BACKGROUND. We expect significant relations from D vitamin receptor (VDR) gene polymorphism and BMD analysis corrected according to bone age (BA), which could explain substantiation of biological factors determination at young sportsmen's training. METHODS. We examined genotype frequencies and allele incidence of VDR FokI and BsmI polymorphisms in 99 young athletes (48 boys aged 13.9 +/- 1.467 and 51 girls aged 13.4 +/- 1.139). BMD at the left hip (LH) and lumbar spine (LS) was identified by dual x-ray absorptiometry and skeletal maturity according TW3 method. RESULTS. We identified 51.5% children with genotype CC, 38.4% CT heterozygotes and TT homozygotes 10.1% of FokI gene polymorphism. Significant BMD difference was found between CC and CT (P<0.01). BMD was associated with gene BsmI (AA and AG, P<0.01, AG and GG, P<0.01). Distribution of BsmI genotypes was as follows 15.1% AA, 51.5% AG and 33.3% GG. CONCLUSIONS. Therefore it is undisputed that the results of biological-medicine examination of the youth in ontogenesis should be evaluated upon correction according to the bone age since it affects objectivity of final assessment of children and youth.