Vitamin B12 analogues and deficiency

Carla asks a very important and interesting question…

“Thanks for the updates… I love the reminder to check in! And you always have something interesting goin’ on… I’ve been meaning to enquire about an issue and wondered if you’d do a write up about it as I’ve not found anything definitive yet.

OK, it’s the B12 issue… we all know that spirulina and other green algae have B12 analogues in them that are NOT readily absorbed. My question is, do they interfere with the absorption of regular ol’ B12?! Some say yes, do not ingest them… others are naysayers and say they have synergistic benefits. It’s really confusing and I would like to know your take on this! Thanks… hope that makes sense :-) Have a great weekend!”

© Sifu Renka

OK, in case you think that second paragraph is written in a foreign language… it’s not :-)

Non-vegans are probably not going to have a clue what this question actually means. So a bit of background information to start…

Those making an ethical choice — vegans and vegetarians naturally want to get all their nutrition needs from food, without needing to take supplements. In part, this is because they want to justify their choices.

If they have to resort to supplements then it suggests something is wrong with the diet. They want their choices to have a sound rational basis, and who can blame them?

The problem is that animal foods are generally thought to be the only reliable source of vitamin B12. This is one of the reasons why algae has been very popular, with astonishing claims made by promoters, including the idea that algae contains lots of B12. But does it?

B12 analogues (or analogs)

B12 comes in various forms. Some of it can be used by the body directly, some can be converted by the body into a useful form and some is called inactive B12, or pseudo B12 because the body can’t use it or convert it. The useful B12 is called “true,”, “active” or “real” B12.

Often you’ll see inactive B12 called “B12 analogues”, even in scientific papers but in fact, all B12, active and inactive are analogues. Analogue just means “similar”… for our purposes anyway.

The algae Carla is asking about has generally been found to contain only inactive analogues of vitamin B12… But it gets worse… some folks are saying that inactive B12 analogues may prevent the active B12 analogues from working properly… hence Carla’s question.

If you’re planning to do some research on B12, it can be a little confusing as to which are the active B12 analogues and which are the inactive B12 analogues. The types of B12 that are “true,” “active,” “real” and useful are:

  • Cyanocobalamin
  • Methylcobalamin
  • Adenosylcobalamin
  • Hydroxocobalamin

Cyanocobalamin is the one you normally see in supplements. The B12 ends up in this form because of the process of making it with charcoal. It’s also the most stable form. Your body has to convert it to the methyl form though before it can be used, and that’s why some people think that the methyl form is better.

Why eat pond scum?

In raw vegan circles, there always seemed to be a lot of talk about the benefits of algae. But when I ventured into the raw vegan world for six months, I didn’t see the need to eat algae. There are 3 main reasons for this:

  1. I believe in eating naturally and eating algae didn’t seem so natural. Quite often I come across the “instinct” argument about meat — that we have no instinct for it. Yet many of the same folks are happy to eat algae. Well whenever I see a pond or lake with a covering of green goo, I can tell you my mouth isn’t watering.
  2. It’s expensive, and having previously spent about sixty pounds a month ($120) on top quality supplements to try and get better from ME (CFS, CFIDS), that did absolutely nothing to improve my health, I was turned off supplements as being that useful.
  3. The confusion over B12 analogues, like a lot of nutritional hot topics, can leave you banging your head against the wall, sighing a lot and making a lot of noises such as… pwwwwhhhhffff.

So, if algae only contains inactive analogues what’s all the fuss about? Why bother eating it? If we don’t eat it then we won’t have the B12 problem!

Well, that would be all fine and dandy if B12 were the only ingredient heavily promoted for algae (chlorella, spirulina, lake kalmath blue-green algae and so on…) but not so…

There are many other claims by those in favour of algae as a supplement… call me a cynic but why are most of these people selling the stuff… hmmm.

  • Complete protein — contains all the essential amino acids
  • Plant-based omega-3
  • High concentrations of vitamins and minerals

If you are relying on algae for any of these things, I think you need to seriously rethink your diet. To me, making a claim for any food that is normally outside a natural human diet based on ANY nutrient it contains is… well, logically flawed :-) Why not eat bark for fibre, or sand for minerals or your own poo for B12? The last one at least would have some logic — apes have been known to do this :-)

  • Cancer tumor inhibition and even reversal of cancer

This last one is definitely for another article, except to say that you have to wonder why we haven’t seen the headlines “Algae Triumphs Over Cancer” or even recommendations from the cancer charities to use it?


