Dr. Michael Klaper Reveals The Truth About Vitamin B12

To download our recorded B-12 interview with Dr. Klaper, click here.
Vitamin B12 is an essential vitamin needed in DNA synthesis. It’s critical in maturing red blood cells in your bone marrow. And it helps nerve fibers form and function in your brain, spinal cord and peripheral nerves.

With a deficiency of B-12, vital cells will not develop properly. You can become anemic and suffer from spinal cord damage.

B-12 is also required to turn the amino acid homocysteine into methionine. If you have a B-12 deficiency, homocysteine will build up to toxic levels in your bloodstream, damaging your arteries and leading to atherosclerosis.

Not to be grim, but advanced B-12 deficiency will lead to paralysis, dementia and death.

Where Does B-12 Come From?
Vitamin B-12 comes from microorganisms… mostly bacteria that live in soil, water, and the digestive tracts of animals.

In centuries past, people could get B-12 by drinking from streams. Or by working in gardens and then eating without washing their hands thoroughly. Since we no longer do these things, “natural” plant based sources of Vitamin B-12 have dropped out of modern life.

It’s true that there are bacteria in the human gut that synthesize B-12. But they live well beyond the part of the intestine where B-12 is absorbed.[1]

If you’re a vegetarian, please read Lesson 9.2: Addendum for Ovo-Lacto Vegetarians after this lesson. However, if you’re a vegan, there are only two reliable sources of B-12: fortified foods and supplements. These are covered in further details later in this lesson.

Storage In Your Body
For B-12 to be absorbed from your gut into your bloodstream, it must combine with a protein secreted by the stomach lining called intrinsic factor.

B-12 is stored in your blood, liver and muscles. 0.2% of your B-12 stores are lost each day.[2] So if you don’t consume a regular, reliable source of B-12, you’ll eventually become deficient. This could take years to manifest fully.

Unfortunately, the medical literature brims with case studies of vegans — infants, children, adults, and the elderly — who’ve incurred bodily damage from B-12 deficiency.[3]

Long-term vegans who don’t supplement may not appear to suffer in the short term. But they may actually have elevated levels of homocysteine, or subtle neurologic dysfunction.

Two subgroups of vegans are at particular risk.

  1. Vegans who avoid fortified foods like cereal, rice milk, and soy milk. These most typically include raw food vegans and macrobiotics.
  2. Infants who are breast fed, and whose vegan mothers don’t consume enough B-12.[4]

If these groups don’t supplement their diets with a reliable B-12 source, they will eventually develop deficiency.

Signs of Deficiency
In adults, typical deficiency symptoms include loss of energy, tingling, numbness, reduced sensitivity to pain or pressure, blurred vision, abnormal gait, sore tongue, poor memory, confusion, hallucinations and personality changes.

These symptoms often develop gradually over several months to a year before the B-12 deficiency is recognized.

They’re usually reversible on administration of B-12. But there’s no entirely consistent and reliable set of symptoms. And there are cases of permanent damage in adults from B-12 deficiency.

If you suspect a problem, then get a skilled diagnosis from a medical practitioner. Unfortunately, the symptoms above can be caused by other problems too, not just B-12 deficiency.

How Can You Test For B-12 Deficiency?
Measuring B-12 levels in the blood is not accurate. That’s because the B-12 analogues in sea vegetables, green powders, and other foods can give a falsely high reading of B-12 in your blood.

What’s more, even if you have “normal” B-12 levels, damage to your nerves and an elevation of homocysteine levels can still occur.

Damage to your nerves and brain can occur long before anemia manifests. So waiting to see if anemia shows up is waiting too long.

For these reasons, the best tests measure the amount of homocysteine and MMA (methylmalonic acid) in your blood. These substances increase when B-12 is deficient. If either of these levels (or both) are elevated, you have presumptive evidence of a B-12 deficiency. It should be treated immediately with oral B-12 supplementation.

