title: Defining optimal vitamin D cut-off levels: Τhe role of parathyroid hormone concentrations.
authors.affiliation: First Department of Internal Medicine, Division of Endocrinology and Metabolism, AHEPA Hospital, Thessaloniki, Greece. karraspiros@yahoo.gr.
authors.forename: Spyridon N
authors.initials: SN
authors.lastname: Karras
authors.affiliation: Sunlight, Nutrition, and Health Research Center, San Francisco, CA, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Grant
authors.affiliation: School of Life Sciences, Pharmacy and Chemistry, Kingston University, Penrhyn Road, Kingston upon Thames, KT1 2EE, UK.
authors.forename: Declan P
authors.initials: DP
authors.lastname: Naughton
authors.affiliation: First Department of Internal Medicine, Division of Endocrinology and Metabolism, AHEPA Hospital, Thessaloniki, Greece.
authors.forename: Kalliopi
authors.initials: K
authors.lastname: Kotsa
mesh_terms: D006801:Humans; D010281:Parathyroid Hormone / Q000097:blood*; D012016:Reference Values; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D