Calcium can be obtained from foods naturally rich in calcium such as dairy foods, from calcium-fortified foods and beverages, from supplements or from a combination of these. Recognition of calcium's many health benefits, along with Americans' low calcium intake, has led to interest in how best to meet calcium needs.
Foods are the preferred source of calcium.
In addition, these foods provide substantial amounts of other essential nutrients. Consequently, intake of dairy foods improves the overall nutritional quality of the diet. Other foods such as some green leafy vegetables, legumes and cereals provide calcium, but generally in lower amounts per serving than do dairy foods. Also, some components such as phytates in cereals and oxalates in spinach reduce the bioavailability of calcium. Calcium-fortified foods and calcium supplements are an option for individuals who cannot meet their calcium needs from foods naturally containing this mineral.