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What Every Vegan Should Know About Vitamin B12

Very low B12 intakes can cause anaemia and nervous system damage.

The only reliable vegan sources of B12 are foods fortified with B12

(including some plant milks, some soy products and some breakfastcereals) and B12 supplements. Vitamin B12, whether in supplements,fortified foods, or animal products, comes from micro-organisms.

Most vegans consume enough B12 to avoid anaemia and nervoussystem damage, but many do not get enough to minimise potentialrisk of heart disease or pregnancy complications.

To get the full benefit of a vegan diet, vegans should do one of thefollowing:

eat fortified foods two or three times a day to get at leastthree micrograms (g or mcg) of B12 a day or take one B12 supplement daily providing at least 10

micrograms or take a weekly B12 supplement providing at least 2000

micrograms.If relying on fortified foods check the labels carefully to make sure youare getting enough B12. For example, if a fortified plant milk contains 1microgram of B12 per serving then consuming three servings a day willprovide adequate vitamin B12. Others may find the use of B12supplements more convenient and economical.

The less frequently you obtain B12 the more B12 you need to take, asB12 is best absorbed in small amounts. The recommendations abovetake full account of this. There is no harm in exceeding therecommended amounts or combining more than one option.

Good information supports vegan health, pass it around.

If you don't read another word about B12 you already know all youneed to know. If you want to know more, read on.

This information was prepared by Stephen Walsh, a UK Vegan Societytrustee, and other members of the International Vegetarian Unionscience group (IVU-SCI), in October 2001. This information may befreely reproduced but only in its entirety.

Vitamin B12 and vegan diets - Lessons from history

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B12 is an exceptional vitamin. It is required in smaller amounts thanany other known vitamin. Ten micrograms of B12 spread over a dayappears to supply as much as the body can use. In the absence of anyapparent dietary supply, deficiency symptoms usually take five yearsor more to develop in adults, though some people experience problems

within a year. A very small number of individuals with no obviousreliable source appear to avoid clinical deficiency symptoms for twentyyears or more. B12 is the only vitamin that is not recognised as beingreliably supplied from a varied wholefood, plant-based diet with plentyof fruit and vegetables, together with exposure to sun. Manyherbivorous mammals, including cattle and sheep, absorb B12produced by bacteria in their own digestive system. B12 is found tosome extent in soil and plants. These observations have led somevegans to suggest that B12 was an issue requiring no special attention,or even an elaborate hoax. Others have proposed specific foods,

including spirulina, nori, tempeh, and barley grass, as suitable non-animal sources of B12. Such claims have not stood the test of time.

In over 60 years of vegan experimentation only B12 fortified foods andB12 supplements have proven themselves as reliable sources of B12,capable of supporting optimal health. It is very important that allvegans ensure they have an adequate intake of B12, from fortifiedfoods or supplements. This will benefit our health and help to attractothers to veganism through our example.

Getting an adequate amount of B12

National recommendations for B12 intakes vary significantly fromcountry to country. The US recommended intake is 2.4 micrograms aday for ordinary adults rising to 2.8 micrograms for nursing mothers.

The German recommendation is 3 micrograms a day. Recommendedintakes are usually based on 50% absorption, as this is typical for smallamounts from foods. To meet the US and German recommendationsyou need to obtain sufficient B12 to absorb 1.5 micrograms per day onaverage. This amount should be sufficient to avoid even the initialsigns of inadequate B12 intake, such as slightly elevated homocysteine

and MMA levels, in most people. Even slightly elevated homocysteineis associated with increased risk of many health problems includingheart disease in adults, preeclampsia during pregnancy and neuraltube defects in babies.

Achieving an adequate B12 intake is easy and there are severalmethods to suit individual preferences. Absorption of B12 varies fromabout 50%, if about 1 microgram or less is consumed, to about 0.5%

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for doses of 1000 micrograms (1 milligram) or above. So the lessfrequently you consume B12, the higher the total amount needs to beto give the desired absorbed amount.

