Final answer:
Bone loss generally starts to outpace bone gain between 30 and 40 years, with a more rapid decline for women after 50 due to menopause and lower estrogen levels.
Step-by-step explanation:
Normally, bone loss will begin to exceed bone gain between the ages of 30 and 40 years. As individuals age, bone mass, which is a measure of the total amount of calcium and other minerals within the bones, usually reaches its peak around the age of 30. After reaching this peak, bone density begins to decline gradually. For women, this process accelerates after the age of 50, coinciding with menopause, when reduced levels of estrogen lead to a decrease in osteoblastic activity and subsequent bone matrix production.
This hormonal change increases women's risk of developing osteoporosis compared to men. Prevention of osteoporosis should start in childhood with proper nutrition, including calcium and vitamin D, alongside weight-bearing exercise to maximize bone mass and reduce future risks.