Jerry:
>confirms my point, Indian Vegetarians are not Vegans, they are lacto
>vegetarians, and as such drink and use milk, which in England has
>antibiotics in it which inhibits the production of B12 in the colon, the
>same would apply to most Iranian vegetarians. All vegans are vegetarians,
>but not all vegetarians are vegan, only about 1/3 and most of us westerners

I doubt that Iranian dairy farmers use a lot of antibiotics, and I assume
that British vegetarians go to great efforts to get high quality milk not
contaminated with antibiotics.  I see no evidence that the body produces
B12 but do believe that the antibiotics could interfere with the production
of intrinsic factor without which the body cannot absorb B12.  Below you
will find excerpts from the British Vegan Society's information sheet on
B12 which can be found in its full length at

http://www.vegansociety.com/info/info16.html

Another interesting url on B12 is a message posted to raw-food Nov. 21,
1997 by Jeffrey S. Novick <[log in to unmask]>:

http://maelstrom.stjohns.edu/CGI/wa.exe?A2=ind9711&L=raw-food&P=R5619

>From the UK Vegan Society:

"Vitamin B12 can be stored in the liver, which normally contains sufficient
(2-5 milligrams) for a period of 3-6 years, even in the total absence of a
food source. For this reason, although official recommendations are
expressed as a daily amount, it is not actually necessary to consume the
vitamin every day. A regular intake, at least three times a week, is
adequate. Furthermore, our bodies do recycle the vitamin from the bile as
it passes through the small intestine. The vitamin is also conserved in the
kidneys. At times of lower dietary intake of B12, its rate of absorption
from food into the bloodstream rises, thus maximising available supplies."

"Active B12 & Analogues:  Measuring the B12 content of foods is complicated
by the active B12 and related substances (analogues) which resemble the
vitamin. For many years, it was thought that edible seaweeds, fermented
soya foods and spirulina contained high levels of B12. The amount of B12 in
these foods was measured using bacterial growth as an indicator and it
measured a whole family of 'chemical look-alikes'. A newer test, called a
differential radioassay, is thought to specifically measure the forms of
the vitamin which the body can use. Re-analysis by this newer method of
testing indicates much lower levels of B12 in many foods e.g. tempeh, which
was believed to contain several micrograms of B12 per 4 ounce portion, was
found on re-analysis to contain virtually no active vitamin(1)(3)."

"Grains, nuts, pulses, vegetables and other natural plant foods do not
contain B12, unless they are contaminated with B12-producing bacteria from
the soil. Vegans using lightly-washed home-grown produce may obtain useful
amounts of the vitamin in this way. In the 1950s a research investigated
why a group of Iranian vegans did not develop B12 deficiency (1). He
discovered that they grew their vegetables in human manure, did not wash
them carefully, and thus obtained the vitamin from bacterial contamination.
Some drinking water may also contain B12."

"There is also some evidence that bacteria in our intestines make B12 which
our bodies can use. Adequate active B12 is produced by intestinal bacteria
but generally in the colon, where it cannot be absorbed, rather than higher
up in the small intestine. In some people, B12-producing bacteria certainly
exist in the small intestine where the vitamin manufactured can, in theory
at least, be absorbed. Exactly what contribution this makes to the daily
B12 intake of vegans remains to be clarified."

1) Herbert, V. (1988). Vitamin B12: plant sources, requirements, and assay.
Am. J. Clin. Nutr. 48:852-858.
2) Herbert, V., Drivas, G., Foscaldi, R., Manusselis, C., Colman, N.,
Kanazawa, S., Das, K., Gelernt, M., Herzlich, B. & Jennings, J. (1982).
Multivitamin/mineral food supplements containing vitamin  B12 may also
contain analogues of vitamin B12. New Engl. J. Med. 307:255-256.
3)Herbert, V., Drivas, G., Manusselis, C., Mackler, B., Eng, J. & Schwartz,
E. (1984). Are colon bacteria a major source of cobalamin analogues in
human tissues? 24-hour human stool contains only about 5ug of cobalamin but
about 100ug of apparent analogue (and 200ug of folate). Trans. Assoc. Am.
Physiol. 97:161-171.

Comment: I find it interesting that Victor Herbert is used as the main
reference.  From the above it is clear to me that vegans who do not eat
foods or supplements fortified with B12 or unwashed produce do risk running
into deficiencies.  This is confirmed by the fact that most vegans do eat
fortified foods/supplements as recommended by virtually all authorities in
the vegan movement.  I see no indications that vegans have fewer problems
with intrinsic factor than those on other health oriented diets.

Best, Peter
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