Tubular bone does contain a lot of calcium.
This is beyond doubt, because the calcium contained in bones accounts for more than 90% of all calcium in animals. However, this kind of calcium belongs to biological calcium, and our usual cooking methods can't separate calcium from bones and be absorbed by human body, because in order to make human body absorb calcium, it is necessary to convert those calcium into ionic form.
There is no way to supplement calcium to the body by drinking soup cooked with bone.
In fact, this statement is not absolute, and the usual cooking methods may boil out 2% calcium content in bones. But it is definitely not what people in rumors drink to decide. Even if the cooking time is prolonged or even the bone mass is increased, there is no obvious effect. Instead of spending a lot of time cooking bone soup and spending a lot of money on stewing those bones, it is better to drink more milk and eat more soybeans, which is more direct.
Some people say that vinegar can be added to bone soup to separate bones from calcium. If you don't add vinegar, the calcium in your pot of bone soup may only account for 1% of milk. Even with vinegar, the calcium content in it is only 4% of that in milk. Instead of swigging bone soup and gnawing at bones without any meat, it is better to take the money to the market, buy more pork belly and lean meat, and then buy a box of milk.
Why do some people mistakenly think that drinking bone soup can supplement calcium?
This is because the boiled bone soup is white and looks like it contains a lot of calcium. In fact, this is only because the meat in the bone is separated from the bone through long-term boiling, so that the fat in the meat is dissolved in the soup, and the fat dissolved in the soup becomes some thin fat drops, and the color looks very white after being wrapped by protein. Therefore, those bone soups that are mistakenly thought to contain a lot of protein are actually bone soups that contain a lot of fat. And the fatter you are, the more you will give people a taste, a pure feeling. So don't give children a lot of bone soup when they are very young, or when the elderly can't digest well. Drinking too much may make the elderly eat more fat, which may lead to an increase in blood pressure, while drinking too much bone soup for children may lead to obesity.
So how to supplement calcium?
You can drink more yogurt and eat a little cheese in your life. These are excellent foods for supplementing calcium. You can eat two soybeans and nuts when you are free. Besides, those dark green vegetables are high in calcium. Moreover, vegetables contain vitamins that can promote gastrointestinal peristalsis, and some trace elements contained in them can promote the absorption and utilization of calcium by the human body. Therefore, people should have scientific methods of food, clothing, housing and transportation, and don't blindly listen to some old people's remedies.