Hard question! Nobody knows for sure, but approximations are possible. The magical 1000 mg come from omnivore eating. If you reduce the intake of proteins and phosphates, you need less. There is data on tradional living bantu tribes, who have an intake of only 300 mg per day, but their diet is extremely low in protein. Spinach contains quite a lot, but the body can't use much of it as it is bound to the huge content of oxalic acid. Other greens will provide more calcium. Don't quit eating spinach as it tastes good and contains lots of other goodies.
Vegans need less Ca than lacto-(ovo)-vegetarians, who need less than omnivores; exceptions possible (people drinking liters of soda-pops for instance, as these contain lots of ortho-phosphoric acid). If you're around the 1000 mg, most probably you're more than on the safe side.
Vegans need less Ca than lacto-(ovo)-vegetarians, who need less than omnivores; exceptions possible (people drinking liters of soda-pops for instance, as these contain lots of ortho-phosphoric acid). If you're around the 1000 mg, most probably you're more than on the safe side.
