Skeletal bone mass is determined by a combination of endogenous (genetic, hormonal) and exogenous (nutritional,
physical activity) factors. In adolescence to attain the optimal peak bone mass the main determinants are genetic, nutritional and behavioural (exercise). In adultremodeling. A number of potential candidate genes have been explored in linkage and association studies. Although earlier reports indicated that vitamin D receptor gene polymorphisms were strongly related to bone mass subsequent studies have not always confirmed these findings. Other candidate gene which are being investigated include the oestrogen receptor gene and genes for various cytokines and growth factors.