<<there is something secreted by the intestine called intrinsic
factor,
without which no amount of the vitamin can be absorbed or utilized by
the
body>>

<<Could something like this also cause problems in even being able to
tolerate
taking a supplement? [The calcium supplements] all made me sick, weak
and
faint.


Patti,

Intrinsic factor is required for the absorption of vitamin B12
primarily.
It's not required for the absorption of other nutrients.

Its not unusual to be sensitive to supplements.  In fact, taking them
may
make your health worse if your sensitive.  You might try a liquid
calcium/magnesium supplement.  If that doesn't work,  just focus on
calcium/magnesium rich foods.

Rob