If you do get your B-12 level checked, the value should be at least 350 mcg/dl.[5]

How Much B-12 Do You Need To Take Daily To Avoid Problems?
Little of the B-12 you swallow is actually absorbed. So we recommend a daily intake of…

  1. 5 mcg daily from fortified food like cereal, rice milk, and soy milk. Read the food label to determine how much B-12 is present in each serving.
  2. 100 mcg from a daily supplement, preferably chewed to increase absorption. We recommend www.veganmultivitamin.com, which contains 30 mcg of Vitamin B12… that’s 500% the US RDA.
  3. 2000 mcg from a weekly supplement to keep your B-12 level in the safe range.[6]

Vitamin B-12 can be absorbed orally, even if intrinsic factor is deficient, if enough B-12 is taken.[7]

Where B-12 is Not Found.
The soil particles on unwashed vegetables or vegetables do not supply adequate B-12 to prevent deficiency. This is true even if they’re left sitting at room temperature.[8]

Foods commonly reported as “good B-12 sources” are usually tested with methods that measure B-12 analogues. Those methods give no accurate measure of the true B-12 content, nor whether it might actually be dangerous from its analogue content.

These foods include tempeh, tofu, amesake rice, barley miso, miso, natto, rice miso, shoyu, tamari, and umeboshi prunes. These foods don’t contain B-12 on a consistent enough basis to fulfill your daily requirements. [9]

Seaweeds, especially nori, have so many B-12 analogues, that they may actually cause B-12 deficiency by blocking the action of active B-12.[10]

Only dulse may be a reliable B-12 source. But to meet your B-12 requirements from dulse alone, you’d have to eat large amounts of it daily. And the amount of iodine from that much dulse would likely become toxic to your thyroid gland.[11]

Merchandisers of blue-green algae[12] (from Klamath Lake, OR), chlorella[13] and spirulina[14] all claim B-12 is present in their products. However, the tests they use all measure analogues. So the amount of active B-12 in their products is unknown and the presence of analogues in these products might actually precipitate B-12 deficiency.

If a merchandiser states that their product is a good source of B-12, they should offer “gold standard” proof. Namely, they should show that their product lowers levels of homocysteine or MMA in the blood. All other test methods are suspect.

Where B-12 is Found in Vegan Diets.
Vitamin B-12 is commonly added to commercial rice milk, soy milk, and cereal. It is also added to many meat analogues made from wheat gluten or soybeans. However, meat analogues tend to be high in salt, fat, and artificial ingredients; so we do not recommend them.

Read the labels to see how much B-12 is in each serving.

Brewer’s and nutritional yeast do not naturally contain B-12. But one brand, Red Star Vegetarian Support Formula, also known as Red Star Yeast T6635+, fortifies their product with 5 mcg per tablespoon.

In Lesson 9.4, we provide suggestions for including nutritional yeast in your everyday meals. However, we have two cautions against relying upon Red Star nutritional yeast as your sole B-12 source:

  1. It’s often sold from bins in natural food stores, run by humans. Humans not infrequently make mistakes and the wrong yeast can be ordered from a list of many yeast products, or a non-fortified type be placed in the bin labeled as a fortified product.
  2. B-12 deteriorates in sunlight, so even the advertised amounts may not be present in the product one buys.

If you buy B-12 fortified nutritional yeast, be sure to keep it in your refrigerator or freezer, and keep it out of the sunlight.

Note: Yeast products, like nutritional yeast, will not cause the growth of candida or any other type of yeast in your body. Besides being a totally different kind of yeast from candida, nutritional yeasts are processed so that no living yeast organisms are present.

Is There A Vegan Alternative To B-12 Fortified Foods and Supplements?
The short answer is “No.”

As mentioned earlier, our ancestors could get B12 by drinking from streams. Or by working in gardens and then eating without washing their hands thoroughly. Since we no longer do these things, “natural” plant-based sources of Vitamin B-12 have dropped out of modern life.

And the modern world, with its oxidizing air pollution, chlorinated drinking water, thinning ozone layer, etc, places metabolic demands on our bodies that the ancients and their diets never faced.

If you’re vegan, eating B-12 fortified foods or supplements is not optional. It’s absolutely necessary.

