Calcium is very important for building and maintaining strong, healthy bones. The amount of calcium needed changes as a person grows older. Most Americans get only half the calcium they need from their diet.
The recommended daily calcium intake for adults ages 19 to 50 is 1,000 mg a day, increasing to 1,200 mg a day for adults older than 50. Calcium is found in many foods, including dairy products such as milk or yogurt. Most postmenopausal women should take calcium supplements, because they do not get sufficient amounts of calcium in their daily diets.
To increase your body's ability to absorb calcium, take calcium supplements with milk or with foods that contain vitamin D and phosphorus. Taking calcium without vitamin D probably is not beneficial.2
Avoid eating bran (such as bran cereals) at the same time as foods that are high in calcium. Bran decreases the amount of calcium absorbed by the body.
Citations
WebMD Medical Reference from Healthwise