Hi Robert,
It is good to hear from you again. Thanks for your interesting post on
calcium excretion in elevated protein consumption.
>
>And did the Paleodiet, probably high in animal protein, cause osteoporosis?

It is difficult to reconcile the results from the study you cite with the
archaeological data suggesting reduced bone mineralization after the advent
of agriculture (and presumably reduced protein consumption) in various
cultures.

>
>Question: how much of protein is catabolized to energy?  The calcium loss was
>only significant after adjustments for other variables in the elderly
Japanese
>(50-79 yo subjects.)  Their muscle mass is probably lower than younger
people,
>who would use more protein to maintain lean mass.

Yet the following report was conducted on young women, and produced similar
results:
 Ball D, Blood and urine acid-base status of premenopausal omnivorous and
vegetarian women.
Br J Nutr. 1997 Nov; 78(5): 683-693.

best wishes,
Ron Hoggan