If you’re a purist who doesn’t eat commercial rice milk, soy milk, or cereal — and you also shun supplements — then have your B-12, MMA, and homocysteine levels checked annually. If the values become abnormal, begin B-12 supplementation immediately.

However, don’t even consider this option if you’re pregnant, trying to become pregnant, or nursing an infant.

Recommendations: Food Sources and Supplements.
Both vegans and vegetarians should obtain sufficient B-12 from fortified food or supplements. Again, we recommend www.veganmultivitamin.com, which contains 30 mcg of Vitamin B12… that’s 500% the US RDA.

It is not wise to rely upon any sea vegetables such as algae, nori, or spirulina or upon brewer’s yeast, tempeh, or “living” vitamin supplements that use plants as a sole source of B12.

Nor is it wise to rely solely on one type of fortified food, such as Red Star Nutritional Yeast.

Recommendation for Vegan Infants.
The Institute of Medicine recommends that infants of vegan mothers be supplemented with B12 from birth. That’s because their stores at birth and their mother’s milk supply may be low.[15]
Exceptions to these Recommendations.
People with digestive or malabsorption diseases — such as pernicious anemia — B12 metabolism defects, kidney failure, or cyanide metabolism defects should consult an accredited health professional.[16]

[1] Dong A, Scott SC. Serum vitamin B12 and blood cell values in vegetarians. Ann Nutr Metab 1982;26(4):209-16. 30.
Okuda K, Yashima K, Kitazaki T, Takara I. Intestinal absorption and concurrent chemical changes of methylcobalamin. J Lab Clin Med. 1973 Apr;81(4):557-67.

[2] Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.


[3] Ashkenazi S, Weitz R, Varsano I, Mimouni M. Vitamin B12 deficiency due to a strictly vegetarian diet in adolescence. Clinical Pediatrics 1987;26(Dec):662-663.
Brants HA, Lowik MR, Westenbrink S, Hulshof KF, Kistemaker C. Adequacy of a vegetarian diet at old age (Dutch Nutrition Surveillance System). J Am Coll Nutr 1990 Aug;9(4):292-302. Dwyer JT, Dietz WH Jr, Andrews EM, Suskind RM. Nutritional status of vegetarian children. Am J Clin Nutr 1982 Feb;35(2):204-16.

[4] Gambon RC, Lentze MJ, Rossi E. Megaloblastic anaemia in one of monozygous twins breast-fed by their vegetarian mother. Eur J Pediatr 1986 Dec;145(6):570-1.
Drogari E, Liakopoulou-Tsitsipi T, Xypolyta-Zachariadi A, Papadellis F, Kattamis C. Transient methylmalonic aciduria in four breast fed neonates of strict vegetarian mothers in Greece. Journal of inherited metabolic disease. 1996 19S:A84. Abstract.

[5] Lindenbaum J, Rosenberg IH, Wilson PW, Stabler SP, Allen RH. Prevalence of cobalamin deficiency in the Framingham elderly population. Am J Clin Nutr. 1994 Jul;60(1):2-11.

[6] Tucker KL, Rich S, Rosenberg I, Jacques P, Dallal G, Wilson PW, Selhub J. Plasma vitamin B-12 concentrations relate to intake source in the Framingham Offspring study. Am J Clin Nutr 2000 Feb;71(2):514-22.

[7] Norberg B. Turn of tide for oral vitamin B12 treatment. J Intern Med 1999 Sep;246(3):237-8. Lederle FA. Oral cobalamin for pernicious anemia. Medicine’s best kept secret? JAMA 1991 Jan 2;265(1):94-5.
Kuzminski AM, Del Giacco EJ, Allen RH, Stabler SP, Lindenbaum J. Effective treatment of cobalamin deficiency with oral cobalamin. Blood 1998 Aug 15;92(4):1191-8. Delpre G, Stark P, Niv Y. Sublingual therapy for cobalamin deficiency as an alternative to oral and parenteral cobalamin supplementation. Lancet 1999 Aug 28;354(9180):740-1.