I find myself getting very irritated when I read about the benefits of CGF (chlorella growth factor — claimed to be help repair tissue and slow ageing) or any other algae containing compound or chemical with reported health benefits.

If you want benefits, then read up about the massive health benefits of fruits and vegetables which ARE a big part of the human diet and contain myriads of health-promoting stuff. You can’t blame the sellers for trying to leverage everything they can, but a lot of the claims I’ve read smack of exploitation and downright manipulation.

Irritated again to read that some algae is sold as “contains 50-75% protein”. Woweeeee you might think… but 75% of what? How many calories do you think are in that tablet or powder? How many ACTUAL GRAMS of protein? Again, half-truths abound. Grrr.

I checked out some of the suppliers of algae, here’s what I found on one sales page; (the bold is their highlighting, not mine)…

“… Approximately 65% protein by weight makes Spirulina one of the plant world’s most potent sources of protein (raw meat has 27%, and soybeans have 34%). It contains all eight essential amino acids making it a complete protein source.”

Then I checked the protein content: ***0.44g***… I’ll be generous and call it half a gram!! This is an outrageous misrepresentation.

The same sales page claims that spirulina, discovered by the Aztecs, is the PERFECT food and goes on to say;

“Spirulina is also the plant world’s most highly concentrated source of vitamin B-12. It contains an amazing array of minerals, trace elements, carotenes, essential fatty acids, enzymes, chlorophyll and other vitamins.”

But the B12 in spirulina is useless and probably even harmful. To say these claims are misleading is being kind to them. This is irresponsible.

Please! Don’t look at product sales pages for reliable information on ANYTHING.

The “acid” test

The issue of B12 analogues and food sources of B12 can be very confusing. This is because science is still learning about B12 and still developing accurate tests. It may turn out that some plant sources are a reliable source of B12. Further research needs to be done. The important word here is reliable. At the moment, all the major vegan and vegetarian organisations say there is no reliable plant source.

How can we know for sure how much active B12 is in a food and how much inactive B12? And how can we know whether the inactive analogues are preventing the active analogues from working? The answer to both these questions is MMA — Methylmalonic Acid.

The definitive test for any food is “does it prevent and correct B12 deficiency” and that’s where the MMA test comes in. This is the “gold standard” in deciding the efficacy of any food.

A thorough review of B12 states…

“The only plant foods which have been tested for B12 activity using the gold standard of lowering MMA levels in humans are dried and raw nori from Japan. Dried nori made MMA status worse, indicating that it can reduce B12 status and can possibly harm people who are B12-deficient. Raw nori kept MMA levels about the same, indicating that it didn’t harm B12 status, but it did not help either.”

So, finally the answer to: “Do inactive analogues prevent active analogues from working?”

And the answer is “pwwwwhhhhf”.

But seriously… the answer to this is “yes.” The vegetarian society are clear on the matter…

“Researchers have suggested that supposed B12 supplements such as spirulina may in fact increase the risk of B12 deficiency disease, as the B12 analogues can compete with B12 and inhibit metabolism. The current nutritional consensus is that no plant foods can be relied on as a safe source of vitamin B12.”

And so is Reed Mangals Ph.D., R.D (via the Vegan Resource Group)…

“The inactive form (also called analogues) actually interferes with normal vitamin B12 absorption and metabolism”

In the VeganHealth B12 review, a look at one scientific study states that one of the following is probably true;

1. Some B12 analogue may be harmful to the nervous system.
2. Some B12 analogue may have B12 activity in bone marrow (which produces blood cells) but not in the nervous tissue.

I think there’s been a lot of confusion in the past about this question but these days tests are more sophisticated and scientific knowledge of B12 analogues is greater. There are many reliable sources stating that yes, the inactive analogues do prevent the active B12 analogues from working and are therefore harmful.

