Abstract 29

Calcium intake during first three decades of life is directly associated with Peak Bone Mass (PBM) and inversely with osteoporosis fracture risk due to osteoporosis. Puberty is a critical period were the 40% of PBM and 15% of final stature is adquired and calcium requirements increase in 50%. In Chile, 64% of schoolage adolescents present calcium intake under RDA recommendations, what indicate the importance in increasing calcium nutrition in this group. We were interested in evaluate bone mineralization in low weighted girls and with low dairy products intake, to contribute with information who permit the postulation of preventive programs of osteoporosis to high risk groups. 33 scholars females with Tanner II breast stage, with 9 (n=11), 10 (n=12) and 11 (n=10) years old and low weight and dairy products intake, were studied. Bone mineral density (BMD) at spine and hip using an X-ray Lunar densitometer was evaluated, weight adequation by body mass index (BMI) and height by height/age (H/A) relation, BMD, BMI and H/A were expressed as Z score using european, national and WHO references. Nutrient and calcium intake was determined by 24 hours recordatory questionnaire using RDA recommendation. H/A was lower with elder age and statistically differences in girls between 9 and 11 age wereas observed (-0.38±0.75 and -0.90±0.43, respectively). BMI was -0.68±0.31, and no difference was observed with chronological age. Caloric intake was 76±12%, protein intake was 85±21% and calcium intake was 50±17% BMD at spine level was -1.10±0.71, and it had a tendency to decrease with age (-0.80 ± 0.64, -1.20±0.70 and -1.29±0.75 at 9, 10 and 11 years old respectively). BMD at femoral neck was normal (0.17±0.93) and a significant decrease with age was observed (0.65±0.75, 0.13±1.02 and 0.28±0.83 at 9, 10 and 11 years old, respectively). While expressing the variables H/A, BMI and BMD, according to biological age, there is a higher impairment at lower chronological age. A significative correlation (p < 0.001) between lumbar spine BMD and statural adequation was observed (r=0.500). It is concluded that schoolagers with ponderal deficit and low calcium intake, which are in an early stage of puberty present osteopenia at lumbar spine level and a significative correlation with stature was observed, while BMD femoral neck is less damaged. Possible nutritional and genetical factors influence is discussed.