Archive for the ‘Vitamin B12’ Category

B12 & Iron Deficiency in an Italian Vegan Infant

Tuesday, June 26th, 2012

Sadly, a report was published today of a vegan mother in Italy whose infant developed B12 deficiency and the typical neurological issues that go along with it.

The mother had taken a multivitamin with 2.5 µg of B12 during her 2nd and 3rd trimester. The baby had been born small (3rd percentile for weight). He was then exclusively breast fed and the mother ceased the multivitamin.

The infant developed both B12 and iron deficiency by five months. Seven months of treatment with B12 and iron resulted in drastic improvement in neurological symptoms, but not a full recovery at that time.

The case underscores the need for exclusively nursing mothers to ensure they have a reliable source of vitamin B12 so that their breast milk has adequate amounts. A baby should be born with iron stores to last 6 months, but this boy was not. Not much information was given about any attempts to monitor the mother’s iron levels during pregnancy or the baby’s after birth ― apparently not much was done.

I’m hoping for some better vegan health news as the week progresses…


Guez S, Chiarelli G, Menni F, Salera S, Principi N, Esposito S. Severe vitamin B12 deficiency in an exclusively breastfed 5-month-old Italian infant born to a mother receiving multivitamin supplementation during pregnancy. BMC Pediatr. 201 Jun 24;12(1):85. | link

More B12 Claims

Saturday, June 16th, 2012

An activist brought to my attention the article B12 Deficiencies in Vegans? Not True! at Flaming Vegan. I was surprised to read the article and the comments, and so I posted some comments of my own below it.

Another reader brought my attention to a page claiming that miso is a source of vitamin B12 and that chlorella is the “best source” of vitamin B12.

As for miso, the two published studies that have measured vitamin B12 in miso have found none. As for chlorella, two studies have found vitamin B12 in batches of chlorella while one study found practically none. Chlorella might be a source of vitamin B12, but there has yet to be any studies in the scientific literature to determine if chlorella can improve vitamin B12 status (see B12 in Tempeh, Seaweeds, Organic Produce, and Other Plant Foods for citations).

It is not clear why chlorella would have vitamin B12 – whether through contamination or because it actually produces it, and because of this, multiple batches from different locations should be tested before there is any certainty that it is a reliable source.

It should also be noted that the second link above lists romaine and arugula as sources of calcium. According to the USDA, one cup of shredded romaine has only 15 mg of calcium and one cup of arugula has 32 mg of calcium. So if you are going to rely on either for calcium, you will need to eat many servings.

Aloe Vera: Not a Source of Vitamin B12

Friday, April 13th, 2012

A reader told me that she has been seeing aloe vera talked about as a source of vitamin B12 recently. says, “Aloe vera is one of the only known natural vegetarian sources of Vitamin B12,…”

Sigh. It turns out that there have been a couple studies which show that aloe vera enhances the absorption of vitamin B12 for older people:

Yun JM, Singh S, Jialal R, Rockwood J, Jialal I, Devaraj S. A Randomized Placebo-Controlled Crossover trial of Aloe Vera on Bioavailability of Vitamins C and B(12), Blood Glucose, and Lipid Profile in Healthy Human Subjects. J Diet Suppl. 2010 Jun;7(2):145-53. | link

Devaraj, S., Patel, S., Jialal, R., Jialal, I. Aloe supplements enhance bioavailability of vitamin C and B12 in older adults. The FASEB Journal: Experimental Biology 2007 Abstracts 8.1-701.35. Washington, DC; April 28-May 2, 2007. | cited here

Of course, increasing absorption of B12 is not the same as actually containing it. (Please note that I don’t know anything about how to increase B12 absorption through the use of aloe vera.)

And, unsurprisingly, I couldn’t find anything on PubMed that would indicate aloe vera actually contains vitamin B12.


Clinical Trial of the Vegan Diet and B12

Friday, April 13th, 2012

A study from Poland was just released and I have added a summary to the Vegan Adults page of Vitamin B12: Are You Getting It?


“A group of 20 omnivores agreed to follow a vegan diet for 5 years. Half the group ate B12 fortified foods and the other half did not. Neither group took B12 supplements. The amount of B12 received via fortified foods was not measured. After 5 years, B12 levels in the group using fortified foods went from about 340 to 310 pg/ml. B12 levels went from about 290 to 220 pg/ml in the group not using fortified foods. Only two participants had B12 levels fall below 200 pg/ml, traditionally considered the cutoff for B12 deficiency, and they were both from the unfortified foods group.”

The most interesting finding of this study may be that they convinced 20 omnivores to go vegan for five years! They claimed that all 20 participants adhered to the diet.

I was also surprised that they conducted a study that was likely to induce a nutrient deficiency. They might have told the participants that if they started feeling the symptoms of B12 deficiency they should do something about it, but there appeared to be no monitoring between months 24 and 60.

The researchers did not measure homocysteine or methylmalonic acid levels at any point, so it is not clear what level of B12 deficiency these subjects actually had. There is reason to think that B12 levels as high as 400 pg/ml are required to minimize homocysteine, although this likely depends on how much folate someone gets as folate also reduces homocysteine.


