This is an important comment from my wife, commonly referred to as my Handmaiden.
On the eggshell thing:
Wash the eggshells after putting the eggs in a pan.
Then save all your eggshells in a bag until you have enough.
Bake the eggshells at 350 for 20 min or so to kill any bacteria. Each eggshell contains approx. 1800-2000 mg calcium and 70-80 mg phosphorus.