From: altar@beaufort.sfu.ca (Ted Wayn Altar)
Subject: B-12 deficiency & recommendations
Keywords: B-12
Organization: Simon Fraser University, Burnaby, B.C., Canada
Date: Sun, 26 Jul 1992 18:46:16 GMT

 
It would seem that interest in this topic of B-12 is quite
extensive, which is probably a good thing since this is probably
the most widely held up "disadvantage" with a vegan diet, a diet
that is otherwise so wholesome and advantageous in every other
way.  Maybe because it is the only apparent "flaw" of a vegan
diet that so much fuss is made about it.  Indeed, much wailing an
gnashing of incisors by our omnivorous critics is something all
vegans must contend with and patiently tolerate.  :-(
 
 
A.  SYMPTOMS OF B-12 DEFICIENCY
 
Too often the descriptions of symptoms in some reference texts is
drawn from information written from the perspective of medical
practitioners who have access to test results and who are going
to rely heavily on such results.  For us lesser mortals, all we
have is our own experiential (phenomenological) "feel" of
wellness or not.  This is not to be discounted since it is such
feelings of a `lack of wellness' that brings us to seek medical
advice in the first place, or motivates us make important life
changes.
 
Susan Starrett's description of her own situation nicely provided
a concrete illustration and I want to thank her for her
information and experiential self-description.
 
For another practical, non-laboratory symptomatology of B-12
deficiency, the following by Thrash & Trash (1982) is quite good:
 
     "The pernicious anemia patient was first described in the
     medical literature in 1849 as one who appeared pale and
     sallow with a shiny tongue and complained of weakness and
     fatigue that progressed gradually to the point of paralysis.
     Blood tests done on such patients today would reveal low
     hemoglobin levels and large, pale red blood cells.  In the
     early stages of the illness there are numbness and tingling
     in the hands and feet with a loss of sensation.  Gradually a
     lack of motor coordination develops.  These symptoms are now
     known to be due to an inability to synthesize myelin, the
     fatty sheath that insulates nerve fibers.  As a result, the
     nerves to the limbs degenerate.  If allowed to proceed
     unchecked, the deterioration progresses into the spinal cord
     and ultimately to the brain.  Moodiness, poor memory, and
     confusion give way gradually to delusions, hallucinations,
     and overt psychosis."
 
Now, with respect to the psychological/psychiatric symptoms, the
following might be of some use, albeit it is more jargonistic:
 
     "Psychiatric symptoms attributable to vitamin B-12
     deficiency have been described for decades. The earlier
     reports are for the most part in accord with more recent
     ones, despite being diagnostically less specific in
     psychiatric and hematologic terms. These symptoms seem to
     fall into several clinically separate categories: slow
     cerebration; confusion; memory changes; delirium, with or
     without hallucinations and/or delusions; depression; acute
     psychotic states; and (more rarely) reversible manic and
     schizophreniform states.
               From Hector & Burton (1988)
 
Note that we are talking about what APPEARS to be schizophrenic
states, but of course we don't have here true schizophrenia,
hence the term "schizophreniform states".
 
No doubt, some of our defensive omnivorous critics might think in
their meaner moments that this mental deterioration describes all
of us vegetarians.  :-)
 
 
CAUSE FOR PANIC?
 
Let it again be said, however, that B-12 deficiency is "rare"
among vegans and that over 95% of deficiency problems are NOT due
to a simple intake inadequacy but are due to an MALABSORPTION
problem.  The development of a serious B-12 deficiency is not a
simple or well understood matter but it is known that absorption
and conservation of B-12 in the body is more important than how
much is to be found in the diet.
 
Known causes of malabsorption are a lack of intrinsic factor
(e.g., due to pernicious anemia, destruction of gastric mucosa,
etc.), removal or disease of the second portion of the ileum,
competition for B-12 by microorganisms or intestinal parasites,
toxic substances, etc.
 
Beside malabsorption, there are also possible problems (see
Herbert, 1973) in UTILIZATION (e.g., enzyme deficiencies, liver
or kidney disease, etc), INCREASE LOSS (e.g., renal disease) or
for an INCREASE REQUIREMENT (e.g., hyperthyroidism, lactose
intolerance).
 
