Bone size and bone mass in 10-year-old Danish children: effect of current diet

Lifestyle factors, such as diet, are believed to be involved in modifying bone health, although the results remain controversial, particularly in children and adolescents. The objective of the study was to identify associations between dietary factors and whole body bone measurements in 10-year-old children. The study was a cross-sectional analysis of a random sample of 105 healthy Danish children, aged 10 years (9.97+/-0.09). Whole body bone mineral content (BMC) and bone area (BA) were determined by dual-energy X-ray absorptiometry. The influence of diet (7 day food records) on BMC and BA were examined in bi- and multivariate analyses. The mean intakes of calcium, protein, phosphorus and sodium were 1226 mg, 78 g, 1523 mg and 3.3 g, respectively. In bivariate analyses, BMC and BA were strongly positively correlated with height (p<0.001) and weight (p<0.001), and with intakes of energy (p<0.005) and several nutrients. BMC was adjusted for size by including BA, height and weight in the multiple linear regression, and BA was adjusted for size by including height and weight in the multiple linear regression. In multivariate analyses, size-adjusted BMC was positively associated with calcium intake (p=0.02). Size-adjusted BA was positively associated with dietary protein (p=0.003), and negatively associated with intakes of sodium (p = 0.048) and phosphorus (p=0.01). In conclusion, calcium intake was positively associated with bone mineralization. There was a positive association between protein and BA, while for phosphorus and sodium the association was negative.