[8] Dong & Scott29 (1982, USA) examined 83 subjects from an American Natural Hygiene Society conference. They tended to follow natural hygiene diets consisting of whole raw fruits, vegetables, nuts, and seeds, with a minimal intake of grains and legumes. They considered this to be a natural primate diet and believed their bodies received B12 through small intestinal bacteria which live only in the intestines of those who follow whole raw food diets. Table 8.5.1 shows the results among subjects who did not supplement with B12. Macrocytosis among the vegetarians was minimal. One 63-year-old vegan with a sB12 of 117 (MCV = 86 fl) had a nerve related disorder. For males who did not take B12 supplements, there was a correlation between length of time as a vegetarian and lower sB12. Among subjects who had taken B12 or multivitamins, all had sB12 levels above 200 pg/ml. Dong & Scott concluded that there is no indication that natural hygiene vegetarian diets contribute to higher sB12 levels than other vegetarian diets.

[9] van den Berg H, Dagnelie PC, van Staveren WA. Vitamin B12 and Seaweed. Lancet Jan 30, 1988.
Areekul S, Churdchu K, Pungpapong V.
Serum folate, vitamin B12 and vitamin B12 binding protein in vegetarians. J Med Assoc Thai 1988 May;71(5):253-7.

[10] Specker BL, Miller D, Norman EJ, Greene H, Hayes KC. Increased urinary methylmalonic acid excretion in breast-fed infants of vegetarian mothers and identification of an acceptable dietary source of vitamin B-12. Am J Clin Nutr 1988 Jan;47(1):89-92.

[11] van den Berg H, Dagnelie PC, van Staveren WA. Vitamin B12 and Seaweed. Lancet Jan 30, 1988.

[12] Schneider Z, Stroinski A. Comprehensive B12. New York: Walter de Gruyter, 1987.

[13] Pratt R, Johnson E. Deficiency of vitamin B12 in Chlorella. J Pharm Sci. 1968 Jun;57(6):1040-1.

[14] Herbert V, Drivas G. Spirulina and Vitamin B12. JAMA 1982;248(23):3096-7.,
Watanabe F, Katsura H, Takenaka S, Fujita T, Abe K, Tamura Y, Nakatsuka T, Nakano Y. Pseudovitamin B(12) is the predominant cobamide of an algal health food, spirulina tablets. J Agric Food Chem. 1999 Nov;47(11):4736-41.

[15]  Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academy Press; 2000.

[16] What Every Vegan Should Know about Vitamin B12, http://www.veganoutreach.org/health/b12letter.html

21 Comment(s)

  1. Didn't see any mention of bee pollen…. I've read that is a very complete source of B's.

    Ali | Reply

  2. For Ali: While Bee Pollen is a great source of B-Vitamins it does not contain B-12 so should not be used for that purpose. Often when people talk about “b vitamins” as a whole they are not counting B-12.

    Tristan - Forum Moderator | Reply

  3. I take supplements to be on the safe side but I also drink kombucha, the one with ginger is my favorite, and I think that is a good source of vegan B12.

    Helene Jimenez | Reply

  4. Helene – Kombucha is not a source of B12 from my understanding. Most fermented foods generate very, very, very little B12. You’d have to consume gallons of sauerkraut just to get a day’s supply of B12 (on average, levels will vary depending on the batch and fermentation conditions).

    Part of my basis for believing that kombucha is not a source is because I do get low on B12. My mood will plummet and so will my energy levels. Then I’ll take a sublingual supplement and I’ll feel a lot better within 24 hours. I drink kombucha almost every day. It helps my digestive system. (I had severe stomach ulcers in the past, and rehabilitating my digestive system fully has been quite the trick!)

    Hope this information helps.

    Raederle Phoenix | Reply

  5. I have read that a sublingual tablet put under the tongue is the best way

    elaine goodwin | Reply

  6. It’s ineffective to consume foods that have synthetic vitamins added to them or supplements that use synthetic vitamins.

    To get sufficient Vitamin B12 you need to take a supplement that has the methylcobalamin form of Vitamin B12 and it should contain at least 1000 mcg per daily serving.

    Methylcobalamin is a metabolically active form of B12 and the only form that crosses the blood brain barrier. The common synthetic form of cyanocobalamin is not metabolically active and must be converted by the liver into its active form before the body can use it.