Still, if one has an absorption, loss, or increase need problem,
then presumably when little B-12 is available in the diet then
still less is going to be assimilated.  Now, what can we do to
prevent a B-12 deficiency?
 
 
PRACTICAL RECOMMENDATIONS:
 
1.  REDUCE ONE'S NEED FOR B-12:
 
Before we consider increasing our intake of B-12 via supplements
we should first consider minimizing those conditions that might
make for an unusual requirement of large quantities.  Assuming
that one is in normal health (e.g., no intestinal parasites,
etc.), then below are some of the lifestyle conditions that can
unduly increase one's need for B-12 (adapted from Thrush &
Thrush, 1982):
 
     1.  The body can become habituated to large quantities of
          vitamin B-12.  Hence, some caution about megadoses of
          B-12 should be considered.
     2. Meat or other animal products and refined carbohydrates
          (sugars) when used generously may more than double B-12
          needs.
     3.  Persons who use drugs, chemical, or beverages which
          destroy B-12 (e.g., tobacco, alcohol, caffeine, etc.)
     4.  Megadoses of vitamin C may produce B-12 deficiency by
          destroying the cobalamins during transport through the
          gastrointestinal tract (Hines, 1975).  Quantities more
          than 1/2 of a gram can destroy 50% to 95% of B-12 in
          the food.
     5.  Oral contraceptives are used (affects the B-12 binders
          of the blood).
     6.  egg albumin and egg yolk decrease B-12 absorption
     
     
2.  INCREASE NATURALLY OCCURRING B-12 IN THE DIET.
 
Fresh garden pricked vegetables, particularly root vegetables,
that are not overly scrubbed cleaned or pealed will have some B-
12 on their surface.  Boiling such vegetables and then throwing
out the water would make for a loss of this B-12.
 
Since B-12 is predominantly produced by bacteria (no animal
produces its own), then foods grown in soils where the bacteria
flora is rich would presumable have more B-12 on their surface.
Hence, organically grown foods will probably be richer in B-12.
 
There is now some recent evidence (Combs, 1991) that some peas
and bean actually produce their own B-12.  It was previously
thought that the only source in nature was bacteria.  This would
suggest that such peas and beans would have their B-12 throughout
rather than just on the surface.  Still, this probably will not
suffice as a single plant source to provide sufficient B-12.
 
A simply but useful recommendation is to chew one's food properly
and leave plenty of time between meals helps absorption.  The R-
binders in saliva help to hold onto the B-12 in the food until it
reaches the small intestine where it absorbed (Fleming, 1978).
 
 
3.  TAKING SUPPLEMENTS.
 
MULTIVITAMIN preparations containing B-12 is probably NOT a good
idea.  Besides consuming so-called vitamin "D" which most people
do not need and which has been implicated in helping to cause
arteriosclerosis and osteoporosis, these preparations contain
breakdown products of B-12 that can actually have an anti-B-12
effect.  Hence, these multivitamins may contribute to the very
deficiency that they were supposed to correct.  Victor Herbert
(1962), the leading authority on B-12, reported that all of the
10 multivitamin-mineral products that he tested showed anit-B-12
breakdown products.  Tests for B-12 in the blood unfortunately
cannot discriminate between the true vitamin B-12 and its
breakdown products.
 
For healthy adult vegans I do think we should be careful about
recommending routine B-12 supplements.  Even though complete
absorption is not likely, the dosages are probably still too high
(1200 mcg).  There is some case studies and experimental evidence
that an excessive B-12 consumption encourages cell division in
general and certain tumor cells in particular (Bergevin et al,
1976; Chauvergne, 1970).
 
If I may here voice a more personal opinion, I do think we should
be cautious and hesitant about over-consuming vitamins.  There
are no miracle foods or pills that can undo a sedentary life, bad
living habits and a junk food or fatty diet.  I find it sad to
see people spending so much money on vitamin pills and yet
begrudging a few pennies to buy fresh fruit or oganic produce.
Also, there is this misplaced notion that if a little works or is
good for you, then more is automatically better.  Our society as
a whole is badly skewed by this over-rating of quantity over
quality.
 
Frankly, I think that if one is in good health and eats quality
foods, then vitamins are simply not necessary and are a waste of
money.  The only benefit of popping multivitamin pills for most
healthy vegetarians, I suspect, is simply its placebo effect and
the enjoyment of seeing one's urine turn a brilliant yellow.
Having said this, however, there are exceptions, like  B-12 for
vegans and iron supplements for vegan women.  This does not
entail that all vegans MUST take these supplements, only that
there are common circumstances where they are most advisable.
 
