Study subjects will be obese children between the ages of 2 and 11 years who are being seen at the FIT (Families Improving Health Together) program. As part of their routine care, all patients seen at the FIT program will have weight measured to the nearest 0.1 kilogram by digital floor scale, stature by wall-mounted stadiometer and waist circumference measurements to the nearest 0.1 centimeter. BMI will be calculated as weight in kilograms, divided by height in meters squared (kg/m2). Waist circumference will be measured with a tape measure at the uppermost lateral border of the hip crest (ilium). Percentage body fat will be approximated by bioelectrical impedance analysis. All patients will have 25-hydroxyvitamin D measured, which will be sent to Esoterix Labs (Calabasas Hills, CA) and run by high-pressure liquid chromatography/tandem mass spectrometry (HPLC/MS-MS). Other baseline labs that will be drawn include glucose, insulin, hemoglobin A1c, lipid panel, hepatic function panel and basic metabolic panel. Blood from the initial visit will be banked for future research laboratory testing as part of the overall goal of the FIT program. The research labs that will be run include vitamin D binding protein, osteocalcin, c-telopeptide, P1NP, PTH, IL-6 and TNF-alpha.