View Full Version : B12: a research collection from ecologos/PubMed

May 16th, 2004, 11:18 AM
From http://www.ecologos.org/B-12.htm

"We frequently hear unsupported claims, like "B12 deficiency seems to be a problem on vegan diets."
Actually, no it doesn't. There are very rare, isolated, single cases here and there, but those have local causes, and are clearly not evidence of the global cause being a vegan diet.
A poll of 968 adults (=>18 years old) reported that 0.9% claimed to be true vegans. Since there are more than 209 million people in the US in that age range, there are about 2,000,000 vegans in the US.
So, if an insignificant 1% of all US vegans actually had B-12 issues, the medical journals would be flooded with reports of these 20,000 cases, yet we do not see them. If 10% of vegans had B-12 problems, where are the 200,000 cases??? Where are they? Even if 10% of vegans had B-12 problems, these could be easily solved with inexpensive supplements and thus allow this 10% to also reap the considerable and documented health benefits of plant-based diets!
A PubMed search for "B-12 deficiency vegan" brings up only 25 hits since 1967, less than one per year, and the journals abstracted in PubMed pretty much cover the entire civilized planet. Some of these abstracts report no B-12 problems!
PMID 8926531 indicates that for Japanese vegan children who consumed 2-4 grams of Nori per day: "Not a single case of symptoms due to B12 deficiency was found".
PMID 3913054 states: "Deficiencies have been described for vitamin D and B12 but the evidence is often unconvincing."
PMID 6272567 states: "No clinical signs of nutritional deficiency were observed in the vegans".
PMID 646250 states: "Possibly such malabsorption may also be present in many of those vegans developing overt vitamin-B12 deficiency in whom Schilling test findings have been normal.", indicating that the deficiency was not caused by dietary deficiency, but instead by intrinsic absorption problems. Meat-eaters also have B-12 deficiencies due to internal malabsorption problems.
Significantly, most of the studies that reported "deficiency" in vegans are based on blood tests that are evaluated against meat-eaters' blood profiles. That is as meaningful as claiming that vegans are "deficient" in serum cholesterol, serum fats, high blood pressure, BMI, heart attacks, strokes, and cancers compared to meat-eaters when, in fact, these lower numbers indicate a superior health status and lowered morbidity/mortality. Similarly, other false and biased "evidence" of "deficiency" is determined by comparing to meat-eaters' consumption of certain nutrients. This is misleading, perhaps intentionally so, since no one would claim a vegan diet is "deficient" in cholesterol or animal fat.
Thus, there doesn't seem to be a real vegan B-12 deficiency issue, especially when supplements are cheap and readily available.
Where is the evidence that there is a real B-12 problem caused by an intelligently-chosen vegan diet? "

If you go to this page, you'll find 20-30 studies on B12, most of them releveant to living on a vegan diet