Just look up "bone broth" on google, and you'll find a number of articles telling you why bone broth is the shit. It's easy, delicious, and so good for you.
I've personally noticed that when I drink bone broth, my DH is way better (DH stands for dermatitis herpitiformis, an autoimmune disorder related to celiac disease in which your skin gets all fucked up).
I went to my local grocer, and I buy bones. You can also use leftover bones from animals you've eaten and make bone broth from that too. These bones were specifically intended to make bone broth. It should be really cheap.
Put the bones in a pot, and cover with water. Boil it for about an hour. Add salt to taste. You can also add fresh herbs, like rosemary or sage, and it will be delicious.
If you're using cooked bones, let's say in the case where you are using the bones from a whole chicken you've cooked, you can only really use the bones once. When you use raw bones, like I did above, you can use them twice because more marrow will come out the second time.
Mineral content varied based on the species of animal and diet of the animal. Organic, grass fed bones will provide better mineral content than conventional cow bones, but it's still good for you even if you're eating conventional animals.
I think it's kind of interesting how in American society, we're raised to think we should eat chicken soup and eat jello when we're sick. Gelatin was actually a remedy for leaky gut and a number of other illnesses before medicine became an industry of corporate greed. (I swear I'm not opinionated). Interestingly, gelatin is amazing for you, but Cambell's chicken soup certainly is lacking in gelatin, and I haven't even mentioned the shit they put in their products. Make your own damn broth!
