From: russ@wpg.com (Russell Lawrence)
Subject: B12.  Was: talk.politics.animals
Organization: WP Group
Distribution: usa
Date: Thu, 15 Oct 1992 08:27:05 GMT


Martin Hulsey:
mh> My claim that vegan dietary regimens are *fundamentally deficient* 
mh> in vitamin B12, and *require* supplementation IS well-founded, and 
mh> supported by the peer-reviewed references that I have already 
mh> provided.

Russell Lawrence writes....
rl> Yet there are millions of healthy, traditional vegans who do not suffer 
rl> deficiency diseases.  Why?

From article <1992Oct15.023723.10669@athena.cs.uga.edu>, by hulsey@athena.cs.uga.edu (Martin Hulsey):
mh> How do you know that they are not deficient?  Did someone make 
mh> clinical measurement on each and every one?  ...

Probably not.  Would it be reasonable to assume, in advance, that an
apparently healthy vegan is really unhealthy unless proven otherwise?

Let me begin by pointing out that I'm not discouraging vegans from
taking B12 supplements nor am I encouraging vegans to "eat dirt".
While you may think otherwise, you're hardly qualified to read my
mind.

Here are the references that I have at hand:

From Boyle, A (MS, RD) and Whitney, E (PhD, RD).  _Personal Nutrition_,  
West Publishing Company, 1989.
    
	 Although people who abruptly stop eating animal products may
	 develop B12 deficiencies, traditional vegans usually have normal
	 B12 status.  Researchers have wondered why, since by definition
	 vegans eat no foods from animal sources.  Many hypotheses have
	 been advanced to account for this finding.  Perhaps vegans'
	 intestinal bacteria produce vitamin B12 for them to absorb.
	 Perhaps they continually reabsorb the B12 they have.  Perhaps
	 they ingest bacteria containing the vitamin with their food
	 or drinking water.  It appears that some plant foods do provide
	 significant amounts of vitamin B12 --- among them soybeans,
	 mung beans, mung bean sprouts, comfrey leaves, peas, whole wheat,
	 ground nuts, lettuce, and alfalfa.  Why they contain the vitamin
	 is not known; perhaps in some cases bacteria in their roots 
	 make the vitamin and the plants then translocate it to their
	 edible parts.  Source: Immerman, AM.  "Vitamin B-12 status on 
	 a vegetarian diet: a critical review". _World Review of Nutrition 
	 and Dietetics_, V37:p38-54, 1981. 

Herbert, Victor.  "Folic Acid and Vitamin B12".  Shils, Maurice, 
ed.  _Modern Nutrition in Health and Disease_, Lea & Febiger: 
Philadelphia, 1980.  

    "The sole source of B12 in nature is synthesis by microorganisms.
	  The vitamin is not found in plants except when they are 
	  contaminated by microorganisms.  Fruits, vegetables, and grain
	  products are usually devoid of B12.  However, the root nodules
	  (PhD, of certain legumes contain microorganisms that make B12 and
	  unwashed vegetable products may also contain B12 because of
	  contamination by soil or fecal matter.  These small amounts of
	  B12 in legumes and contaminated food may provide the only
	  dietary source of B12 for strict vegetarians."

Williams, S. (PhD, MPH, RD)  _Essentials of Nutrition and Diet 
Therapy_, 5th ed.  Times-Mirror:Boston, 1990. p 144

	 "[B12] occurs as a protein complex in foods, so its food
	  sources are mainly of animal origin.  The ultimate source,
	  however, may be designated as the synthesizing bacteria
	  in the intestinal tract of herbivorous animals.  Some 
	  synthesis is done by human intestinal bacteria".

mh> If a "traditional" vegan (whatever that means) is truly healthy, 
mh> I would say that it is because he/she takes vitamin supplements 
mh> or eats foods fortified with B12.  

