Normal bone mass is one of the principal factors in the prevention of osteoporosis for women in advanced age. Therefore, it is necessary to have efficacious serum and urinary markers available to screen the bone development and the bone resorption. Even if we are also far from identifying an ideal marker, the measurement of some substances such as pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) seems to be a first progress for efficacious and rather simple techniques.