Direct and indirect reference intervals of 25-hydroxyvitamin D: it is not a real vitamin D deficiency pandemic.

Autor: Perales-Afán JJ; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain.; Instituto de Investigación Sanitaria de Aragón, Zaragoza, Spain., Aparicio-Pelaz D; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain., López-Triguero S; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain., Llorente E; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain., Puente-Lanzarote JJ; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain., Fabre M; Clinical Biochemistry Department, Lozano Blesa University Hospital, Zaragoza, Spain.; Instituto de Investigación Sanitaria de Aragón, Zaragoza, Spain.
Jazyk: angličtina
Zdroj: Biochemia medica [Biochem Med (Zagreb)] 2024 Jun 15; Vol. 34 (2), pp. 020706.
DOI: 10.11613/BM.2024.020706
Abstrakt: Introduction: Many studies report vitamin D (25-OH-D) deficiency, although there is no consensus among scientific societies on cut-offs and reference intervals (RI). The aim of this study is to establish and compare RI for serum 25-OH-D by direct and indirect methods.
Materials and Methods: Two studies were performed in Zaragoza (Spain). A retrospective study (N = 7222) between January 2017 and April 2019 was used for RI calculation by indirect method and a prospective study (N = 312) with healthy volunteers recruited in August 2019 and February 2020 for direct method. Seasonal differences were investigated. Measurements were performed on Cobas C8000 (Roche-Diagnostics, Basel, Switzerland) using electrochemiluminescence immunoassay technology.
Results: Reference intervals (2.5-97.5 percentile and corresponding 95% confidence intervals, CIs) were as follows: by indirect method 5.6 ng/mL (5.4 to 5.8) - 57.2 ng/mL (55.2 to 59.8), in winter 5.4 ng/mL (5.2 to 5.7) - 55.7 ng/mL (53.6 to 58.4), while in summer 5.9 ng/mL (5.4 to 6.2) - 59.9 ng/mL (56.3 to 62.9). By direct method 9.0 ng/mL (5.7 to 9.5) - 41.4 ng/mL (37.6 to 48.0), in winter 7.4 ng/mL (3.9 to 8.6) - 34.6 ng/mL (30.6 to 51.5), while in summer 13.3 ng/mL (10.1 to 14.1) - 44.1 ng/mL (38.9 to 66.0). In both methods, RIs were higher in summer. A significant difference was observed in 25-OH-D median values between the two methods (P < 0.001).
Conclusions: Reference interval calculation according to the studied area may be a useful tool to adapt the deficiency cut-offs for 25-OH-D. Our data support 25-OH-D values over 12.0 ng/mL for healthy population as sufficient, therefore current recommendations should be updated. In addition, differences in seasonality should be taken into account.
Competing Interests: Potential conflict of interest None declared.
(Copyright Croatian Society of Medical Biochemistry and Laboratory Medicine.)
Databáze: MEDLINE
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