Frequent use of foods fortified with B12 so that about one microgram

of B12 is consumed three times a day with a few hours in between willprovide an adequate amount. Availability of fortified foods varies fromcountry to country and amounts of B12 vary from brand to brand, soensuring an adequate B12 supply from fortified foods requires somelabel reading and thought to work out an adequate pattern to suitindividual tastes and local products.

Taking a B12 supplement containing ten micrograms or more dailyprovides a similar absorbed amount to consuming one microgram onthree occasions through the day. This may be the most economicalmethod as a single high potency tablet can be consumed bit by bit.

2000 micrograms of B12 consumed once a week would also provide anadequate intake. Any B12 supplement tablet should be chewed orallowed to dissolve in the mouth to enhance absorption. Tablets shouldbe kept in an opaque container. As with any supplement it is prudentnot to take more than is required for maximum benefit, so intakesabove 5000 micrograms per week should be avoided despite lack ofevidence for toxicity from higher amounts.

All three options above should meet the needs of the vast majority ofpeople with normal B12 metabolism. Individuals with impaired B12

absorption may find that the third method, 2000 micrograms once aweek, works best as it does not rely on normal intrinsic factor in thegut. There are other, very rare, metabolic defects that requirecompletely different approaches to meeting B12 requirements. If youhave any reason to suspect a serious health problem seek medicaladvice promptly.

Symptoms of B12 deficiency

Clinical deficiency can cause anaemia or nervous system damage.Most vegans consume enough B12 to avoid clinical deficiency. Two

subgroups of vegans are at particular risk of B12 deficiency: long-termvegans who avoid common fortified foods (such as raw food vegans ormacrobiotic vegans) and breastfed infants of vegan mothers whoseown intake of B12 is low.

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

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and personality changes. Often these symptoms develop graduallyover several months to a year before being recognised as being due toB12 deficiency and they are usually reversible on administration ofB12. There is however no entirely consistent and reliable set ofsymptoms and there are cases of permanent damage in adults from

B12 deficiency. If you suspect a problem then get a skilled diagnosisfrom a medical practitioner as each of these symptoms can also becaused by problems other than B12 deficiency.

Infants typically show more rapid onset of symptoms than adults. B12deficiency may lead to loss of energy and appetite and failure to thrive.If not promptly corrected this can progress to coma or death. Againthere is no entirely consistent pattern of symptoms. Infants are morevulnerable to permanent damage than adults. Some make a fullrecovery, but others show retarded development.

The risk to these groups alone is reason enough to call on all vegans togive a consistent message as to the importance of B12 and to set apositive example. Every case of B12 deficiency in a vegan infant or anill informed adult is a tragedy and brings veganism into disrepute.

The homocysteine connection

This is not however the end of the story. Most vegans show adequateB12 levels to make clinical deficiency unlikely but nonetheless showrestricted activity of B12 related enzymes, leading to elevatedhomocysteine levels. Strong evidence has been gathered over the pastdecade that even slightly elevated homocysteine levels increase risk ofheart disease and stroke and pregnancy complications. Homocysteinelevels are also affected by other nutrients, most notably folate. Generalrecommendations for increased intakes of folate are aimed at reducinglevels of homocysteine and avoiding these risks. Vegan intakes offolate are generally good, particularly if plenty of green vegetables areeaten. However, repeated observations of elevated homocysteine invegans, and to a lesser extent in other vegetarians, show conclusivelythat B12 intake needs to be adequate as well to avoid unnecessaryrisk.

Testing B12 status

A blood B12 level measurement is a very unreliable test for vegans,particularly for vegans using any form of algae. Algae and some otherplant foods contain B12-analogues (false B12) that can imitate trueB12 in blood tests while actually interfering with B12 metabolism.Blood counts are also unreliable as high folate intakes suppress the

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anaemia symptoms of B12 deficiency that can be detected by bloodcounts. Blood homocysteine testing is more reliable, with levels lessthan 10 micromol/litre being desirable. The most specific test for B12status is methylmalonic acid (MMA) testing. If this is in the normalrange in blood (

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isolation but must allow all six billion people to thrive and achieve asustainable coexistence with the many other species that form the"living earth". From this standpoint the natural adaptation for most(possibly all) humans in the modern world is a vegan diet. There isnothing natural about the abomination of modern factory farming and

its attempt to reduce living, feeling beings to machines. In choosing touse fortified foods or B12 supplements, vegans are taking their B12from the same source as every other animal on the planet - micro-organisms - without causing suffering to any sentient being or causingenvironmental damage.

