People whose parents have a history of fractures also seem to have reduced bone mass and may be at risk for fractures. An inadequate supply of calcium over the lifetime is thought to play a significant role in contributing to the development of osteoporosis. Many published studies show that low calcium intakes appear to be associated with low bone mass, rapid bone loss, and high fracture rates. National nutrition surveys have shown that many people consume less than half the amount of calcium recommended to build and maintain healthy bones. Depending upon how much calcium you get each day from food, you may need to take a calcium supplement.
Calcium needs change during one's lifetime.
The body's demand for calcium is greater during childhood and adolescence, when the skeleton is growing rapidly, and during pregnancy and breastfeeding. Postmenopausal women and older men also need to consume more calcium. This may be caused by inadequate amounts of vitamin D, which is necessary for intestinal absorption of calcium. Also, as you age, your body becomes less efficient at absorbing calcium and other nutrients. Older adults also are more likely to have chronic medical problems and to use medications that may impair calcium absorption.