Are you male, by any chance?
If you are, then take extra heed of jespah's warning re. kidney stones.
Why? Because if you do go silly and pile in tons of calcium over a period of time, as sure as eggs is eggs you WILL get one or more kidney stones.
The only way I can describe the feeling a male gets when passing one of these buggers, is something akin to giving birth to a particularly spiny cactus through one's penis.
And that's just the final stage of actually expelling the thing. First of all, you have the sickeming dull but excrutiating gripes whilst the bugger works its way down one of your miniscule internal tubey bits.
It's like the pain that woman experiences whilst giving birth, apparently, but without all the stirrups, or the unneccesary screaming and fuss.