folic acid (Dr. Fuhrman has one but it is expensive).


    • Ginny Messina September 20, 2011 at 3:56 pm - Reply

      The research on effects of folic acid on cancer is pretty conflicting.For pregnant women, the benefits most likely outweigh the alleged risks. But most vegans get enough folate and don’t need supplements. So this is where I think taking individual supplements is best; it allows you to get what you need without getting what you don’t.

  16. Daniel September 20, 2011 at 1:32 pm - Reply

    I’m sorry to try to be the voice of reasoning here but if even before getting into a diet you foresee the possible failure of that diet (B12), shouldn’t we go back to the drawing board? I, for one, believe in nature and I know that the range where non-human primate live is tropical (google that if you must) which clearly indicate where we should live, but at the very least, where our food should come from. For me, you cannot claim a healthy diet if supplement is needed even as a prevention method. I do understand the ethical motivation but I think that sometimes it is pushed too far. An egg for example could answer, in part, the B12 dilemma without covering your hands of blood as you could easily see it as “birth control”, I would definitely be happy to see less pigeon around!

    • Ginny Messina September 20, 2011 at 4:01 pm - Reply

      If you believe in nature, then it suggests that we aren’t “meant” to live much past the age of 50–since at that point, many people require B12 supplements.

      The world has changed in such a way that a vegan diet is a good idea for us now. If we have to supplement with B12 to make it work, I don’t see why that’s a problem.

      • Robert September 21, 2011 at 9:25 am - Reply

        True. As with any other species we only need to live as long as it takes to bear and raise our young. Living beyond the child rearing years is of little benefit in nature, apart from providing easy prey for predators. Due to medical science we are living unnaturally long lives. More important than longevity is quality of life but I want it all!!! ;o)


        We are definitely better suited to the tropics and as our (my) short Canadian summer is coming to an abrupt end this week I’m liking the sound of a tropical vacay right about now!

    • Gary October 4, 2011 at 5:19 pm - Reply

      It’s natural – at least, it’s part of our better natures – to want to be kind and considerate to fellow creatures, and if we can do that as much as practical through a vegan diet and a few supplements (a product of natural inventiveness), that’s great.

    • M C November 23, 2011 at 2:00 am - Reply

      While it may be true that eating free-range eggs can be more humane than eating meat, there are no store-bought eggs that I know of that are ethically produced (even the “cage-free” ones). And you’d still be exploiting the chickens (or pigeons) by keeping them enslaved, not to mention the problem of what to do with the brothers of the hens. Unless you want to follow pigeons around and steal their eggs, of course.

      As for the nature argument, a large chicken egg contains .6 mcg. of B12. To get 2.4 mcg., which is the DRI for most adults, you would have to eat 4 eggs a day, which would also provide 844 mg. of cholesterol and 284 calories, which is about 14% of a 2000 calorie diet. From what I’ve read, other primates don’t get nearly that much of their calories from animal products.

      I guess you’ll have to decide how natural you want to be, because to emulate the non-human primates, you’ll have to start eating termites and feces. Bon apetit!

  17. […] long-time vegans, helped me to better understand the importance and need for vital nutrients like Vitamin D and Vitamin B12.  Since reading Vegan for Life, I now know how important it is for me to take a sublingual […]

  18. Daisy October 3, 2011 at 12:04 pm - Reply

    I’m a little late getting back to this discussion, but I do wonder how you deal with reputable people who claim that you don’t need to supplement for B12. T. Colin Campbell in this article, for example, seems to be telling vegans they can get B12 from their plant-only diet.

    Would you consider him somone who can be turned to as a reliable source of information? Or are you willing to change your position that to stay healthy vegans should supplement for B12?

    • Rhys October 6, 2011 at 2:48 am - Reply

      Did you read to the end of that article?

    • myvegancookbook October 7, 2011 at 8:59 am - Reply

      mmm, if you read all of that article he says at the end…

      “This was written in 1996. Now, 12 years later, I still don’t know that this view whether this view is right. However, in the meanwhile, I have been influenced by two of my clinician colleagues, Dr. Michael Greger and Dr. Alan Goldhamer, that their understanding of the literature and their experience in the clinic suggest that B12 deficiency may be seen in vegans, thus advocate B12 supplementation. I defer to their view.”

      What he is saying now is you need to supplement your B12.

    • Ginny Messina October 7, 2011 at 9:15 am - Reply

      I agree that this article is unfortunate, especially since the “update” comes after the references where many people won’t see it. This research has been used by many to justify a refusal to supplement with B12 and I wish articles like these–when shown to be incorrect–would be deleted.

      Here is Jack Norris’ perspective on the research regarding B12 uptake by plants:

  19. […] month Ginny Messina posted Vitamins B12 and D: Monitoring versus Supplementing.  Great timing! Last week I had to go back in for blood work because my B12 levels have slowly […]

  20. […] my diet. There is nothing wrong with this.  I urge you to read Ginny Messina’s post:  Vitamins B12 and D: Monitoring versus Supplementing.  I always trust her honest approach to nutrition, and veganism, and her uncompromising compassion […]

  21. Beth December 6, 2012 at 3:50 am - Reply

    Could you please comment on these articles that, as best as I can tell, say that taking Vitamin D supplements is not necessary and may be harmful and that the best solution is to get more sun – even go to a tanning salon if necessary.

    I recently found out I am deficient in Vitamin D (eating vegan diet for about a year) and trying to figure out what to do.

    My doctor says take 2000 IU for 3 months and then 1000 IU thereafter. That I’ll always have to be on Vitamin D and that my body has stopped absorbing Vitamin D.

    I would love to hear your thoughts.

    Thank you.

    • Ginny Messina December 6, 2012 at 9:47 am - Reply

      Beth, if you are deficient, I would follow your doctor’s advice. The ability to make enough vitamin D depends on many factors–your skin tone, age, where you live, for example–and even in very sunny parts of the world, some people fail to make enough. Some people just need more sun exposure than others and then you need to balance that exposure against risk for skin cancer.

      Tanning beds emit primarily UVA rays which are not the type that make vitamin D. (Vitamin D is synthesized by exposure to UVB rays.) UVA rays do contribute to skin aging and cancer, however.

      The ideal blood levels of vitamin D are definitely a controversial area, but I think that the articles you refer to may oversimplify the research on vitamin D and deficiency. There is certainly good evidence that vitamin D protects bone health as women age.

  22. […] Messina, nutritionist and registered dietician: Vitamins B12 and D: Monitoring versus Supplementing and Vitamin D Supplements Are Still Important for Some […]

  23. Cara March 5, 2013 at 9:52 am - Reply

    Hi! I realize it’s 2 years after this article was written but if anyone is still reading the comments and can help me I’d appreciate it! About 3 weeks ago I became a vegan and am really excited, but can anyone tell me if there are any brands of B12 sublingual vitamins that don’t have sugar, artificial sweeteners, fructose, citric acid, and all of the crap that I cut out of diet? For years I was really sick with horrible migraines, vomiting, muscle pain, and exhaustion and 2 days of veganism fixed what the doctors and medication couldn’t for years! 🙂 There is B12 in my multivitamin but all of the others seem to contain gross fillers (Trader Joe’s even puts lactose from milk in theirs…).

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