To reduce your risk of avascular necrosis and improve your general health:
Limit alcohol. Heavy drinking is one of the top risk factors for developing avascular necrosis.
Keep cholesterol levels low. Tiny bits of fat are the most common substance blocking blood supply to bones.
Monitor steroid use. Make sure your doctor knows about any past or present use of high-dose steroids. Steroid-related bone damage appears to worsen with repeated courses of high-dose steroids.