December 3, 2008
Bones play many roles in the body. They provide structure, protect organs, anchor muscles, and store calcium. Adequate calcium consumption and weight bearing physical activity build strong bones, optimizes bone mass, and may reduce the risk of osteoporosis later in life.
Peak bone mass refers to the genetic potential for bone density. By the age of 20, the average woman has acquired most of her skeletal mass. A large decline in bone mass occurs in older adults, increasing the risk of osteoporosis. For women this occurs around the time of menopause.
It is important for young girls to reach their peak bone mass in order to maintain bone health throughout life. A person with high bone mass as a young adult will be more likely to have a higher bone mass later in life. Inadequate calcium consumption and physical activity early on could result in a failure to achieve peak bone mass in adulthood.
Osteoporosis or "porous bone" is a disease of the skeletal system characterized by low bone mass and deterioration of bone tissue. Osteoporosis leads to an increase risk of bone fractures typically in the wrist, hip, and spine.
While men and women of all ages and ethnicities can develop osteoporosis, some of the risk factors for osteoporosis include those who are
Calcium is a mineral needed by the body for healthy bones, teeth, and proper function of the heart, muscles, and nerves. The body cannot produce calcium; therefore, it must be absorbed through food. Good sources of calcium include
Recommended amount of calcium vary for individuals. Below is a table of adequate intakes as outlined by the National Academy of Science.
|Recommended Calcium Intakes|
|6 months-1 year||270|
|70 or older||1200|
|Pregnant & Lactating||1000|
|Source: Dietary Reference Intakes for Calcium, National Academy of Sciences, 1997|
Vitamin D also plays an important role in healthy bone development. Vitamin D helps in the absorption of calcium (this is why milk is fortified with vitamin D).
For more information on calcium and children visit the National Institute of Child Health and Human Development (NICHD).
Regular physical activity has been associated with many positive health benefits including strong bones. Like proper calcium consumption, adequate weight-bearing physical activity early in life is important in reaching peak bone mass. Weight-bearing physical activities cause muscles and bones to work against gravity. Some examples of weight bearing physical activities include
Incorporating weight-bearing physical activity into an exercise plan is a great way to keep bones healthy and meet physical activity recommendations set forth in the Dietary Guidelines for Americans.
Adults: Engage in at least 30 minutes of moderate physical activity [on] most, preferably all, days of the week
Children: Engage in at least 60 minutes of moderate physical activity [on] most, preferably all, days of the week
For more information, visit Dietary Guidelines for Americans.
Powerful Bones. Powerful Girls.TM site for Girls
This girl-friendly Web site helps girls understand how weight-bearing physical activity and calcium can be a fun and important part of everyday life.
Also available for Parents.
Bone Health and Osteoporosis: A Surgeon General's Report
By 2020, one in two Americans aged 50 years or older will be at risk for fractures from osteoporosis or low bone mass.
* Links to non-Federal organizations found at this site are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. CDC is not responsible for the content of the individual organization Web pages found at these links.