In general, use of B-12 supplements should be considered by
pregnant and lactating women, young infants and children, the
elderly and vegans not in good health or who still smoke.  Serum
levels of B-12 are lower for smokers than non-smokers (this may
be an effect of the cyanide content of tobacco smoke, which the
body attempts to detoxify by a means that unfortunately uses up
the stores of B-12).
 
Non-smoking, healthy adult vegans who eat sensibly, are not on
medications (e.g., antibiotics) and who do not daily drink
alcohol probably do not need to take supplements.  If such vegans
are going to take supplements, then they should probably not take
them on regular basis since the doses are too high.  Remember,
individuals even on conventional diets (diets high in fat and
animal protein which increase the need for B-12) still only need
about .1 mcg per day according to Victor Herbert (recent revision
of RDA recommendations has lowered the amount from 3 mcg/day to 2
mcg/day).  Maybe half of a 1000 mcg pill no more than once month
would be more than sufficient.  Finally, make sure that your
supplements are derived from bacteria cultures and do not contain
spirulina or nori.
 
If one has been a vegan for a many years, it might be a good idea
to have one's serum B-12 levels checked.  The normal range is
about 150-750 pg/ml according to the Merck manual.  Others put it
at 140-900 pg/ml.  There is no exact cutoff.  Vegans, of course,
will have levels at the low end but this by itself is not a cause
for alarm.  After all, the "normal" range is based upon research
from an omnivorous population and vegans do have a lower need for
B-12 and are more efficient at preservation of extant stores.
Indeed, it could be argued that the "true normal" range might
well closer to that of vegans.  The ideal physiological
functioning has yet to be determined, but we do know that almost
all investigators reporting on vegans report them as being above
average in health and more active.  :-)
 
 
                                             ted
 
References:
 
I've already listed some of my primary sources in a previous
posting.  I have here drawn most heavily upon Thrash & Thrash
1982 and Combs (1991).  For further information about B-12 I
would highly recommend these books.  I would also recommend Keith
Akers (1989) chapter on B-12.  While the Thrash & Thrash book is
now 10 years old, it is at least written from perspective of two
MD's who are practicing vegetarians.  The Combs text is the
single best advanced book on vitamins that I have seen, although
it may be overly technical for most readers (as maybe all books
are at this level of scholarship).
 
Thrash & Thrash (1982).  NUTRITION FOR VEGETARIANS, 1982.
 
Combs, Gerald (1991).  VITAMINS: THEIR ROLE IN NUTRITION &
     HEALTH.
 
Akers, Keith (1989).  A VEGETARIAN SOURCEBOOK: THE NUTRITION,
     ECOLOGY, AND ETHICS OF A NATURAL FOODS DIET.
 
Hector & Burton (1988).  What are the psychiatric manifestations
     of vitamin B-12 deficiency?  JOURNAL OF THE AMERICAN
     GERIATRICS SOCIETY.  36(12):1105-12,
 
Hines, J. (1975).  Ascorbic acid and vitamin B-12 deficiency.  J.
     OF AMER. MED. ASSOC., 234(1):24.
 
Herbert, V. (1973).  The five possible causes of all nutrient
     deficiency: Illustrated by deficiencies of vitamin B-12 and
     folic acid.  AMER. J. OF CLIN. NUTRITION, 26:77.
 
Herbert, V. (1962).  Harmful B-12 breakdown products in
     multivitamins?  MEDICAL WORLD NEWS, (Sept. 28):12-13.
 
Bergevin et al, (1976).  Pernicious anemia terminating in acute
     myeloblastic leukemia.  SOUTHERN MEDICAL JOURNAL, 69:110.
 
Chauvergne, J.  (1970).  The risk of administering vitamin B-12
     to cancer patients.  SEMAINE DES HOSPITEAUX PARIS 46:2170
 
Fleming, A. (1978).  Serum vitamin B-12 levels and vitamin B-12
     binding proteins of serum and saliva of healthry Nigerians
     and Europeans.  AMERICAN J. OF CLIN. NUTRITION, 31:1732.