Why does bone density decline with age?

Bone density declines with age primarily because the natural balance of bone remodeling shifts. While bone mass reaches its peak during young adulthood, a slow, steady loss begins around age 40 as bone resorption—the process of breaking down and assimilating old bone—begins to exceed the formation of new bone.12

Several factors contribute to this decline:

• Hormonal Changes: In women, the decline in estrogen production following menopause significantly accelerates bone loss. Similarly, testosterone deficiency in men contributes to reduced bone mass.32
• Nutritional and Physiological Factors: Decreased intake or absorption of calcium and vitamin D, often exacerbated by reduced kidney function or limited sun exposure, hinders proper bone mineralization.34
• Lifestyle and Health: Factors such as physical inactivity, smoking, excessive alcohol consumption, and certain endocrine or chronic diseases can further diminish bone density.32

Maintaining bone health is essential, as this loss of density leads to more fragile bones and an increased risk of fractures.32