<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1889-836X</journal-id>
<journal-title><![CDATA[Revista de Osteoporosis y Metabolismo Mineral]]></journal-title>
<abbrev-journal-title><![CDATA[Rev Osteoporos Metab Miner]]></abbrev-journal-title>
<issn>1889-836X</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Española de Investigaciones Óseas y Metabolismo Mineral]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1889-836X2019000100006</article-id>
<article-id pub-id-type="doi">10.4321/s1889-836x2019000100006</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Vitamina D libre: una determinación en aumento]]></article-title>
<article-title xml:lang="en"><![CDATA[Free vitamin D: an increasing determination]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Quesada Gómez]]></surname>
<given-names><![CDATA[M]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Heureux]]></surname>
<given-names><![CDATA[N]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Hospital Universitario Reina Sofía Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC) Unidad de Gestión Clínica de Endocrinología y Nutrición - Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES)]]></institution>
<addr-line><![CDATA[Córdoba ]]></addr-line>
<country>España</country>
</aff>
<aff id="A02">
<institution><![CDATA[,DIAsource ImmunoAssays  ]]></institution>
<addr-line><![CDATA[Louvain-la-Neuve ]]></addr-line>
<country>Bélgica</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>03</month>
<year>2019</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>03</month>
<year>2019</year>
</pub-date>
<volume>11</volume>
<numero>1</numero>
<fpage>30</fpage>
<lpage>34</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_arttext&amp;pid=S1889-836X2019000100006&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_abstract&amp;pid=S1889-836X2019000100006&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://scielo.isciii.es/scielo.php?script=sci_pdf&amp;pid=S1889-836X2019000100006&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen La vitamina D es un concepto familiar para cualquier profesional que trabaje en biología clínica, pero ahora lo es también para una gran parte de la población. Los colosales esfuerzos de investigación desarrollados durante la última década han conducido a una explosión del número de determinaciones solicitadas del metabolito más cualificado para expresar el estado corporal de la vitamina D, 25-OH vitamina D (25-OHD) libre, representa la pequeña fracción no ligada a las proteínas transportadoras. De acuerdo con la hipótesis de la hormona libre, debería ser considerada como la mejor representación del estado corporal de la vitamina D. Lamentablemente, se ha prestado poca atención a esta determinación ya que, hasta hace poco, la comunidad científica solo disponía de métodos indirectos y tediosos para medirla. Hace unos pocos años que se publicó un método de medición directa del 25-OHD libre ya disponible para efectuar estudios de investigación con resultados prometedores.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Summary Vitamin D has long been a familiar concept for any professional working in clinical biology. Nowadays it is becoming known to a large sector of the population. The great research efforts developed over the past decade have led to an explosion in the number of determinations requested of the most qualified metabolite to express the body state of vitamin D, 25-OH vitamin D (25-OHD) free, represents the small fraction not bound to transporter proteins. According to the free hormone hypothesis, it should be considered the best representation of the body state of vitamin D. Unfortunately, limited attention has been paid to this determination since, until recently, the scientific community only had tedious, indirect methods to measure it. A few years ago, a direct measurement method of free 25-OHD was already available to carry out research studies with promising results.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[cáncer colorrectal]]></kwd>
<kwd lng="es"><![CDATA[envejecimiento]]></kwd>
<kwd lng="es"><![CDATA[osteoporosis]]></kwd>
<kwd lng="es"><![CDATA[gestación]]></kwd>
<kwd lng="es"><![CDATA[infertilidad]]></kwd>
<kwd lng="es"><![CDATA[25-hidroxivitamina D]]></kwd>
<kwd lng="es"><![CDATA[25 hidroxivitamina D libre]]></kwd>
<kwd lng="es"><![CDATA[1,25-dihidroxivitamina D]]></kwd>
<kwd lng="en"><![CDATA[colorectal cancer]]></kwd>
<kwd lng="en"><![CDATA[aging]]></kwd>
<kwd lng="en"><![CDATA[osteoporosis]]></kwd>
<kwd lng="en"><![CDATA[pregnancy]]></kwd>
<kwd lng="en"><![CDATA[infertility]]></kwd>
<kwd lng="en"><![CDATA[25-hydroxyvitamin D]]></kwd>
<kwd lng="en"><![CDATA[25 hydroxyvitamin D free]]></kwd>
<kwd lng="en"><![CDATA[1,25-dihydroxyvitamin D]]></kwd>
</kwd-group>
</article-meta>
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