Vitamin D; Parathyroid Hormone; Humans; Adult; Middle Aged; Vitamin D Deficiency; Medicine (all); Biochemistry (medical); Clinical Biochemistry
Abstract :
[en] [en] BACKGROUND: Determining serum 25-hydroxyvitamin D [25(OH)D], 24,25-dihydroxyvitamin D [24,25(OH)2D] and the vitamin D metabolite ratio (VMR) allows the identification of individuals with a low vitamin D metabolite profile. Here, we evaluated if such a functional approach provides superior diagnostic information to serum 25(OH)D alone.
METHODS: 25(OH)D, 24,25(OH)2D, and the VMR were determined in participants of the DESIRE (Desirable Vitamin D Concentrations, n = 2010) and the LURIC (Ludwigshafen Risk and Cardiovascular Health, n = 2456) studies. A low vitamin D metabolite profile (vitamin D insufficiency) was defined by a 24,25(OH)2D concentration <1.2 ng/mL (<3 nmol/L) and a VMR <4%. Parathyroid hormone (PTH) and bone turnover markers were measured in both cohorts, whereas 10-year mortality data was recorded in LURIC only.
RESULTS: The median age in DESIRE and LURIC was 43.3 and 63.8 years, respectively. Median 25(OH)D concentrations were 27.2 ng/mL (68.0 nmol/L) and 15.5 ng/mL (38.8 nmol/L), respectively. Serum 25(OH)D deficiency, defined as <20.2 ng/mL (<50 nmol/L), was present in 483 (24.0%) and 1701 (69.3%) participants of DESIRE and LURIC, respectively. In contrast, only 77 (3.8%) and 521 (21.2%) participants had a low vitamin D metabolite profile. Regardless of the serum 25(OH)D concentration, a low vitamin D metabolite profile was associated with a significantly higher PTH, accelerated bone metabolism, and higher all-cause mortality than an unremarkable vitamin D metabolite profile.
CONCLUSIONS: The personalized assessment of vitamin D status using a functional approach better identifies patients with accelerated bone metabolism and increased mortality than the use of a fixed 25(OH)D cutoff of 20 ng/mL (50 nmol/L).
Disciplines :
Laboratory medicine & medical technology
Author, co-author :
Herrmann, Markus ; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Zelzer, Sieglinde; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Cavalier, Etienne ; Centre Hospitalier Universitaire de Liège - CHU > > Service de chimie clinique
Kleber, Marcus; Department of Internal Medicine 5 (Nephrology, Hypertensiology, Endocrinology, Diabetology, Rheumatology), Mannheim Medical Faculty, University of Heidelberg, Mannheim, Germany ; Synlab Human Genetics Laboratory, Synlab AG, Mannheim, Germany
Drexler-Helmberg, Camilla; Department for Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria
Schlenke, Peter; Department for Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria
Curcic, Pero; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Keppel, Martin H; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Enko, Dietmar; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Scharnagl, Hubert ; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria
Pilz, Stefan ; Division of Endocrinology and Diabetology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
März, Winfried; Clinical Institute of Medical and Chemical Laboratory Diagnostics, Medical University of Graz, Graz, Austria ; Synlab Human Genetics Laboratory, Synlab AG, Mannheim, Germany ; Synlab Academy, Synlab Holding Germany GmbH, Mannheim, Germany
Language :
English
Title :
Functional Assessment of Vitamin D Status by a Novel Metabolic Approach: The Low Vitamin D Profile Concept.
