Consumption of Very Low Mineral Water Is Associated with Lower Bone Mineral Content in Children.

Background: Our previous study found that consumption of very low mineral drinking water may retard height development in schoolchildren; however, its association with bone modeling remained unknown. Objectives: The aim of this study was to investigate the influence of very low mineral water on biomarkers of bone modeling in children. Methods: A retrospective cohort study was conducted among 2 groups of 10-13-y-old children who had consumed drinking water with normal mineral contents (conductivity 345 mu s/cm, the NW group including 119 boys and 110 girls) or very low mineral contents (conductivity 40.0 mu s/cm, the VLW group including 223 boys and 208 girls) in school for 4 y. Differences in daily total mineral intakes, developmental parameters, serum biomarkers of osteoblast activity, and bone formation and resorption between the 2 groups were analyzed with independent t test and chi-square test. Associations of developmental parameters and serum biomarkers with Ca intake from drinking water were analyzed with multiple linear regression and binary logistic regression. Results: Compared with the NW group, the VLW group had lower daily Ca intake, height increase, bone mineral content (BMC), osteoblast activity [serum bone alkaline phosphatase (BALP)] (means +/- SDs: 433 +/- 131 mg, 16.6 +/- 8.27 cm, 1.92 +/- 0.431 kg, and 9.28 +/- 1.42 mu g/L compared with 497 +/- 155 mg, 22.3 +/- 8.45 cm, 2.14 +/- 0.354 kg, and 11.0 +/- 0.823 mu g/L, respectively, P < 0.001), and higher bone resorption [serum crosslinked C-telopeptide of type I collagen (CTX), mean +/- SD: 142 +/- 46.9 nmol/L compared with 130 +/- 40.6 nmol/L, P = 0.001). Ca intake from drinking water was positively associated with height increase, BMC, and BALP (beta: 0.0667, 95% CI: 0.0540, 0.0793; beta: 3.22, 95% CI: 2.37, 4.08; and beta: 23.9, 95% CI: 20.6, 27.2), respectively, P < 0.001), and was negatively associated with CTX (beta:-0.206, 95% CI:-0.321,-0.0904, P < 0.001) Conclusions: These changes suggested that consumption of very low mineral water may be associated with osteoblast inhibition, bone resorption activation, bone mineral reduction, and height development retardation. The health risk of consuming very low mineral water should be considered in children.