The degree of mineralization in normal bone tissue estimated as the phosphorus to hydroxyproline ratio.

The degree of mineralization can be evaluated from the phosphorus to hydroxyproline ratio in bone biopsies. A small but significant rise in the ratio with increasing age was observed in 137 persons without bone diseases, aged from 20 to 89 years. No significant difference between men and women was found with regard to the phosphorus to hydroxyproline ratio. The study indicates that with increasing age, in addition to senile osteopenia, there is also a change in the form of an increase in the degree of mineralization.