Perhaps, but most traditional vegans live in countries where such
supplements may not be readily available.  In any case, isn't it
unscientific for you to tell us, in advance, that a healthy vegan
must be consuming supplements?  Surely there must be at least
one vegan, somewhere in the world, who doesn't conform to the
preconceived "idee fixe" that's revealed by your fondness for the
distinctly unscientific expression, "bambiphillic".

rl> My statement was based on a paper
rl> by Victor Herbert stating that soil is an excellent source of B12, and
rl> that soil contamination may well explain why traditional vegans do not 
rl> typically suffer B12 deficiency diseases.

mh> If you know of a Herbert paper that says this, why can't you give the 
mh> reference?  This is one reason why I consider you irritating.
mh> 
mh> I checked all 200 of Herbert's citations (MESZ) just now, and 
mh> found no reference to "soil."  Was this suggestion in Vegetarian 
mh> Times or some such reference by chance?

See above.

> ...
rl> I asked you to explain where gorillas and orangs obtain their supply
rl> of B12, yet you've responded by describing Goodall's observations of 
rl> chimps.  Surely you're not expecting us to believe that the diets of 
rl> chimps and gorillas and orangs are identical.  

mh> Are you now suggesting that chimpanzees would represent a special 
mh> exception to your dirt eating theory?  The diets of primates are 
mh> identical only in the sense that they are more accurately considered 
mh> omnivores rather than vegans.  I never suggested otherwise.

Precisely how much meat do you think "omnivores" like gorillas and 
orangs consume each day in order to get the supply of B12 that you 
consider necessary?  

>... [insults deleted]

rl> Let me repeat the question that you've failed to answer satisfactorily:
rl>
rl>       Where do gorillas and orangs get their B12?
rl> 
rl> In a previous article, you seemed to be saying that we should accept
rl> the RDA specified by the Food and Nutrition Board of the National 
rl> Academy of Sciences (3 micrograms/day) as the "scientific" requirement, 
rl> in spite of the fact that many nutritionists (notably Herbert) 
rl> consider 1 microgram to be quite sufficient:
rl> 
rl>    "This amount (3 micrograms) is much higher than the intake of 
rl>     millions of healthy vegetarians, is associated with gradually 
rl>     increasing body stores each decade of life and, for this and 
rl>     other reasons, it was reduced to 2 micrograms/day by the 
rl>     1980-1985 RDA Committee.  The joint FAO/WHO Expert Group 
rl>     recommended in 1987 a daily intake of 1 microgram of vitamin B12 
rl>     for the normal adult..."   See Herbert, Victor.  "Folic Acid and 
rl>     Vitamin B12".  Shils, Maurice, ed.  _Modern Nutrition in Health 
rl>     and Disease_, Lea & Febiger: Philadelphia, 1980.  
rl>
rl> For the sake of consistency, however, let's assume that a gorilla 
rl> weighing 600lb would require proportionately more B12 than a 
rl> human weighing 200 lbs.  Since a 100 gram portion of raw beef 
rl> contains 2.65 micrograms of B12, it doesn't seem unreasonable to 
rl> assume that a 600lb gorilla would be required to consume 339 
rl> grams of beef/day in order to obtain roughly 9 micrograms of B12.  
rl> Gee, that's nearly 12 ounces of meat a day.  Yikes!  
rl> 
rl> I'm not an expert on gorillas, but I have skimmed through Dian 
rl> Fossey's book and don't recall any reported observations that 
rl> would lead us to believe that gorillas have this kind of taste 
rl> for meat.  

mh> In 1990, the RDA for B12 was revised downward from 3 mcg/day, 
mh> though not to Herbert's satisfaction.  Your gorilla calculations 
mh> are therefore in error in addition to being irrelevant.  

So the new figure is 2 micrograms per day?   Would this imply that
a 600 lb gorilla would need to consume 8 ounces of meat per day
in order to have normal B12 status?   Please explain. 

-- 
Russell Lawrence, WP Group, New Orleans (504) 443-5000
russ@wpg.com   uunet!wpg!russ