<clinical_study>
  <!-- This xml conforms to an XML Schema at:
    https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
  <required_header>
    <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
    <link_text>Link to the current ClinicalTrials.gov record.</link_text>
    <url>https://clinicaltrials.gov/ct2/show/NCT03304795</url>
  </required_header>
  <id_info>
    <org_study_id>NRF-2015R1C1A1A01054333</org_study_id>
    <nct_id>NCT03304795</nct_id>
  </id_info>
  <brief_title>Vitamin D Deficiency Still Growing</brief_title>
  <official_title>Is Vitamin D Deficiency Still Growing? Seven-Year Trend in KNHANES 2008-2014</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>DongGuk University</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>DongGuk University</source>
  <oversight_info>
    <has_dmc>Yes</has_dmc>
    <is_fda_regulated_drug>No</is_fda_regulated_drug>
    <is_fda_regulated_device>No</is_fda_regulated_device>
  </oversight_info>
  <brief_summary>
    <textblock>
      Vitamin D deficiency has become one of the most prevalent health problems in modern society.&#xD;
      However, there has been no study that has reported the trend of vitamin D status in Asia.&#xD;
      This study investigated the trend of vitamin D status in Korea between 2008 and 2014.&#xD;
&#xD;
      This study is based on a representative national database acquired from the Korea National&#xD;
      Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2014. Serum&#xD;
      25-hydroxyvitamin D [25(OH)D] levels were measured by radioimmunoassay among those aged 10&#xD;
      yrs or older. The temporal change of vitamin D status will be statistically analyzed.&#xD;
    </textblock>
  </brief_summary>
  <detailed_description>
    <textblock>
      Most epidemiologic studies that assessed vitamin D status in various populations have been&#xD;
      performed in a cross-sectional design. Some studies from western countries have assessed the&#xD;
      trends of vitamin D status over the past decades. However, there was no study that&#xD;
      investigated the trend of vitamin D status in Asian population.&#xD;
&#xD;
      In the present study, an assessment of the seven-year trend of vitamin D status and the&#xD;
      prevalence of vitamin D deficiency in the Korean population, based on the KNHANES conducted&#xD;
      from 2008 to 2014 was performed.&#xD;
&#xD;
      The KNHANES is an ongoing surveillance system that has been conducted by the Division of&#xD;
      Health and Nutrition Survey within the Korea Centers for Disease Control and Prevention to&#xD;
      evaluate the health and nutritional status of the civilian non-institutionalized population&#xD;
      of South Korea. Since the KNHANES was initiated in 1998, surveys for the KNHANES I (1998),&#xD;
      KNHANES II (2001), KNHANES III (2005), KNHANES IV (2007-2009), KNHANES V (2010-2012), and&#xD;
      KNHANES VI (2013-2015) have been executed, and the survey for KNHANES VII (2016-2018) is&#xD;
      still in progress. The present study is based on the data acquired from the KNHANES IV-VI,&#xD;
      conducted between 2008 and 2014. Among those participants, serum 25(OH)D levels were measured&#xD;
      from 39,759 individuals (6,925 in 2008; 8,303 in 2009; 6,815 in 2010; 6,704 in 2011; 6,308 in&#xD;
      2012; 2,355 in 2013; and 2,349 in 2014) aged 10 years and older. Serum 25(OH)D concentration&#xD;
      was categorized into 4 levels (&lt;25, 25 to &lt;50, 50 to &lt;75, and ≥75 nmol/L) and the vitamin D&#xD;
      deficiency was defined as the Serum 25 (OH) D concentration &lt; 50 nmol/L.&#xD;
&#xD;
      Statistical analyses were conducted to evaluate the effects of participant characteristics&#xD;
      (age, season, and residential region) on serum 25(OH)D concentrations, and the temporal&#xD;
      change in the mean concentration of serum 25(OH)D over years 2008-2014.&#xD;
    </textblock>
  </detailed_description>
  <overall_status>Completed</overall_status>
  <start_date type="Actual">January 1, 2008</start_date>
  <completion_date type="Actual">December 31, 2014</completion_date>
  <primary_completion_date type="Actual">December 31, 2014</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Ecologic or Community</observational_model>
    <time_perspective>Cross-Sectional</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>Vitamin D deficiency</measure>
    <time_frame>2008-2014</time_frame>
    <description>Serum 25-hydroxyvitamin D level less than 50 nmol/L</description>
  </primary_outcome>
  <number_of_groups>2</number_of_groups>
  <enrollment type="Actual">39759</enrollment>
  <condition>Vitamin D Deficiency</condition>
  <arm_group>
    <arm_group_label>Vitamin D deficiency</arm_group_label>
    <description>Serum 25-hydroxyvitamin D level is less than 50 nmol/L.</description>
  </arm_group>
  <arm_group>
    <arm_group_label>Normal</arm_group_label>
    <description>Serum 25-hydroxyvitamin D level is 50 nmol/L or greater.</description>
  </arm_group>
  <eligibility>
    <study_pop>
      <textblock>
        The KNHANES is an ongoing surveillance system to evaluate the health and nutritional status&#xD;
        of the civilian non-institutionalized population of South Korea. The present study&#xD;
        population is from the KNHANES 2008-2014. Among the participants in KNHANES 2008-2014,&#xD;
        those aged 10 years and older with serum 25(OH)D levels were finally included (n=39,759).&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  Participants in the KNHANES from 2008 to 2014&#xD;
&#xD;
          -  Participants who were examined for serum 25-hydroxyvitamin D level&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  Participants without serum 25-hydroxyvitamin D level data&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>10 Years</minimum_age>
    <maximum_age>N/A</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <verification_date>October 2017</verification_date>
  <study_first_submitted>October 4, 2017</study_first_submitted>
  <study_first_submitted_qc>October 6, 2017</study_first_submitted_qc>
  <study_first_posted type="Actual">October 9, 2017</study_first_posted>
  <last_update_submitted>October 6, 2017</last_update_submitted>
  <last_update_submitted_qc>October 6, 2017</last_update_submitted_qc>
  <last_update_posted type="Actual">October 9, 2017</last_update_posted>
  <responsible_party>
    <responsible_party_type>Principal Investigator</responsible_party_type>
    <investigator_affiliation>DongGuk University</investigator_affiliation>
    <investigator_full_name>Han Seok Choi</investigator_full_name>
    <investigator_title>Associate Professor</investigator_title>
  </responsible_party>
  <keyword>Vitamin D</keyword>
  <keyword>Asia</keyword>
  <keyword>Trend</keyword>
  <keyword>KNHANES</keyword>
  <keyword>Temporal change</keyword>
  <condition_browse>
    <!-- CAUTION:  The following MeSH terms are assigned with an imperfect algorithm            -->
    <mesh_term>Vitamin D Deficiency</mesh_term>
  </condition_browse>
  <patient_data>
    <sharing_ipd>No</sharing_ipd>
  </patient_data>
  <!-- Results have not yet been posted for this study                                          -->
</clinical_study>


