Evidence map›Paper›PMID 40579471›Full record

ArticleOsteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA2025

Vitamin B6 challenge as a tool for detecting ALPL mutations and diagnosing hypophosphatasia.

Sofía Alvarez, Amelia Ocampo, Patricia C Caso, Alvaro Del Real, Nuria Puente, Ana I Vega, Leyre Riancho-Zarrabeitia, María T García-Unzueta, José A Riancho

Abstract read
In one paragraph

Article in Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing 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

2 citing papers in PubMed.

  1. Article
  2. Interpreting Low Alkaline Phosphatase in Fibromyalgia: The Importance of Comprehensive Clinical and Biochemical Assessment.Medical principles and practice : international journal of the Kuwait University, Health Science Centre · 2026
    Article
4 · The record

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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

9 authors.

Sofía AlvarezServicio de Medicina Interna, Hospital U.M. Valdecilla, Av Valdecilla sn, 39008, Santander, Spain.
Amelia OcampoDepartamento de Medicina y Psiquiatría, Universidad de Cantabria, Santander, Spain.
Patricia C CasoDepartamento de Medicina y Psiquiatría, Universidad de Cantabria, Santander, Spain.
Alvaro Del RealServicio de Genética, Hospital U.M. Valdecilla, Santander, Spain.
Nuria PuenteServicio de Medicina Interna, Hospital U.M. Valdecilla, Av Valdecilla sn, 39008, Santander, Spain.
Ana I VegaServicio de Genética, Hospital U.M. Valdecilla, Santander, Spain.
Leyre Riancho-ZarrabeitiaDepartamento de Medicina y Psiquiatría, Universidad de Cantabria, Santander, Spain.
María T García-UnzuetaDepartamento de Medicina y Psiquiatría, Universidad de Cantabria, Santander, Spain.
José A RianchoServicio de Medicina Interna, Hospital U.M. Valdecilla, Av Valdecilla sn, 39008, Santander, Spain. rianchoj@unican.es.ORCID http://orcid.org/0000-0003-0691-8755

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Low serum alkaline phosphatase is the biochemical hallmark of hypophosphatasia. However, it is a non-specific finding. Here we show that a 2-day vitamin B6 challenge is useful to identify carriers of ALPL gene mutations among patients with low serum alkaline phosphatase, with specificity and sensitivity over 90%. PURPOSE: Hypophosphatasia (HPP) is a disorder characterized by deficient activity of the tissue non-specific alkaline phosphatase (ALP) isoenzyme, due to pathogenic variants of the ALPL gene. The biochemical hallmark of HPP is the reduced ALP activity in serum. Pyridoxal 5'-phosphate (PLP), the major circulating form of vitamin B6, is a substrate of ALP. Thus, high PLP levels are commonly used as a diagnostic marker of HPP. This study aimed to assess the diagnostic utility of vitamin B6 supplementation for identifying patients with ALPL variants. PATIENTS AND

methodsWe measured PLP in control subjects and patients with low serum ALP, with or without ALPL mutations, at baseline and after a 2-day or 6-day vitamin B6 supplementation (20 mg per day of pyridoxine hydrochloride).

resultsAlthough mutation carriers tended to have higher PLP values, up to 33% had baseline levels within the normal range. The vitamin B6 challenge, particularly with the 2-day protocol, improved the diagnostic performance. After 2-day supplementation, all carriers had levels above 500 nmol/l (sensitivity 100%; CI 95-100), whereas only 1 non-carrier surpassed that threshold (specificity 96%; CI 85-100).

conclusionA 2-day vitamin B6 supplementation test may be useful for identifying carriers of ALPL mutations among individuals with unexplained low serum ALP.

Indexed as

Alkaline PhosphataseHypophosphatasiaMutationVitamin B 6AdolescentAdultAgedBiomarkersCase-Control StudiesFemaleHumansMaleMiddle AgedPyridoxal PhosphateSensitivity and SpecificityYoung AdultAlkaline PhosphataseALPL protein, humanBiomarkersPyridoxal PhosphateVitamin B 6Alkaline phosphataseDiagnosisHypophosphatasiaPyridoxal phosphateVitamin B6

Identifiers

PMID40579471
PMCPMC12460533

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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 OpenQuestion graph.