Generously high in calcium, here is another simple DIY anyone can do.

Quite easily, in just three steps.

1. Hard Boil the eggs. At least 15-20 mins (sometimes I overboiled by about 10 mins as I am very busy elsewhere). Pictured in the collage above are shells from nine (9) eggs.
2. Peel and oven bake for 20-30 minutes.
3. Use coffee grinder. Blend a few seconds at a time to a fine level.
4. Store. Done.

To recap ~ the RDI / recommended daily intake is 1,000 mg minimum for adults,  1,200mg for pregnant women (though this can be raised to 2,000 miligrams or 2 grams). For older adults 50 years over, this increases to 1,300 mg (gender-agnostic).

Just one (1) whole egg shell (presuming it is a "large"classification type), equates to two (2) grams of net calcium amount. However, 800 mg of this is considered the elemental weight. This translates to around one (1) teaspoon of powder representing one (1) whole egg.

Storage wise, so long as it is kept dry and in "cool" temperature, they can be stored up to a month. Since I'd usually prioritise calcium intake from dairy (actual food calories there + a little more Vit D and K, plus proteins and fats) I'd freeze the egg powder instead and =use them supplementally.

Other Trivias.

So what's in the egg shell? Well, firstly - the calcium. It's calcium carbonate, specifically (CACO3).

Not a lot of other salts though ~ sulfur, potassium, zinc, manganese iron and copper were reported. Apparently very small amount, not even close to approaching one % of weight in general, except sulfur 2.3 to 3.5% (dry vs boiled hen egg shell, respectively).

Boiling the eggs just for 10 minutes, then followed by about 20 minutes for further cooking (the egg shells further), seem sufficient to eliminate all pathogens (Bartter J et al. 2018). 

It is not exactly solid or completely enclosed per se. Instead, tiny pores ranging from 9,000 on average per egg is proclaimed from one source, and another all the way to 17,000. Thus, to prevent oxidation (simply from air exposure) obviously - it's important to store them in the fridge.

How to use?

Sprinkle them as is throughout all foods.

Does it have a taste? Not really. At least from what I have incorporated over the years. It's not something you would ever take by the spoonful amounts.

It does have a distinct "powdery smell" that might bother some people. Put them in the fridge, closed tightly. Use as needed, problem solved.

Live-It-Forward,

AW.