Archive for the ‘Vitamin B12’ Category

Fermented Foods and Vitamin B12

Monday, January 10th, 2011

Someone sent me this question below and I thought I’d clear it up for anyone else who is wondering:

You did not mention kimchee or sauerkraut in your list of erroneous sources of B12. I wonder if you have any information about these products.

To my knowledge, there is no fermented food that requires a B12-producing bacteria for its fermentation. Wherever there are large amounts of bacteria, the chances increase that some B12-producing bacteria could be in the mix. Although the chances might increase, it is still unlikely, especially where fecal contamination is not involved, that a food is going to have biologically significant amounts of vitamin B12. But I have not seen any studies on kimchee or sauerkraut.

What Should I Be Tested For?

Tuesday, November 30th, 2010

I am regularly asked by vegans what they should be tested for. Here is a run down:

Vitamin B12

As I say in Should I Get My B12 Status Tested?

Vegans do not need to get their homocysteine or B12 levels checked merely because they are vegan. Rather, being vegan means that you should get a regular, reliable source of vitamin B12 from fortified foods and/or supplements. (Though if you’ve gone a month or so without a reliable source of B12, you should replenish your stores as described in Step 1 of the Recommendations.)

About 2% of people do not absorb B12 well. While this has nothing to do with being vegan, it is nice to know if you are such a person. You will not be able to tell unless you first have a reliable source of B12 for at least a few weeks before your B12 level is checked. Additionally, there are specific tests that directly measure B12 absorption.

If you get your B12 level checked, please note that eating seaweeds can falsely inflate B12 levels. Methods for determining B12 levels do not distinguish between B12 and some inactive B12 analogues. Many seaweeds contain a variety of inactive B12 analogues. Someone who is eating large amounts of seaweed may have serum B12 levels well above normal, but much of it could be inactive B12 analogues.

Vitamin D

This is probably the one nutrient that vegans really can benefit from getting tested even if they do not have any symptoms of poor health.


The body keeps blood calcium levels relatively constant regardless of your diet, so getting calcium levels tested doesn’t tell you much of anything (other than that you are not seriously ill). Getting your bone mineral density tested is the best way to find out what shape your bones are in. I don’t necessarily recommend this, unless you have reason to believe you might have osteoporosis. I’ve said it many times before, but I’ll say it again – most vegans should drink calcium-fortified non-dairy milks (or other foods) or take a calcium supplement.


If you’re taking a DHA supplement, then you don’t need to be tested unless you suspect you’re having a cognition or other possible omega-3-related problem. Here are some testing companies.

There is a more common test that could shed some light on your EPA status—blood clotting time. Most doctors test for this routinely. If your blood is clotting too fast, you might be lacking EPA. I rarely hear from a vegan whose blood is clotting too fast.


If a doctor is going to draw blood, getting an iron panel to see if you have enough (or too much) iron is a good idea, especially for menstruating women.


There is no direct test for iodine. Like B12, it’s best to just make sure you’re getting enough (but not too much). Iodine deficiency (and excess) can lead to thyroid problems, so getting your thyroid tested would be an indirect indicator. Click here for more on iodine.

And that covers it for any routine nutrients to test for regarding the vegan diet.

B12, Homocysteine, and Alzheimer’s Disease: More Evidence

Monday, November 15th, 2010

An October 21, 2010 article in New Scientist, Low levels of vitamin B12 linked to Alzheimer’s, describes research that adds more evidence to the idea that high homocysteine and low B12 levels are associated with Alzheimer’s Disease.

More info at

Comments on Doug Graham’s B12 Statements

Friday, October 22nd, 2010

You might remember my August 23rd post about an article on, Response to: Vegan Vitamin B12 Deficiency is a Myth. I have been asked to respond to another article about B12 on, Dr. Doug Graham Part III: The Medical Model, the Hygienic Model and Supplements.

Some background on Dr. Doug Graham: He is a chiropractor who promotes a raw food diet that comprises of 80% carbohydrate, 10% fat, and 10% protein.

If you read the article, you might find that Dr. Graham has an unusual take on preventative medicine. He mocks the medical establishment by saying, “And so before you have B12 deficiency, let’s take those B12 supplements, prophylactically. Before you have a problem with too little salt in your diet, you better supplement with salt. Before you have high blood pressure symptoms, let’s treat you for high blood pressure now.”

People take salt supplements?

Yes, you should take B12 before you have (symptoms of) deficiency because taking B12 does no harm, while waiting until you have a deficiency of B12 could do long-term, permanent harm, possibly setting you up for a stroke or dementia (if you are mildly deficient for many years).

Later in the article, Dr. Graham is asked what someone should do if they develop B12 deficiency. He basically says that a B12 deficiency is not from a lack of dietary B12, but from people not absorbing B12. He claims that if you fast on nothing but water, your body will then be able to absorb B12. He says he has experienced people whose B12 levels return to normal three to four weeks after a fast (it’s not clear if the fast is three to four weeks, or some other length).

