Which factor does NOT contribute to bone disease in CF patients?

In the context of cystic fibrosis (CF), several factors contribute to bone disease, but excessive exercise does not play a significant role in this context.

Malabsorption of vitamins, particularly vitamin D and K, is a key contributor to bone health issues in CF patients. The defective pancreatic function associated with CF leads to the impaired absorption of fat-soluble vitamins, resulting in deficiencies that adversely affect bone mineralization and density.

Physical inactivity is another factor that can negatively impact bone health. In children and adolescents with CF, reduced physical activity levels can lead to decreased bone strength and density, as weight-bearing exercises are crucial for healthy bone development.

Delayed puberty is also relevant, as it can impact overall growth and development, including that of the skeletal system. Delays in the onset of puberty can result in a reduction of peak bone mass, which is important for long-term orthopedic health.

Excessive exercise, while it might seem counterintuitive, is not typically associated with bone disease in CF. In fact, regular, moderate exercise is often encouraged, as it can improve overall health, increase muscle strength, and enhance bone density. Therefore, excessive exercise does not contribute to bone disease in CF patients, making it the correct choice in this particular question