On B12: (from a discusiion on another last from about a year ago)

> But the B12 producing bacteria live quite at the end of our
> colon where we're not able to absorb anymore; I havve not met
> any serious NH Practitioner yet who doubts this!
B12 producing bacteria are located throughout a healthy human digestive
tract, which includes the mouth, and small intestine too.  And these are
located where the B12 can actualy be absorbed and in some instances havs
been shown to be adequate to maintain B12 status.  We have a few
examples in the literature of healthy vegans who have practiced the diet
for over 13 years or more without supplelemnts and show adequate B12
status.

Alberts MJ, Nathan VI, Baker SJ.  Vitamin B12 synthesis by human small
intestine bacteria.  Nature (London) 1980;283:781-782.

Kapadia CR, Mathan VI, Baker SJ.  Free intrinsic factor in the small
intestine in man.  GAstroenterology.  1976;70:704-706.

Gastroenterology.  1972;62:11-21.  Bacterial flora of the GI tract in S.
Indian control subjects and pts with tropical sprue.

NEJM, 1959;260:575-580.  Serum and tissue concentration of Vit B12 in
certain pathological states.

Am J Clin Nutr.  1970;23:249-255.  Veganism:Clinincal findings and
investigations.

We maintain a very efficient enterohepatic circulation of B12 which
reabsorbs the majority of our  B12.    The main thing that interferes
with this process or the production of B12 and intrinsic factor is an
unhealthy digestive flora.  Raw, plant foods have been shown to be most
beneficial in establishing healthy GI flora.

B12 is alround us in our food, soil, water and even in the air and
rainwater.  All these can also contribute significant amounts to our
daily intake. 95% of all cases of B12 defeciancy are caused by a lack of
IF and not a lack of B12.  It is a metabolic problem and not a
deficiency problem and happens amongst the non-vegan population mostly.
There are just a few actually documented cases of B12 defeciency amongst
vegans, thought they do exist.  And as many practtitioners will tell
you, we do see it show up in ind. clinical cases every now and then. I
just finished helping resotore normal levels in 2 longterm vegans whose
levels had dropped dramamtically over the last 5-7 years.

Some think the increase is due to the increase in vegans.  I personally
think the increase is for several reasons 1) we look for it more and are
more conscious to check for it so we will naturally see it more.  2) Our
population, even the vegetarians, pure vegetarians, and assorted
categories of vegans still consume WAY to many processed, refined and
cooked foods, all of which cause detriment and harm to the GI
environment and flora.  3) it will show up more as our population ages
and manifests the results of our current 20th century experiments in
drug use (pharmaceutical and recreational), especialy antibiotics and
birth control and surgery.

Jeff

====================

> the B12-discussion is much more important, because it asks the major
> question: is mankind able to live strictly, his whole life,
> without any animal food ??

It is best for someone to follow a healthy and simple, unrefined, plant
diet that is mostly or all raw.

Regardless of whether or not they include animal products, and whether
or not these are raw or cooked, is not as improtant as that if they are
included, that they should make up only a small part of the intake.
Maybe between 1-5% at most.

And then if one is to have any serious doubts about their B12 level,
just go and get a simple blood test.  And in a few years, go and get
another one.  It is better to know then to guess.

> And B12 is an animal product or a
> bacteria product!

It is produced strictly by bacteria.   In our current system of
classification bacteria are classified under the heading Animal.
So vitamin B12 is the result of bacterial production, which is by its
strictest definition is an animal source.

Jeff

=====================

> I'm sorry that I haven't found enough to explain exactly what's
> the chemical
> difference between these two (or more) forms of B12.

Vitamin B12 is considered a generic term for a group of compounds called
"corrinoids" because of their corrin nucleus.  The corrin is a
macrocyclic ring made up of four reduced pyrrole rings linked together.
The corrin of vitamin B12 has an atom of cobalt in the center of it to
which is attached at almost right angles a nucleotide,
5,6-dimethylbenzimidazole.  Also attached to the cobalt atom in the VIt
B12 is one of the following:

-CN = Cyanocobalamin
-OH = Hydroxocobalamin
-H2O = Aquocobalamin
-NO2 = Nitrotocobalamin
-CH3 = Methylcobalamin
5'deoxyadenosyl = 5'deoxyadenosilcobalamin

Only 2 of the cobalamins, 5'deoxyadenosilcobalamin, and methylcobalamin
are active as coenzymes for humans.  However, the human body does have
the capacity to convert most of the other cobalamins into an active
coenzyme form of the vitamin.

Commercially available Vit B12 supplements contain cyanocobalamin which
has a cyanide molecule attached to the cobalt that stabilizes the
vitamin.  This form is converted to the metabolically active  form of
vitamin B12 in the body by the removal of the cyanide.

The term analog is used to refer to the nonactive forms.  They can
interfere with the absorbtion of active B12 by blocking its absorbtion.

Jeff

==================


> So which of the two cobalamins are found in plants?  And
> what is the best known plant source for B12?

It has not yet been conclusively demonstrated that ANY plants contain
B12.  And whether or not it is from contamnation of the soil, manure or
rainwater or not.

But here is the lowdown.

Sea vegetables, algae and spirulina, greens, grains, legumes have all
been reported to contain B12.  It has even been found in tobacco.
(Don;t tell RJR or Phillip Morris) :)

J Nutr.  1958;67:623-634

Br Med J 1977;2:1991 (Letter)

Lancet  1988;1:242-243

J Food Sci  1977;52:493-494

As I said it has also been found in rainwater:

Nature   1968;219:617-618

However, several other analysis found most of these plant foods
contained no B12. Only tiny amounts were found in barley malt syrup,
sourdough bread, parsley and shitake mushrooms. Only the spirulina and
alage had any appreciable amounts but these were later shown to be
mostly analogs.

Lancet  1988;1:242-243

The root nodules of legumes can be inhibited by B12 producing bacteria
and may produce active B12.

Ann Rev Nutr  1982;2:343-369

Even in all these cases, the original source of B12 is bacteria.  And
these bacteria do live in human GI tracts and can (may?) be able to
suppy you with an adequate amount.  Remember this is also a major source
of Vit K in humans.  The problem with B12 may be with a lowered fundtion
of our GI tracts and poor internal environment.

Jeff