Eggshells are a cheap and effective source of calcium. They can be turned into eggshell powder at home and used as a calcium supplement. Calcium is important for bone health, and eggshell powder has been shown to be well absorbed by the body. Studies suggest that eggshell powder may help improve bone strength, especially in people with osteoporosis. To make eggshell powder, boil the eggshells to kill bacteria, dry them, and then grind them into a fine powder. You can add this powder to your food or mix it with water. However, it’s important to discuss with a healthcare professional before starting any new supplement.