title: How accurate are assays for 25-hydroxyvitamin D? Data from the international vitamin D external quality assessment scheme.
authors.affiliation: Endocrine Laboratory, Clinical Chemistry Department, Charing Cross Hospital, London, United Kingdom.
authors.forename: Graham D
authors.initials: GD
authors.lastname: Carter
authors.forename: Richard
authors.initials: R
authors.lastname: Carter
authors.forename: Julia
authors.initials: J
authors.lastname: Jones
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Berry
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood / Q000592:standards; D019411:Clinical Laboratory Techniques / Q000592:standards; D006801:Humans; D007391:International Cooperation; D011786:Quality Control; D012044:Regression Analysis; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood* / Q000592:standards
chemical_list: D014807:Vitamin D; D015652:25-Hydroxyvitamin D 2; C104450:25-hydroxyvitamin D