But where would the body get the B12 to absorb if you are not getting any in your diet?

Graham: “B12 is everywhere. It’s in the air. It’s in the mucus membranes of your nose. Every time you inhale, you’re breathing in B12; every time you swallow your own saliva, you’re swallowing B12.”

Why then, when someone has B12 deficiency, do their B12 levels increase and their deficiency symptoms go away, upon taking B12? If they cannot absorb it from swallowing their saliva or breathing, why can they absorb it when it comes in supplemental form?

One answer would be because there is so little in the air and saliva that the absorption mechanism has to be much more efficient. Perhaps. But a more elegant answer is because there is no B12 in the air or in saliva, whereas there actually is B12 in a supplement.

The idea that B12 is floating around in the air is pretty bizarre. But, I cannot say I have ever read a study where someone tested a batch of air for B12. Since B12 would settle to the ground due to its molecular weight being heavier than air, everything exposed to air should have some B12 in it, but many products tested for B12 show none. I think we can dismiss the B12-in-air theory.

What about saliva? It is possible that some people have B12-producing bacteria in their saliva. I have never seen saliva tested for vitamin B12, but it is a safe bet most people’s would have little if any. One way we can infer this is because when a person becomes vegan (without supplemental B12 or fortified foods), normally, their B12 levels start to drop, and continue to do so until they get a source of vitamin B12.

Graham: “[B12 deficiency] has been shown in every diet; there is a certain percentage of people who go B12 deficient. Whether you are vegan, vegetarian, raw fooder, or Standard American Diet, that percentage is the same.”

If you look at Table 1 in the chapter Vegan Adults of my article Vitamin B12: Are You Getting It, you will see that in the EPIC-Oxford study, 1 out of 250 omnivores had B12 deficiency, while 150 out of 250 vegans had B12 deficiency. You do the math.

Graham: “B12 deficiency was first discovered in carnivorous or what you would call “people who would eat anything” – kind of a diet. That’s where B12 was first discovered and treated.”

Yes, it is estimated that 2% of all people cannot absorb B12 in the normal way and that might account for the one omnivore in EPIC-Oxford who had B12 deficiency.

Graham: “But we do have to look at the reality that most grain products, especially those that are called “enriched grain products,” cereal, breads, and pasta, and whatnots, are typically enriched with B12.”

Most grain products are not enriched with vitamin B12. If you go to the grains section of (and no doubt many other sources), it says “Most refined grains are enriched. This means certain B vitamins (thiamin, riboflavin, niacin, folic acid) and iron are added back after processing.” No vitamin B12. I also checked the packaging on three different brands of pasta I have here at the house and none has B12 added; I’ve never seen one that does.

Graham: “What we call the normal level of B12 is based on testing people who are supplementing with B12 at every meal. This is an abnormally high level of B12 compared to the normal population or compared to a population which isn’t supplementing.”

B12 deficiency is not defined as below the average level of B12 in the population, but rather as the level below which red blood cells stop forming properly.

Back to the idea that Graham has experienced people who cured their B12 deficiency through fasting. If a doctor I respected came to me and said that he had fasted people with B12 deficiency and their levels returned to normal even though they had not supplemented or eaten B12-containing foods, my interest would be piqued. But Dr. Graham does not have a good track record when it comes to vitamin B12 claims and so I don’t see any reason to take his claim about fasting seriously. Maybe the people fasting didn’t completely trust such methods and took vitamin B12. Who knows?

In summary, I would suggest that people not risk the dangers of long-term, mild vitamin B12 deficiency based on believing ideas that might sound good, but have little to no evidence to support them.

B12 Recommendations for All Ages

Thursday, October 7th, 2010

Two people have recently asked me for B12 recommendations for children, so I created a table in which I extrapolated the adult recommendations to children.


You’ll notice a range in the table for both one and two doses per day; anywhere within that range will be a good amount to take to maximize B12 status. Note that the RDA is to prevent overt B12 deficiency, not to minimize homocysteine levels. My recommendations are intended to be enough B12 to minimize homocysteine.

Homocysteine Update

Tuesday, October 5th, 2010

2007 was the last time I updated the article, Mild B12 Deficiency: Elevated Homocysteine. Since then, a whole lot of research has been published on the topic, and a number of people have written me about some of those studies.

Today I finished rewriting the article. Despite the large amount of research, the article is now much shorter than it used to be, with the new stuff starting here.

A Quick Summary

Vegetarians and vegans who do not regularly supplement with vitamin B12 normally have elevated homocysteine levels which are linked to cardiovascular disease and dementia.

Research has shown that people with previously diagnosed cardiovascular disease who embark on treatment to lower homocysteine levels have a reduced risk of stroke (in some but not all studies), but there has been very little benefit for other cardiovascular diseases. It appears that except for stroke, once the damage has been done, lowering homocysteine will not do much to improve cardiovascular disease.

More importantly for vegans without cardiovascular disease, a marked decrease in the rate of stroke in the USA and Canada has paralleled the fortification of foods with folate indicating that damage from homocysteine can be prevented.