Vegans using adequate amounts of fortified foods or B12 supplementsare much less likely to suffer from B12 deficiency than the typical meateater. The Institute of Medicine, in setting the US recommendedintakes for B12 makes this very clear. "Because 10 to 30 percent of

older people may be unable to absorb naturally occurring vitamin B12,it is advisable for those older than 50 years to meet their RDA mainlyby consuming foods fortified with vitamin B12 or a vitamin B12-containing supplement." Vegans should take this advice about 50 yearsyounger, to the benefit of both themselves and the animals. B12 neednever be a problem for well-informed vegans.

Good information supports vegan health, pass it around.

Further information:

Dietary Reference Intakes for Thiamin, Riboflavin, Niacin,Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin,and Choline, National Academy Press, 1998 ISBN 0-309-06554-2

Vitamin B12: Are you getting it?, by Jack Norris Homocysteine in health and disease, ed. Ralph Carmel and

Donald W. Jacobsen, Cambridge University Press, 2001,ISBN 0-521-65319-3

Endorsers include:EVA Ethisch Vegetarisch Alternatief, Belgium,www.vegetarisme.be Farm Animal Reform Movement (FARM),www.farmusa.org People for the Ethical Treatment of Animals,www.peta.com Vegan Action, US, www.vegan.org Vegan Outreach, US,www.veganoutreach.org The Vegan Society, UK,www.vegansociety.comPaul Appleby, medical statistician, UKDr LucianaBaroni, MD, Neurologist-Geriatrician, President of Societ Scientifica diNutrizione Vegetariana, Italy, www.scienzavegetariana.it AmandaBenham, Accredited Practising Dietitian, Dietitians Association of

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Australia's nominated expert on vegetarian nutritionDr Glynis Dallas-Chapman, MB, BS, UK Brenda Davis, RD, Co-author of Becoming Veganand former Chair of the Vegetarian Nutrition Dietetic Practice Group ofthe American Dietetic Association Michael Greger, MD, USA Dr WilliamHarris, MD, USA, www.vegsource.com/harrisProf. em. Dr. Marcel

Hebbelinck, Belgium Alex Hershaft, PhD, President, FARM, USA SandraHood, State Registered Dietitian and UK Vegan Society dietaryconsultant Dr Gill Langley, MA PhD MIBiol, author of Vegan Nutrition,UK Stephen R. Kaufman, MD, USA; Vesanto Melina, MS, RD, Co-authorof Becoming Vegan, www.nutrispeak.com Reed Mangels, PhD, RD,Nutrition Advisor, The Vegetarian Resource Group, USAVirginiaMessina, MPH, RD, Co-author of the Dietitians Guide to VegetarianDiets Jack Norris, RD, Vegan Outreach director and author ofwww.veganoutreach.org/health/b12.htmlDr John Wedderburn, MB, ChB,Founder of the Hong Kong Vegan Society,www.ivu.org/hkvegan

Is B12 Vegan?

The vitamin B12 component in B12 supplements andfortified foods is made by bacteria and sourced frombacteria cultures; it is not taken from animal products.However, some companies might put gelatin in their

B12 supplements, though this appears to be less andless common. It is easy to find vegan B12supplements on the Internet or in grocery stores indeveloped countries.

There are some live food supplement companies thatrely on spirulina or other algae, rather than bacteriacultures, as a source of vitamin B12. You should not

rely on such products for your vitamin B12 as testinghas indicated it is not a reliable source of activevitamin B12 (more information).

