It is commonly suggested that women take well over 1000 mg of calcium each day and about half as much magnesium to protect the bones. Here is more evidence that this is not the best advice: https://healthy.net/scr/column.asp?Id=630

A one-to-one ratio seems to make better sense. And traditional cultures with strong bones have not found the need to consume such high amounts of calcium.

Mike

1500mg 1:1 calcium/magnesium from citrate.
More if you are over 40, smoke, or don't take dairy.
** lots of leafy green vegetables = less supplementation.