>Beth Bess wrote:
>
>>I had a disagreement with a vegan about the likelihood of a paleo-eater
>>getting a B12 deficiency. Have any of you ever heard of such happening?
>
On Tue, 1 Aug 2000 00:09:35 -0400, Don Wiss <[log in to unmask]> wrote:
>This makes no sense. B12 is in animal foods. How could a paleo-eater be
>deficient? Or is this a typo and you've asking about a B12 overdose?

Vitamin b12 is in a animal rich diet more than plentiful and there is no
danger of overdose.
Even a diet of very little animals contains probably enough B12, if we take
the big apes as a model, who eat only a few occasional insects.
1/2 l of milk has enough of b12 according to RDA.
Vitamin b12 is rare in vegan products, but it is in small amounts in
fermented products and grows on the surface of plants (wherefrom we wash it
away).
These small amounts are too few on the long run (long run is 5-15 years!).
B12 is synthesised in the gut of animals and humans and is uptaken and
available then in plants grown in soil fertilized with feces (human and of
course cows).

Your disagreement was probably based on the following:
If there is a noted vitamin b12 deficit, it is almost always *not*
by a dietary deficit (remember, reserves are gigantic), but from a disorder
in the reuptake machanism (lack of "intrinsic factor").
Vitamin b12 is used in digesting fluids and taken back in a later gut area.
This process is not 100% efficient , so normally a very tiny amount is lost
in the feces (about 1-5 ug per day, u meaning 1/1000000g).

The total b12 used daily is *much* higher but taken back.
If the reuptake mechanism  is damaged then verg big amounts of b12 are lost,
this happens to vegans as well as any neanderthal like eaters.
(then only injections work).

This explains, that meat eaters are equally endangered as vegans.
But vegans not paying special attention on the issue may experience
a tiredness (maybe of beeing vegan) after quite a long time (5-15 years).
Vitamin 12 is a vegan substance btw, because it is made only by bacteria,
not by animals.

Ok, now here comes my Vitamin b12 test results i got (they only could do a
serum test, but other blood cells parameters were ok).
I had 154ng per dl blood, with a range from 211 to 911 beeing normal.
Slightly below the "min" mark.
For the car i would refill the oil and so do i with b12.
I'll take 100 pills of 100 ug. Thats the requirement for 10000 days
(27 years, or at 5ug/day 5 years).

This after some 15 years eating plants and mushroom only *with* a little
dairy (only cheese and very little dairy fat). But the dairy part was *far*
from the 1/2 l milk needed for RDA.

I plan to repeat the exercise after 5 years.

Now I think about this case. Was my diet unnatural all the time, and in
which way?
Some essential was missing. Significant, even if it's the weakest demand of
any essential, i know of.

Eather man has adopted increased vitamin b12 dependency by meat consumption.
For the tiny amounts, even occasionally meat may be enough.

Or man, like the big apes (i'd assume a similar requirement for) is to eat
2-4% insects (certainly natural paleo).

Or man is to eat more plants with more unwashed surface?

Anyway I'll stick to refuelling every 5 years.

regards

Amadeus S.