Streptomyces griseus, a bacterium once thought to bea yeast, was the commercial source of vitamin B12 for

http://veganhealth.org/b12/plant#bluegreenhttp://veganhealth.org/b12/plant#bluegreen

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many years (8, 9). The bacteria Propionibacteriumshermanii and Pseudomonas denitrificans have nowreplacedS. griseus (10). At least one company, RhonePoulenc Biochimie of France, is using a geneticallyengineered microorganism to produce B12 (11).

Fortified Foods

There are many vegan foods fortified with B12. Theyinclude non-dairy milks, meat substitutes, breakfastcereals, and one type of nutritional yeast.

The "Daily Value" for B12 found on food labels isbased on 6 g, which was the RDA in 1968. If a labelsays a food has, for example, 25% of the Daily Valueof B12, it has 1.5 g (25% of 6 g = 1.5 g).

Brewer's and Nutritional Yeasts

Brewer's and nutritional yeasts do not contain B12

unless they are fortified with it. There is at least onevegan, B12-fortified yeast currently on the market:Red Star Vegetarian Support Formula. (Twinlab'sSuperRich Yeast Plus contains whey).

Unfortunately, there are some drawbacks to relyingsolelyon B12-fortified nutritional yeast for B12:

Nutritional yeast often comes from bins in healthfood stores. If not careful, it would be easy for astore employee to order the wrong nutritionalyeast out of the distributor catalogs which oftenlist many yeasts. It would also be easy toaccidentally put the wrong yeast into the

http://www.veganhealth.org/b12/vegansources#fn8http://www.veganhealth.org/b12/vegansources#fn9http://www.veganhealth.org/b12/vegansources#fn10http://www.veganhealth.org/b12/vegansources#fn11http://lesaffre-yeast.com/red-star/http://www.vitacost.com/Twinlab-SuperRich-Yeast-Plus#IngredientFactshttp://www.veganhealth.org/b12/vegansources#fn8http://www.veganhealth.org/b12/vegansources#fn9http://www.veganhealth.org/b12/vegansources#fn10http://www.veganhealth.org/b12/vegansources#fn11http://lesaffre-yeast.com/red-star/http://www.vitacost.com/Twinlab-SuperRich-Yeast-Plus#IngredientFacts

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Vegetarian Support Formula bin.

B12 is light sensitive. Nutritional yeast is likely to beexposed to the light because it is often stored in

clear bins or plastic bags. At least one vegan who thought he was getting B12

from nutritional yeast developed B12 deficiencysymptoms that cleared up upon taking a B12supplement.

If you are trying to use Red Star Vegetarian SupportFormula for B12, make sure you are actually gettingwhat you think. It is also best to keep it in therefrigerator or freezer, out of the light.

Please note: Red Star Vegetarian Support Formulanutritional yeast has many other nutrients and I eat itmyself; but vegans shouldn't rely on it for their solesource of B12, in my opinion.

Cooking

Tucker et al. (2000, USA, 13) found that vitamin B12from fortified breakfast cereals and dairy products wasassociated with better vitamin B12 status than wasB12 intake from red meat, poultry, and fish, leadingthe researchers to suspect that the B12 from meatmight be damaged by cooking. The B12 in animalfoods tendsnotto be cyanocobalamin, the form usedin fortified foods and that is more stable duringcooking. For example, in an acid medium (pH 4-7),cyanocobalamin can withstand boiling at 120 C (1).

Even so, for people wondering whether they aredestroying the B12 in their fortified foods by cooking,

http://www.veganhealth.org/b12/intro#LTVhttp://www.veganhealth.org/b12/vegansources#fn13http://www.veganhealth.org/b12/vegansources#fn1http://www.veganhealth.org/b12/intro#LTVhttp://www.veganhealth.org/b12/vegansources#fn13http://www.veganhealth.org/b12/vegansources#fn1

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we do not have enough evidence to know for certain,so it is safest to make sure you rely on uncookedsources of vitamin B12.

Multivitamins

There are some concerns about vegans relying solelyon multivitamins that contain only small amounts ofB12 (less than about 25 g):

Herbert et al. (2) (1982, USA) reported that vitaminsB1, B3, C, and E, and copper and iron can damage

B12. They tested 15 multivitamin preparationsused daily by approximately 100 millionAmericans for inactive B12 analogues and allpreparations contained some (6-27% of totalcorrinoids).

