title: Understanding power calculations in clinical trials.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Prince
authors.forename: Kun
authors.initials: K
authors.lastname: Zhu
authors.forename: Joshua R
authors.initials: JR
authors.lastname: Lewis
mesh_terms: D002136:Calcium, Dietary / Q000494:pharmacology; D002986:Clinical Trials as Topic / Q000379:methods*; D005260:Female; D050723:Fractures, Bone / Q000473:pathology; D006801:Humans; D055118:Medication Adherence; D010919:Placebos; D018401:Sample Size; D014807:Vitamin D / Q000494:pharmacology
chemical_list: D002136:Calcium, Dietary; D010919:Placebos; D014807:Vitamin D