Fifty prepubertal male and female children of ages between 3-12 years will participate in this study. Of these, 25 obese children will be enrolled in the study group, and 25 non-obese children will serve as controls.
All subjects will fill out a comprehensive mineral intake questionnaire as part of the study to ensure adequate calcium intake prior to the study.
All subjects will collect a first morning urine sample for calcium, creatinine, and NTX.
Fasting blood samples will be drawn for the following analytes: 25-hydroxyvitamin D, 1, 25-dihydroxyvitamin D, intact PTH, calcium, phosphorus, magnesium, osteocalcin, insulin, c-peptide, fasting blood glucose, leptin, and adiponectin.
Bone Mineral Content will be evaluated in 16 obese subjects with vitamin D level of \< 30 nmol/L.