Compare these two patients: Patient A is a 70-year-old active man with adequate calcium/vitamin D intake; Patient B is a 55-year-old postmenopausal woman who is sedentary and has low dietary calcium. Which patient is at higher lifetime risk for fragility fractures and why?

• A. Patient B, because postmenopausal estrogen deficiency combined with sedentary behavior and low calcium intake accelerates trabecular bone loss and increases fracture risk more than aging alone in a man with adequate nutrition and regular activity.
• B. Both have equal risk because age is the only determinant of osteoporosis and lifestyle or sex differences are secondary and do not materially affect fracture probability.
• C. Patient A, because men accumulate more bone loss after age 65 and activity increases turnover leading to higher risk of microfractures despite good nutrition.
• D. Patient B if and only if she also has a documented vitamin C deficiency; calcium and estrogen status alone are insufficient to change fracture risk substantially without concurrent collagen impairments.

Answer: (A)