Evidence map›Paper›PMID 42440151›Full record

ArticleEndocrine2026

Interlaboratory method-dependent variability may impact reimbursement policies based on a priori determined 25-hydroxyvitamin D threshold levels.

Luigi di Filippo, Eleonora Sabetta, Simona Bolamperti, Fabrizio Nannipieri, Massimo Locatelli, Andrea Giustina

Abstract read
PubMed Publisher
In one paragraph

Article in Endocrine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Luigi di FilippoInstitute of Endocrine and Metabolic Sciences, Università Vita-Salute San Raffaele and IRCCS Ospedale San Raffaele, Milan, Italy.
Eleonora SabettaLaboratory Medicine Service, IRCCS Ospedale San Raffaele, Milan, Italy.
Simona BolampertiInstitute of Endocrine and Metabolic Sciences, Università Vita-Salute San Raffaele and IRCCS Ospedale San Raffaele, Milan, Italy.
Fabrizio NannipieriInstitute of Endocrine and Metabolic Sciences, Università Vita-Salute San Raffaele and IRCCS Ospedale San Raffaele, Milan, Italy.
Massimo LocatelliLaboratory Medicine Service, IRCCS Ospedale San Raffaele, Milan, Italy.
Andrea GiustinaInstitute of Endocrine and Metabolic Sciences, Università Vita-Salute San Raffaele and IRCCS Ospedale San Raffaele, Milan, Italy. giustina.andrea@hsr.it.ORCID 0000-0001-6783-3398

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

introductionVitamin D supplementation is widely used in clinical practice and its administration is based on circulating 25-hydroxyvitamin D [25(OH)D] concentrations. However, 25(OH)D is an analytically challenging biomarker, and the influence of interlaboratory method-dependent variability on the routine applicability of fixed biochemical cut-offs as the only criterion for reimbursements of vitamin D supplementation remains insufficiently defined. We aimed to quantify interlaboratory analytical variability in 25(OH)D measurements using External-Quality-Assessment (EQA) data from the Lombardy region healthcare system.

methodsRetrospective analysis was performed on External Quality Controls data collected through EQA program run by Lombardy Regional Coordination Center for Laboratory Medicine during 2024-2025. Cross-laboratory control assessment utilized statistical measures including mean, coefficients of variation (CVs%), and platform-to-platform analytical comparisons.

resultsOver a two-year period, a total of 2,747 individual 25(OH)D results from approximately 114 laboratories per EQA-round were analyzed. Mean reported 25(OH)D concentration was 28.68 (SD:11.28) ng/mL, with values ranging from 16.94 to 72.57 ng/mL. Across all analytical platforms evaluated, substantial dispersion of results was observed (p < 0.001). Interlaboratory variability was substantial, with CVs ranging from 18.10 to 45.35% and a mean of 29.98% (5.96). Notably, analytical variability remained consistently high across clinically used cut-offs (< 30 and ≥ 30 ng/mL), with similar mean CVs (29.98% (5.85) vs. 29.97% (6.58), respectively; p = 0.996).

conclusionsIn real-world healthcare settings, interlaboratory analytical variability of 25(OH)D EQA measurements is high and independent of clinically adopted thresholds. These findings suggest that approaches to vitamin D administration and reimbursement based on the general application of a priori determined rigid 25(OH)D threshold levels might result methodologically fragile, supporting a greater role for clinical judgment in decisions regarding vitamin D supplementation.

Indexed as

Vitamin DDietary SupplementsHumansQuality ControlReproducibility of ResultsRetrospective Studies25-hydroxyvitamin DVitamin D25(OH)D measurementsExternal quality assessmentLaboratoryVitamin DVitamin D supplementation

Identifiers

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.