The main component of bone that gives it strength is calcium phosphate. While calcium gives bones strength, collagen is the ingredient that gives bones flexibility. Bone cells replace damaged bone so that they stay strong and healthy.
Bone formation occurs while a person is growing. Because of this, bones grow rapidly in size and strength during childhood and into puberty with little bone loss. When a person reaches the age of 20, bone formation and bone loss tend to even out. At age 30, bone loss occurs more frequently than bone formation.
The three factors needed to keep bones strong are calcium, weight-bearing exercise and vitamin D. Because calcium is crucial for the development and maintenance of bone strength, it is important to eat and drink foods and beverages high in calcium or to take calcium supplements. Bone loss in some older people can lead to osteoporosis. It is also important to take vitamin D as well as to begin an exercise regimen in adolescence and maintain that regimen through the adult years. Postmenopausal women are especially at risk for bone loss. Women can lose up to 20 percent of bone density in their later years as their estrogen levels drop.