ABSTRACT
Bone mass is the result of a constant balance between breakdown and formation under the control of several factors that can be grouped into two categories:
1. Genetics, ethnicity, gender, age, and body (frame) size that cannot be modified
2. Hormonal status (especially sex and calcitropic hormone status), lifestyle factors (including diet), physical activity and levels, and smoking and alcohol consumption patterns that can be modulated or changed
The interaction of these factors influences both the development of bone during childhood and adolescence until it reaches its peak mass at maturity and its subsequent slow loss later in life. Genetic factors probably account for up to 80% of the bone mass variation in the population.
