The doctors told Sarah that her mother’s bones were weakened by osteoporosis

Sarah’s mother just fell and broke her hip. The doctors told Sarah that her mother’s bones were weakened by osteoporosis. The doctor suggested that Sarah may want to have her own bone density checked, and stressed to her that she should focus on building up the bones of her 14-year-old daughter.

Why is this an important time for Sarah’s daughter to focus on building up her bone mass?

What minerals and vitamins are most important for building strong bones? Include food sources of these nutrients.