MÄ…dry E, Lisowska A, Grebowiec P, Walkowiak J. The impact of vegan diet on B-12 status in healthy omnivores: five-year prospective study. Acta Sci Pol Technol Aliment. 2012 Apr 2;11(2):209-12. | link

Sublingual B12 no better than just swallowing

Friday, April 6th, 2012

Question (edited for clarity):

It is always explicitly recommended that Vitamin B12 tablets should be dissolved under the tongue (aka “sublingual”). I wonder if that is also true for other minerals and vitamins of special concern to vegetarians, such as iron and vitamin D2? If not, why is this the case with vitamin B12?


I have always told people who asked about sublingual B12 that there was no evidence, of which I was aware, that sublingual was any better than just chewing. Despite this, until today, I had been recommending sublingual in my Step 1 Recommendations, which are geared towards people who have not recently had a reliable source of B12. I have recommended sublingual as a precaution just in case it was more effective. In recent years, I have been more diligent about trying not to recommend anything just to be prudent unless specifically stating that is why I am recommending it. This suggestion for sublingual (versus just oral) was a remnant left over from previous times.

Still, I did not know whether sublingual was better than oral until I got this question and decided to check in on the research. As it turned out, there was a study as long ago as 2003. Yikes! I guess I hadn’t checked in quite a long time.

The 2003 study compared 500 µg per day via the sublingual and oral routes. The results were that sublingual was absolutely no better than oral B12 at raising vitamin B12 levels or improving B12 activity (as measured by homocysteine and methylmalonic acid levels). The report did not specifically state whether the tablets were chewed or not (I assume that they were swallowed whole). So now I’m not sure I should even suggest that the tablets be chewed, but because other studies have shown a benefit to chewing, I will leave that in my recommendations.

As for other vitamins and minerals, I have never checked into the research on taking them via the sublingual route, but my sense is that there would not be any benefit. It might even be dangerous to try this with iron given that it is a pro-oxidant and probably should not be held in constant contact with your tissues.


Sharabi A, Cohen E, Sulkes J, Garty M. Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. Br J Clin Pharmacol. 2003 Dec;56(6):635-8. | link

Coconut Water Kefir – Latest Unproven Source of Vitamin B12

Saturday, March 31st, 2012

[Update August 16, 2013: It appears I messed this up. Tonix was not claiming their product contains B12, only that the Lactobacillus and Bifidis in their product prodcuce B12. I have since learned that there is evidence that Lactobacillus produces B12 (see Lactobacillus species). There is evidence to suggest that vegans should not rely on Lactobacillus for keeping their vitamin B12 status healthy, but this company’s claims may very well be correct.]

To make a long story short, I recently became aware of a mainstream vegan who was relying on coconut kefir water for vitamin B12, and another vegan who did not immediately recognize the problems with this idea.

On their website, the company Tonix makes the following claim about their coconut water kefir:

“This product is brisling with Lactobacillus and Bifidobacteria, which creates awesome intestinal flora, digestion and production of B-6, B12, K, niacin and folic acid.”

I wrote them on March 6:

Someone brought it to my attention that Tonix claims that its coconut keifer contains vitamin B12. I see on your website that you say that Lactobacillus and Bifidobacteria are the source of vitamin B12. I’m writing to let you know that those bacteria do not produce vitamin B12 and that there is no reason to think that coconut keifer would contain vitamin B12.

If you are interested in more information on vitamin B12 in plant foods, please see this article:

I hope you will correct the information on your website and I look forward to your response.

I never heard back and the info is still up as of March 31, so I decided to publicly warn vegans about this claim.

B12 Follow-Up: Can a Natural Diet Require Supplements?

Wednesday, March 7th, 2012

Speaking of B12, I just updated Can a Natural Diet Require Supplements? The changes are so extensive that I decided to just link to the article rather than reproduce the changes here. I hope people who get, or have, this question about a vegan diet will find it helpful.

And please remember that you can support by buying things through the site’s links to, Barnes & Noble, and Pangea – the Vegan Store! This does make a difference for me and I am most grateful to those of you who continue to do this. Sharing my posts on Facebook and Twitter also makes a big difference and gets the word out about healthy vegan eating.

Thank you!

Reminder from Italy: Get B12!

Wednesday, March 7th, 2012

The good news is that we rarely hear reports such as this coming from the United States these days, so the word seems to have reached most vegans here. But a case report from Italy of a 36-year old vegan was just released. I have added it to Individual Cases of Deficiency of Vitamin B12: Are You Getting It? and reproduced here:

A 36-year-old woman developed numbness, tingling and sensory loss in her hands and feet, weakness in the lower limbs, and disequilibrium, with difficulty in writing, gait, walking up and down stairs, driving. She was a dance-master, and after 3 months she was not able to work. The patient was treated with intramuscular injections of cyanocobalamin. Oral vitamin D3 and calcium were also given. After 3 months, the patient reported paresthesias and gait improvement. Six months later, weakness, sensory disorders, and paresthesias had fully disappeared, and she reported that her skin got clearer and hair loss stopped. After 1 year, spinal cord MRI, nerve conduction studies, and somatosensory evoked potentials were normal. Neurological examination, 2 years from the onset, showed reduced vibration sense in the lower limbs and normal tendon reflexes.