The homocysteine link

What is very clear from my research is that B12 is a very important issue for health and disease prevention. A lot of study is being done into the link between B12, homocysteine and folate which are interrelated nutrients.

High levels of homocysteine are linked to heart disease and mental illnesses. High levels of homocysteine have been found where there’s low B12 in the diet. Vegetarians, vegans and raw vegans have been found to have high levels of homocysteine due to low dietary active B12.

The bottom line

This is serious stuff and if vegans and vegetarians wish to remain healthy it’s absolutely imperative that there is enough active B12 in the diet. That means taking a good quality supplement.

If you want to dabble with plant sources of B12 then be aware that you’re playing a very dangerous game with your health. Is it really worth it for the sake of taking a regular B12 supplement? Life is too short to spend too long on this issue or worry about it. There are much bigger fish to fry.

If you do choose the plant source option then at least have your B12 measured regularly. But you should check what type of test is offered. The serum B12 test is likely to include inactive analogues and is therefore useless for our purposes. The MMA test is the only totally reliable one that I know of.

Overall, I feel it’s safest and simplest to include some animal-source foods in your diet. It will solve the B12 issue, and although going completely raw for a while can have great healing benefits, there are still question marks over the long-term effects of a raw vegan diet.

Good health and nutrition is about getting the “big stuff” right. Eat a natural, human diet in a way that’s simple and fits in with your real life. Do that and all the details take care of themselves.

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Michael Kinnaird is the author of Happy Guide, the result of a 20 year exploration into what works for health and happiness.

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8 thoughts on “Vitamin B12 analogues and deficiency

  1. Dear Mike, I am Anjalee writing you from France, my english is not very good but i spen time and read your artical word by word about vitamin B-12, and it force me to write you back to say it is one of the best artical i have read about B-12.

    I 36yrs old woman suffring from vitiligo for last 7 yrs, spent lots of money on doctors and medicin but nothing is really working on me.

    can you please help me? please tell me what should i eat or do to get rid or looking spoted? Thank you sooooo much


    1. Hi Niki,

      I’ve been looking into vitiligo for you for the last hour or so and I am again shocked and disheartened by the short-sightedness of medicine. While there have been studies confirming the effectiveness of B-12 with folic acid with sun exposure/UVB treatment, NO-ONE is talking about the big picture.

      That is, that chronic illnesses always need a multi-pronged strategy because thousands of factors affect health outcomes… B-12 and folic acid are only a small part of the big picture. B-12 and folic acid have been spot-lighted because they were low in vitiligo sufferers as you probably know (although so was vitamin C but that is rarely mentioned).

      So… instead of looking at correcting only 3 of the thousands of factors that affect health, why not correct the WHOLE LOT?

      For example, we know that in susceptible people, gluten can damage villi — absorption sites for nutrients. So, say you were gluten intolerant which is VERY common, supplementation with B-12 and folic acid will not get to the ROOT cause of the problem. And this is one of the many flaws of the medical approach in general. For the BEST CHANCE of health, CORRECT all possible ROOT CAUSES.

      What this means in practice, is living a life that your genes expect… i.e. not much like the life the most people live.

      Also, what speaks to me as I read about vitiligo, is rather than being innocuous and purely cosmetic as is often stated, vitiligo could well be a symptom of a larger problem… autoimmune problems can lead to related problems so vitiligo sufferers are more at risk from other autoimmune problems. And B-12 deficiency is not only implicated in vitiligo but in irreversible nerve damage, and along with folic acid and homocysteine… heart disease.

      It is also very interesting that anti-inflammatory steroids are being used topically, because chronic inflammation is at the root of so many chronic illnesses.

      The truth is that everything affects everything else, not only B-12 and folic, but EVERY nutrient interacts directly or indirectly with every other in immensely complex biochemical pathways that in turn are acted upon by the body which in turn is responding to and being acted upon by the environment.