    It’s also important that supplements don’t contain stearic acid or other stearates like magnesium stearate or calcium stearate because they are toxic chemical additives that come from hydrogenated vegetable oils and interfere with absorption of the active ingredients in supplements.

    Ty | Reply

  7. Elaine,

    Absolutely. Just be sure that it is methylcobalamin, like Ty said.

    Raederle Phoenix | Reply

  8. What about transdermal B12 patches?

    Marie | Reply

  9. Helene: Kombucha, may have active B-12 but it will also have analogues so also shouldn’t be used as a B-12 source.

    Marie: Transdermal B-12 patches are an excellent option if you have very low levels of B-12 or if you have poor digestive and absorptive capacities. It makes sense to me to do the patch a few times a year just to be on the safe side. I saw my grandfather use these and go from a catatonic state to once again talkative and coherent.

    Tristan - Forum Moderator | Reply

  10. Hi, thank you for this great informative article! Blessings.

    Rhonda | Reply

  11. Your link to veganmultivitamin.com takes me to Dr Fuhrman’s website – is that correct?

    Diane | Reply

  12. Hi Diane — yes that’s right. We recommend his products.

    valarcher | Reply

  13. Thank you for the article. Your numbers don’t add up though. In ‘how much do we need’ you recommend a 100mcg of one type or 30mcg a day of another but then the weekly rcommendation is for 2000 mcg? Could you please clarify?

    Charmaine | Reply

  14. Hi Charmaine – the 2000 mcg/week is a top-up. It’s in addition to whatever you take daily.

    Val Archer | Reply

  15. Thank you for providing this information to everyone.

    Flora | Reply

  16. Thank s lot very extensive detailed info on B12.its great help.

    Jithendranath | Reply

  17. I have heard that bladderwack and dandilion greens both contain b12.
    Is this not what your research is finding?

    mary | Reply

  18. Hi Mary – bladderwrack and other sea vegetables have B12 analogs, not B12. Dandelion greens may well have B12 on them if picked fresh and not washed, so the bacteria are still present. B12 is not in leafy greens. It’s the bacteria on the leaf that’s producing the B12.

    Val Archer | Reply

  19. B12 is abundant in soil which can be eaten in small portions. Fermented food should have B12 since bacteria make it NOT animals.

    Natural soil | Reply

  20. When you say that “we” no longer work in gardens and eat without washing our hands, who are you implying does not do this any longer? I do. In fact I purposely eat very fertile soil specificly for the microorganisms. So who is the “we”? If the answer is you may I ask why you would recommended eating man made things instead of growing your own food and eating quality dirt?

    Atom Tedino | Reply

  21. To reiterate: We all need vitamin B12 (cobalamin). It is so valuable for many reasons, but it may be the cure for Alzheimer’s by “dissolving” the amyloid plaques in the brain. Those plaques (consisting mostly of homocysteine) build up from our day of birth, unless we maintain adequate B12 levels. B12 restores sharpness and clarity to our brains. Most supplements consist of cyano-cobalamin — which is one molecule of cyanide foe every molecule of B12. It is the cheapest form. DO NOT take this. Only take methyl-cobalamin, the active form needed by the body without requiring conversion in the liver. ONLY take it sublingually, not “orally”, since then all of it (that you don’t swallow) gets absorbed directly into your blood stream. Our guts can only absorb B12 in the terminal ileum, a tiny portion of our small intestine, so any gut problem (such as diarrhea) can result in limited absorption. Any gastric problem limiting intrinsic factor will also limit absorption. Injections are costly and unnecessary (and are usually cyano-cobalamin, and low-dose). Finally, take 1000 mcg with each daily sublingual dose for the rest of your life. There is no known toxicity for B12 (or for K2), and studies show remarkable results in improved cognition at this dose. Summary, 1000 mcg of sublingual methyl-cobalamin daily. It changes/improves your life.

    Martin, M.D. | Reply

Post a Comment

Please send me
(select one or both):

Vegan Recipes
Vegan Health Secrets
Teaching & Coaching Tips

We respect your privacy!