title: Letter of concern regarding a possible shortage of separated isotopes.
authors.forename: S A
authors.initials: SA
authors.lastname: Abrams
authors.forename: P D
authors.initials: PD
authors.lastname: Klein
authors.forename: V R
authors.initials: VR
authors.lastname: Young
authors.forename: D M
authors.initials: DM
authors.lastname: Bier
mesh_terms: D002127:Calcium Isotopes; D002648:Child; D005260:Female; D006801:Humans; D009747:Nutritional Physiological Phenomena; D010103:Oxygen Isotopes; D011247:Pregnancy; D012107:Research Design
chemical_list: D002127:Calcium Isotopes; D010103:Oxygen Isotopes