Calcium is a mineral that the body needs for numerous functions, including building and maintaining bones and teeth, blood clotting, the transmission of nerve impulses, and the regulation of the heart's rhythm. Ninety-nine percent of the calcium in the human body is stored in the bones and teeth. The remaining 1 percent is found in the blood and other tissues.
Where do we get calcium?
The body gets the calcium it needs in two ways. One is by eating foods that contain calcium. good sources include dairy products, which have the highest concentration per serving of highly absorbable calcium, and dark leafy greens or dried beans, which have varying amounts of absorbable calcium.
The other way the body gets calcium is by pulling it from bones. This happens when blood levels of calcium drop too low, usually when it's been a while since having eaten a meal containing calcium. Ideally, the calcium that is "borrowed" from the bones will be replaced at a later point. But, this doesn't always happen. Most important, this payback can't be accomplished simply by eating more calcium.
Calcium rich products
Oranges , Cauliflower, Milk, Milk products, Spinach, Dates and Cereals.