Recently, several studies in adults have revealed an inverse relationship between body fat and blood 25-hydroxyvitamin D3 [25(OH)D] levels, the relevant marker of low vitamin D status. Although vitamin D is well known for its essential role in bone metabolism and calcium homeostasis, increasing evidence is linking vitamin D to obesity. This study will evaluate vitamin D status during post operative daily supplementation of 2,000 IU of vitamin D3 and 1500 mg of calcium through assessment of changes in serum 25(OH)D, parathyroid hormone (PTH), calcium and phosphorus at baseline, 4 weeks, and 12 weeks following surgery. The dietary contribution of vitamin D and calcium will be estimated by food records analyzed using the University of Minnesota 2010 Nutrition Data System for Research (NDSR) program.