The Take-Home Message

If you are vegetarian or vegan, make sure you follow the recommendations for taking vitamin B12.


Response to: Vegan Vitamin B12 Deficiency is a Myth

Monday, August 23rd, 2010

On Saturday, August 21, published an article by Cindy Jones-Shoeman, Vegan Vitamin B12 Deficiency is a Myth.

The article starts out by saying that “nothing could be further from the truth” than the idea that vegans can suffer a B12 deficiency from their diet.

The article by Jones-Shoeman appears to be a rehashing of an old article (apparently from 2004 or earlier) by Vivian Vetrano, “Rethinking & Clarifying the Vitamin B12 Issue” which appears on the Rest of Your Life Retreat website:

Although Vetrano’s article is one of the most fanciful stories I’ve ever read about vitamin B12, it is rather detailed and I will only respond to the excerpts from the Jones-Shoeman article:

“According to Dr. Vivian V. Vetrano, vitamin B12 actually comes from coenzymes, which are already present in bacteria found on the human body (in and around the mouth, for example).”

Vitamin B12 does not come from co-enzymes, it is a co-enzyme. Bacteria do produce vitamin B12, but there is no proof that bacteria living in most people’s mouths produce active vitamin B12 or produce it in amounts large enough that it could prevent B12 deficiency. This is underlined by the fact that many vegans develop full-blown vitamin B12 deficiency, and in some cases permanent neurological damage, as can be seen here: In addition to those cases in the scientific journals, I have known many vegans who have suffered from B12 deficiency and cured it by supplementing with cyanocobalamin (the most stable form of vitamin B12).

About a dozen studies have correlated low vitamin B12 levels in vegans with elevated homocysteine levels. Elevated homocysteine levels have been linked to early death, primarily from cardiovascular disease, and Alzheimer’s Disease. More details on that are at

“In fact, vitamin B12 deficiency is often, according to Dr. Vetrano, a symptom of a larger problem; that is, it’s not caused from a poor diet but rather from deficiency diseases…”

While it is true that about 2% of the population has trouble absorbing vitamin B12, the vast majority of problems that have been seen in vegans have been caused by a low B12 intake, not from absorption problems.

“Vitamin B12 deficiency due to a vegan diet is simply a lie that finally needs to be put to rest.”

Unfortunately, this could not be further from the truth. The most common, serious damage that results from vitamin B12 deficiency is when a pregnant vegan who does not supplement has a baby who also does not get any B12 supplementation. Typically, around 6 months of age, the infant’s growth and neurological development ceases and then begins to regress. In many cases, such infants have sustained permanent brain damage.

Vitamin B12 deficiency among vegans is real and is not something to be flippant about. It is so important that a number of vegan health professionals and organizations have endorsed an open letter to the vegan community, What Every Vegan Should Know about Vitamin B12 ( This letter has been signed by The Vegan Society (UK), Vegan Outreach, and many members of the International Vegetarian Union science group.

10 µg B12 Not Enough

Thursday, May 27th, 2010

On March 6, I posted that in light of new research, I was raising the lower limit of my single-dose B12 supplement recommendations from 10 µg to 25 µg. This was an extrapolation, but I just came across some new research to reinforce this change. A study from India shows that 10 µg of B12 in one single dose per day was not enough to lower homocysteine to ideal levels.

Details here.

Thanks, Tom!

Aphanizomenon Flos-aquae: A Source of Vitamin B12?

Friday, April 30th, 2010

Dr. Michael Greger brought my attention to a paper published last year on the B12 activity of Aphanizomenon flos-aquae (also known as blue-green algae).

My write-up on the study is too long to post here, but it appears that Aphanizomenon flos-aquae might provide some vitamin B12 activity in humans. On the other hand, it did not succeed in lowering homocysteine to an ideal level whereas vitamin B12 supplements do succeed at doing so. At this time, it would be prudent not to rely on it for optimal health.

Click here for the entire update.

Vegan Essentials

Vitamin B12 Recommendations

Saturday, March 6th, 2010

I have changed my vitamin B12 recommendations.

A 2010 paper by Bor et al., showed that in healthy people aged 18-50, a vitamin B12 intake of 4 to 7 mcg/day was associated with the lowest methylmalonic acid and homocysteine levels (1). They reviewed other research from the past 10 years, primarily on older populations, that reinforces this finding.

My previous recommendations were 1.5 – 2.5 µg twice per day. I have changed that to 2.0 to 3.5 µg twice per day. For supplements, I raised the lower end of the range from 10 µg to 25 µg. The daily range is now 25 to 100 µg.

You can read an explanation of my recommendations here under Step 2.

1. Bor MV, von Castel-Roberts KM, Kauwell GP, Stabler SP, Allen RH, Maneval DR, Bailey LB, Nexo E. Daily intake of 4 to 7 microg dietary vitamin B-12 is associated with steady concentrations of vitamin B-12-related biomarkers in a healthy young population. Am J Clin Nutr. 2010 Mar;91(3):571-7.