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
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 increased 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:
- Post menopausal women
- Older adults
- Small in body size
- Eating a diet low in calcium
- Physically inactive
Calcium is a mineral needed by the body for healthy bones, teeth, and the 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:
- Dairy products: low fat or nonfat milk, cheese, and yogurt
- Dark green leafy vegetables: bok choy and broccoli
- Calcium-fortified foods: orange juice, cereal, bread, soy beverages, and tofu products
- Nuts: almonds
The recommended amount of calcium varies 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).