Many Americans eat less than half the amount of calcium essential to developing and maintaining healthy bones, cautions the National Institutes of Health. The amount of calcium you need is based on many factors, including age, current regimen of medication, gender and a bone mineral density reading. In general, people need between 1,000 and 1,500 mg of calcium daily, according to the University of Michigan Health System. Sources of calcium come from both the animal and vegetable kingdom.
Calcium-Fortified Foods

Calcium-fortified foods offer a good way to increase calcium intake, advises the University of Illinois McKinley Medical Center. Manufacturers add calcium content to food products that are not calcium-rich. These fortified products include fruit juice, cereal, fruit drink mixes, frozen waffles and soy milk. Phrasing on the package including "calcium-fortified" and "excellent source of calcium" indicate the product contains more than 200 mg of calcium per serving. If the words "good source of calcium" appear on the package, it provides 110 to 190 mg per serving. Vegetarians and vegans should research the source of the calcium to avoid accidentally consuming animal products

Dairy Products

Dairy products offer the richest dietary source of calcium, according to the University of Maryland Medical Center. Drinking an 8-oz. glass of milk with your meal or snack adds about 300 mg of calcium. Cheddar, Swiss, gouda, ricotta, feta and all other cheese made from cow, sheep and goat's milk fall under the umbrella of dairy products. One ounce of mozzarella cheese contains 207 mg of calcium, a ¼ cup of ricotta cheese contains 168 mg of calcium and 1 tbsp. of parmesan cheese contains 69 mg of calcium. Two slices of Swiss or cheddar cheese contain an amount of calcium about equal to a glass of milk. Other dairy products commonly found in U.S. supermarkets are cream cheese, sour cream, yogurt and buttermilk.