The proposed study is a double blind cross-over placebo controlled randomized clinical study that would be conducted in the Metabolic Bone Clinic of The Children's Mercy Hospital. This is a pilot study and a more comprehensive study will be designed only if the results from this pilot study are significant. In our proposed double blind cross-over placebo controlled pilot study we will have a total of 12 children who will receive either placebo or Atorvastatin in a randomized cross-over design. The pilot study with a sample of 12 in a cross-over trial will provide reasonably stable estimates even though it is unlikely to provide statistical significance on its own but will help plan further large scale studies.