      So… in the first instance, look to your whole lifestyle to make sure you’re living the life your genes expect… human food only, sunlight, exercise, sleep, LOW STRESS, etc. And then perhaps you can look to where you need to go the extra mile to reverse deficiencies etc. You can get your doctor to check for nutrient deficiencies and then look at controlled sun exposure to help re-pigmentation — you can research this to find out the optimum program… re-pigmentation seems to happen anyway for many during summer… so call me crazy, but isn’t that a big clue? :-) In the winter, UVB lamps maybe a good way to go… as I said I’ve not looked deeply into it so please research the best NATURAL approach. I personally would not take drugs to enhance the response to UVA for example (PUVA treatment).

      From my limited look, it seems that sunlight exposure at first causes vitiligo to look worse as the pigmented skin tans, but then re-pigmentation happens later. So, it will take perseverance.

      Happy Guide will lay out for you how to get on track with the best lifestyle, addressing all factors. Please get back to me with any questions once you’ve had a full read through of the guide.

      Very best wishes,


    2. I just read in “The Paleo Answer” by Loren Cordain about a man who had 75% of his body affected by vitiligo and 10 months later, 20%. There is no follow-up because Loren describes meeting this guy at an event, and he had his before and after photos after 10 months.


  2. I tend to agree blue green algaes especially that crap grown in filthy lake klamath shouldn’t be eaten in huge quantities, also due to excessive RNA etc. But using it occasionally for certain conditions might be appropriate. I don’t think the science is cut and dried on this and the Aztecs were able to feed themselves for months on pond scum when invaders were trying to starve them out. Aztecs farmed pond scum so historically it is a food.


    1. Hi Georje,

      I agree it’s difficult to get to the truth sometimes. A red flag goes up for me when data is presented by people selling the stuff! E.g. the link you gave. You’re only ever going to get a one-sided argument from people with a vested interest. In my experience, science can be, and is, used to make pretty much any case people want to be made. The best way to come at any health dilemma is to ask “is it natural?” That usually sheds immediate light.

      The situation we have right now is humans living unnatural lives, which in time has undesirable effects, disease. Then we have other humans selling the sick humans more unnatural stuff (pills) to solve the problem. It’s nuts :-) But it’s a big money maker. All those desperate people looking for a solution… easy to sell them a quick fix. The truth is there is no quick fix, our problems can only be solved by correcting the causes.

      We would be wiser to focus on what is natural for humans and move in that direction, than to figure out if spirulina has active b-12. Alas, there is no money in it.



  3. I completely agree with your hypothesis that Spirulina/Chlorella can play havoc with the body’s absorption of nutrients. We’ve tried all brands or these products, organic and non-organic and I can tell you that they increase Uric Acid in the body (probably from the amino acids they contain) and they reduce B12 levels as picked up by tests. Also, the more you take the more you notice you feel unwell the next day. Not just me, but others too. I personally think Spirulina.Chlorella are scams at the worst level, taking in suckers to depend on these foods derived from pond scum. When was it ever “natural” to consume algae and pond scum, I don’t remember my granny every telling me they did this?
    Anyway, many things in nature are full of nutrients, doesn;t mean they are safe for human consumption, I tend to agree with your article in this case. I take various other natural supplements and have experimented with most of them, there is something about Spirlina/Chlorella that just doesn’t gel with my body or our family.


  4. I don’t sell algae products like chlorella or spirulina but I highly recommend them for their immune boosting and cancer fighting abilities.

    The very obvious reason that we do not see headlines about the algaes is the same reason that we do not see headlines about oleander extract, the ABM mushroom, cat’s claw, mutamba, colloidal silver and on an on – the cannot be patented and controlled and sold at huge profits by the trillion dollar medical industry which spends $300 Million a year promoting their products and suppressing inexpensive natural competition.

    Natural plants, herbal medicines and supplements have been used effectively for at least 6000 year. They are provided for us just the same as the foods Mother Nature provided for mankind in the diet you correctly promote.

    The only marketplace for the Big Pharma companies is our bodies. Shrinking that market by letting natural effective competitors in is not a very good profit model, just as it is not a good profit model to actually cure anything as opposed to producing expensive treatments for symptoms which have side effects that lead to still more expensive medicines, and so basically nothing has been cured since the 60’s despite huge leaps in science and technology.

    The short answer to the question of why you don’t see such headlines: it was made by nature and it works.

    I love your diet and the work you do – keep it up please!

    Live long, live healthy, live happy!


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