What proportion of adult bone mass is typically acquired by age 20 in boys?

By age 20, typically about 90% of adult bone mass is acquired in boys. This period is crucial for bone development, which generally occurs rapidly during childhood and adolescence. The majority of bone mass is accumulated during these formative years, influenced by factors such as nutrition, physical activity, and hormonal changes.

The attainment of bone mass is vital for reducing the risk of osteoporosis and fractures later in life. By age 20, boys have usually reached a significant proportion of their peak bone mass, which is an essential foundation for skeletal health. After this age, although bone remodeling continues, the ability to build new bone diminishes, highlighting why the age of 20 is considered pivotal in assessing bone density and health later in life.