I should add that it can be difficult to get the message about vegans and B12 to non-English speakers. Anyone should feel free to translate posts such as this and send them to vegetarian societies in non-English-speaking countries. You don’t even need to ask me for permission.

B12 Recommendations


De Rosa A, Rossi F, Lieto M, Bruno R, De Renzo A, Palma V, Quarantelli M, De Michele G. Subacute combined degeneration of the spinal cord in a vegan. Clin Neurol Neurosurg. 2012 Feb 6. | link

Safety of Cyanide in Cyanocobalamin

Wednesday, February 8th, 2012

Due to some articles going around the Internet, many people have written me asking whether vitamin B12 supplements in the form of cyanocobalamin are safe due to the cyanide content. Because so many people have asked, I have updated the page Side Effects of B12 Supplements of Vitamin B12: Are You Getting It? with the following information:

The safety of cyanocobalamin has raised concerns due to the fact that cyanide is a component of cyanocobalamin, and the cyanide molecule is removed from cyanocobalamin when used by the body’s cells. Cyanide is also found in many fruits and vegetables and so humans are always ingesting small amounts of cyanide, and like in most fruits and vegetables, the amount of cyanide in cyanocobalamin is considered to be physiologically insignificant.

According to the European Food Safety Authority, “Data of from a Norwegian dietary survey show that the average and high (97.5th percentile) daily intake of [cyanide] among consumers amounts to respectively 95 and 372 micrograms/person or 1.4 and 5.4 micrograms/kg bw/day (7).” The amount of cyanide in a 1,000 microgram cyanocobalamin is 20 micrograms.

Table 1 contains some additional numbers regarding cyanide amounts in cyanocobalamin for comparison purposes.

Table 1. Cyanide Content of Cyanocobalamin
molecular weight of vitamin B12 1,355 g/mol
molecular weight of cyanide 27 g/mol
Percentage of cyanide in vitamin B12 by weight 2.0%
Amount of cyanide in 1,000 micrograms of cyanocobalamin 20 micrograms
Minimal Risk Level for oral cyanide4, a 0.05 mg/kg of body weight per day
Minimal Risk Level for oral cyanide for 140 lb person 3,175 micrograms/day
Percentage of Minimal Risk Level in 1,000 micrograms of cyanocobalamin 0.6%
Lethal dose of cyanide5 0.5 to 3.0 mg/kg of body weight
Lower end of lethal dose of cyanide for 140 lb person 31,750 micrograms
Percentage of lethal dose in 1,000 micrograms of cyanocobalamin 0.06%
aMinimal Risk Level do not assess cancer risk (6).

In summary, the amount of cyanide in 1,000 micrograms of cyanocobalamin is about .6% of the amount that is thought to be the lower level that causes harm.


See Side Effects of B12 Supplements.

Thank you, Ginny, for sending some of the research!

B12 Status of Older Indian Vegetarians

Monday, November 21st, 2011

On Friday, a cross-sectional study was released from India examining the B12 status of apparently healthy people aged 60 and older (average age of 66 years). The study included both omnivores and vegetarians. Ninety-nine of the participants were vegetarian (presumably lacto-ovo) and 76 were omnivores.

There was significant exclusion criteria including cardiovascular disease as well as memory difficulties. The participants were from affluent areas.

Sixty-two of the participants were taking multivitamin supplements. They had significantly higher plasma B12, and lower methylmalonic acid (MMA)a and homocysteine (HCY)b levels. Only 2 people consuming supplements had higher than normal homocysteine levels.

61% of the vegetarians had elevated MMA levels vs. 46% of the omnivores. 17% of the vegetarians had homocysteine levels above 15 µmol/l vs. 7% of the omnivores.

There was no significant correlation between plasma B12, MMA, or HCY levels and any of the 10 cognitive tests given the subjects.

In summary, it appears these vegetarians could have been doing a bit more to improve their B12 status but so far no harm had come from their less-than-ideal levels. B12 supplements proved to be of value. Given that this was a cross-sectional study with stringent exclusion criteria, it may not be representative of the larger population.


aMethylmalonic acid (MMA) levels are a specific measure of vitamin B12 status. MMA is not thought to be harmful, particularly at slightly elevated levels.

bElevated homocysteine (HCY) is associated with low B12 and folate intakes and levels, as well as risk of early death, heart disease, stroke and dementia. More info at Mild B12 Deficiency – Elevated Homocysteine.


Shobha V, Tarey SD, Singh RG, Shetty P, Unni US, Srinivasan K, Kurpad AV. Vitamin B 12 deficiency & levels of metabolites in an apparently normal urban south Indian elderly population. Indian J Med Res. 2011 Oct;134(4):432-9.   |   Link