Vitamin C in doses of 500 mg or more taken withmeals or within one hour after a meal, may

diminish B12 availability or destroy the B12 (3). Many multivitamins cannot be chewed, which is

important for B12 absorption in some people.That said, if a multivitamin is chewable and has 25 gof B12 (as cyanocobalamin) or more, and taken daily,it is most likely adequate.

Safety of Supplements

In 1988, Herbert cautioned that large amounts of B12may eventually be found to be harmful (4). Incontrast, Hathcock & Troendle (5) (1991) point outthat there appears to be little or no question that B12intakes of 500-1000 g/day are safe. The Institute of

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Medicine has not set an Upper Tolerable Limit for adaily vitamin B12 intake.

The cobalt and the cyanide contribution of 1000

g/day of cyanocobalamin are consideredtoxicologically insignificant (5). People with chronickidney failure, cyanide metabolism defects, andprobably smokersshould take a different form of B12.

Chewing or Swallowing Whole

Crane et al. (6) (1994, USA) noted that tablets of one

vitamin company dissolved slowly in water and acid.They then conducted a study to see if vegan patientswho had not previously responded to oral B12 tabletsswallowed whole could improve their B12 response bychewing the tablets. 7 people chewed the tablets of100 g (once a week for 6 weeks) and their averageserum B12 levels went from 116 to 291. Of the 9 whodidn't chew, theirs increased from 123 to only 139.

(However, a 100 g dose once a week is not a lot ofB12. The more surprising result of this experimentwas the large increase in the serum B12 of the 7people who chewed the tablets, not the small increaseof those who did not chew.)

7 of these 9 then chewed 500 g/day for 10 days andtheir levels rose to normal with a final average of 524

235. Three participants could not raise their levelsorally and required B12 injections to maintain serumB12 above 300.

A 2003 study compared 500 g per day via thesublingual (under the tongue) and oral routes. The

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results were that sublingual was no better than oralB12 at raising vitamin B12 levels or improving B12activity (as measured by homocysteine andmethylmalonic acid levels). Both routes increasedvitamin B12 levels effectively (12).

Oral B12 for People with Malabsorption

Some recent studies have shown that taking largeamounts of oral B12 can normalize B12 status even inpeople with pernicious anemia. For more information,see Oral B12 for People with Malabsorption inHow Recommendations Were Formulated.

Light

B12 supplements should not be left in the light asprolonged light damages cyanocobalamin (7, 8)

Non-cyanocobalamin Supplements

In addition to cyanocobalamin, there are oralsupplements available for methylcobalamin,adenosylcobalamin (known in the supplement industryas dibencozide and coenzyme B12), and to a lesserextent, hydroxocobalamin. See Non-cyanocobalamin B12 Supplements. As mentionedabove, these forms of B12 may be preferable for

vegan smokers.

S-adenosylmethionine (aka SAM and SAMe) is anothersupplement that has received attention. It is found inthe homocysteine-methionine pathway, and somepeople think it may be relevant to B12 status in

http://www.veganhealth.org/b12/vegansources#fn12http://www.veganhealth.org/b12/formula#ORALhttp://www.veganhealth.org/b12/vegansources#fn7http://www.veganhealth.org/b12/vegansources#fn8http://www.veganhealth.org/b12/noncyanob12http://www.veganhealth.org/b12/noncyanob12http://www.veganhealth.org/b12/smokehttp://www.veganhealth.org/b12/vegansources#fn12http://www.veganhealth.org/b12/formula#ORALhttp://www.veganhealth.org/b12/vegansources#fn7http://www.veganhealth.org/b12/vegansources#fn8http://www.veganhealth.org/b12/noncyanob12http://www.veganhealth.org/b12/noncyanob12http://www.veganhealth.org/b12/smoke

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people who have been B12 deficient. More informationis in SAMe.

http://www.veganhealth.org/b12/samhttp://www.veganhealth.org/b12/sam