The authors report that in 33 patients who underwent stretching of the extremity by the method of dosed distraction after G. A. Ilizarov following corticotomy there were no significant changes in a number of biochemical values (serum concentrations of general protein, albumin, urea, uric acid, glucose, cholesterol, triglycerides, magnesium, chlorides). The level of other values (alkaline phosphatase and lactate dehydrogenase enzymes, etc.) increased and sometimes exceeded the physiological limits of its age group, but did not exceed the normal limits in the population as a whole. A reliable change in the values was observed with their level being higher during the period of natural growth because of intensification of anabolic processes and growth of the mass of organs and tissues or increase in their function. A rise in serum concentrations of calcium, phosphate and hydroxyproline with the urine demonstrates in combination with the data of biphoton densimetry of the skeleton and distraction regenerate that at the same time with improved absorption of electrolytes in the intestines during distraction there was an activation of mobilization of the minerals from the intact skeleton. A problem of adequate consumption of mineral substances with the food is put forward.