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Eggshell Calcium Powder

Eggshells can be sterilized, ground and used as a highly available source of calcium in your pet's diet. Containing trace minerals that are important in bone mineralization, eggshells are a great and inexpensive calcium alternative to bone meal or limestone. This tutorial will demonstrate how to enter eggshell calcium powder into the Food Wizard. Preparation and storage methods are also briefly discussed.


To sterilize the eggshells, place them in boiling water for 15-20 minutes, a process known as pasteurization, which kills most bacteria, according to the American Egg Board. A rolling boil, at 212 degrees Fahrenheit (100 degrees Celsius), falls well above the 160 degrees Fahrenheit (71.1 degrees Celsius) recommended by the USDA Food Inspection and Safety Service for safe egg consumption. Boiling separates the membrane, which you can them scoop out as floating solids along with the foamy ring that will form.

Once you boil the eggshells long enough to kill any bacteria, oven-dry them at 140 degrees Fahrenheit (60 degrees Celsius) in a single layer on a cookie sheet for an hour. Use a coffee grinder for best results when making eggshell powder for your pets, as the resulting particles are finer in texture and easier to mix into liquids or solids. Sometimes you have to use a sifter to separate the larger particles from the finer powder. You can run these larger particles through the coffee grinder a second time.


Although it does not address the use of eggshells for calcium, the USDA Food Safety and Inspection Service recommends using anything containing eggs or egg products within three to four days of initial preparation. Store eggshell powder in a sealed container in the refrigerator between 40 degrees Fahrenheit (4 degrees Celsius) and zero degrees (-18 degrees Celsius) for longer storage, especially after removing the membrane during the pasteurization process. 


Below we have a series of screenshots that show the values that we enter into the Food Wizard. Open the Food Wizard and start entering the values as shown.

Choose to enter values for 100 grams in the Food Wizard.

Name = Calcium Eggshell Powder

Food Energy = 0 kcal

Calcium = 40,100 mg
Phosphorus = 99 mg
Magnesium = 450 mg

Iron = 2,240 mcg
Copper = 770 mcg
Zinc = 513 mcg

Selenium = 2.4 mcg

Step 1 - Add Common Measure

The image below shows the first tab in the Food Wizard. For this tutorial we are entering the exact values that will appear in the database. Choose the Per 100 grams button.

Step 1 - Add Common Measure

Step 2 - Food Name

The image below shows the second tab in the Food Wizard. The only required value that you have to enter in this tab is the name of the food or supplement. We also enter some common names to help us when searching for this supplement later.

Step 2 - Food Name

Step 3 - Macronutrients

The image below shows the third tab in the Food Wizard. We don't have enough information, so we enter zero for Food Energy and leave all the other values empty.

Step 3 - Macronutrients

Step 4 - Amino Acids

The image below shows the fourth tab in the Food Wizard. Since the amino acids are negligible, we leave this tab blank.

Step 4 - Amino Acids

Step 5 - Fatty Acids

The image below shows the fifth tab in the Food Wizard. Since the fatty acids are negligible, we leave this tab blank.

Step 5 - Fatty Acids

Step 6 - Minerals

The image below shows the sixth tab in the Food Wizard. Enter the values exactly as they are listed here. Pay attention to Iron, Copper, Zinc, and Selenium which are listed in micrograms (mcg).

Step 6 - Minerals

Step 7 - Vitamins

The image below shows the seventh, and final, tab in the Food Wizard. There are no vitamins to list so leave this tab empty.

Step 7 - Vitamins


That's it! We press the SAVE & CLOSE button on the ribbon and all the values are converted and stored in the database as 100 grams of Eggshell Calcium Powder. Next we will show our new food / supplement in the Foods module. Click on the FOODS button on the ribbon to open up the Foods module.

Looking at our newly entered food

With the Foods module open, enter "Eggshell" in the search textbox and click the FIND button. With the Eggshell Calcium Powder entry highlighted, click on the EDIT button on the ribbon to see our newly entered values.

Searching for Eggshell in Foods module.
Detail View showing values for eggshell powder that are stored in the database.

Additional Notes

The composition of eggshell is very similar to bones and teeth. There are about 27 trace elements found in eggshell. We only list the most important or largest amount for our purposes, which is to use eggshell as a calcium source. There is widely varying information on the nutrient composition of eggshells. We examined many sources and chose the source(s) with the greatest likelihood of scientific accuracy.


I used the following sources to prepare this eggshell calcium tutorial blog.

1.  A. Schaafsma, I. Pakan, G.J.H. Hofstede, F.A.J. Muskiet, E. Van Der Veer, Mineral, and P.J.F. De Vries, Amino Acid, and Hormonal Composition of Chicken Eggshell Powder and the Evaluation of its Use in Human Nutrition, 2000 Poultry Science 79:1833–1838. This is an excellent review of the nutrient composition of chicken eggshell powder and the source of the data we use for this tutorial. This publication can be found here.

2.Mohammad Aminul and Masahide Nishibori, Use of extruded eggshell as a calcium source substituting limestone or oyster shell in the diet of laying hens, Vet Med Sci. 2021 Sep; 7(5): 1948–1958. This article can be found here.

3. NutritionData, egg shell 1/2 teaspoon. The calcium data listed on this website represents the calcium salt (calcium carbonate) and not elemental calcium. We do not use this data because we cannot trust the accuracy of any of the mineral values. This web page (and web site) have been removed from the internet.

4. Dan Wich, Using eggshells as a source of calcium. This is a good tutorial for making eggshell calcium powder. The web page can be found here.

5. Gary D. Butcher and Richard Miles, Concepts of Eggshell Quality, Veterinary Medicine-Large Animal Clinical Sciences Department, UF/IFAS Extension. Good review on factors affecting eggshell quality and size. This publication can be found here.

6. Maxwell T. Hincke, Yves Nys, Joel Gautron, Marc McKee, The eggshell: structure, composition and mineralization, PubMed (January 2012). Fantastic review on the composition of avian and reptile eggshells. This publication can be found here.

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