Most people know that calcium is needed for building and maintaining bones and teeth. Whew, that's a lot of work for a little mineral. The calcium that does all this work circulates in the blood, and the body regulates the level of blood calcium very carefully. Extra calcium is stored in the bones, where it can be released quickly if the levels of calcium in the blood drops too low. Despite its importance, calcium is available in significant amounts from very few foods.
Most people think of dairy products as sources of calcium.
Milk, yogurt, hard cheeses, and cottage cheese are excellent sources, but not all sources of dairy products are good sources of calcium. For example, butter, sour cream and cream cheese contain minimal amounts of the mineral. Non-dairy sources of calcium include broccoli, dark green leafy vegetables, tofu, beans, peas, lentils and canned fish with soft edible bones. As you get older, your body's ability to absorb nutrients declines, so you need to take more calcium. On the other hand, too much calcium in your diet can result in hypercalcemia, an excessive build-up of calcium in the bones and some tissues such as the kidneys.