Eggcellent question! The answer, in an eggshell, is that you can eat eggshells. They are mostly calcium carbonate, and calcium is a nutrient that we need for strong bones and teeth.
But before you get cracking, bear in mind bacteria can live in eggs, and on their shells. Bacteria like salmonella enteritidis can make people sick. They can cause fever, diarrhea and stomach cramps. Most people experience these symptoms 12 to 72 hours after eating an infected egg. These microbes may be present in eggs that are raw or undercooked. Some studies suggest boiling eggshells in water for 30 minutes should make them safe to eat.
Eggshells have sharp pointy edges that make them uncomfortable to chew and swallow. Some companies sell eggshells as nutritional supplements. They grind them up into a fine powder to make it easier to add to your food.
Are you eggcited about the thought of eating an eggshell? Eggs are good for you even if you don't eat the shell. No yolking around, they are a good source of protein, vitamins, iron and other minerals. Be sure to cook them properly!
Image source: "Saving Eggshells" by Melinda Young Stuart is licensed under CC BY-NC-ND 2.0.