download date: ClinicalTrials.gov processed this data on September 20, 2023
link text: Link to the current ClinicalTrials.gov record.
url: https://clinicaltrials.gov/ct2/show/NCT03304795
org study id: NRF-2015R1C1A1A01054333
nct id: NCT03304795
lead sponsor: 
has dmc: Yes
is fda regulated drug: No
is fda regulated device: No
Vitamin D deficiency has become one of the most prevalent health problems in modern society.
      However, there has been no study that has reported the trend of vitamin D status in Asia.
      This study investigated the trend of vitamin D status in Korea between 2008 and 2014.

      This study is based on a representative national database acquired from the Korea National
      Health and Nutrition Examination Surveys (KNHANES) conducted from 2008 to 2014. Serum
      25-hydroxyvitamin D [25(OH)D] levels were measured by radioimmunoassay among those aged 10
      yrs or older. The temporal change of vitamin D status will be statistically analyzed.
Most epidemiologic studies that assessed vitamin D status in various populations have been
      performed in a cross-sectional design. Some studies from western countries have assessed the
      trends of vitamin D status over the past decades. However, there was no study that
      investigated the trend of vitamin D status in Asian population.

      In the present study, an assessment of the seven-year trend of vitamin D status and the
      prevalence of vitamin D deficiency in the Korean population, based on the KNHANES conducted
      from 2008 to 2014 was performed.

      The KNHANES is an ongoing surveillance system that has been conducted by the Division of
      Health and Nutrition Survey within the Korea Centers for Disease Control and Prevention to
      evaluate the health and nutritional status of the civilian non-institutionalized population
      of South Korea. Since the KNHANES was initiated in 1998, surveys for the KNHANES I (1998),
      KNHANES II (2001), KNHANES III (2005), KNHANES IV (2007-2009), KNHANES V (2010-2012), and
      KNHANES VI (2013-2015) have been executed, and the survey for KNHANES VII (2016-2018) is
      still in progress. The present study is based on the data acquired from the KNHANES IV-VI,
      conducted between 2008 and 2014. Among those participants, serum 25(OH)D levels were measured
      from 39,759 individuals (6,925 in 2008; 8,303 in 2009; 6,815 in 2010; 6,704 in 2011; 6,308 in
      2012; 2,355 in 2013; and 2,349 in 2014) aged 10 years and older. Serum 25(OH)D concentration
      was categorized into 4 levels (<25, 25 to <50, 50 to <75, and ≥75 nmol/L) and the vitamin D
      deficiency was defined as the Serum 25 (OH) D concentration < 50 nmol/L.

      Statistical analyses were conducted to evaluate the effects of participant characteristics
      (age, season, and residential region) on serum 25(OH)D concentrations, and the temporal
      change in the mean concentration of serum 25(OH)D over years 2008-2014.
observational model: Ecologic or Community
time perspective: Cross-Sectional
measure: Vitamin D deficiency
time frame: 2008-2014
description: Serum 25-hydroxyvitamin D level less than 50 nmol/L
arm group label: Vitamin D deficiency
description: Serum 25-hydroxyvitamin D level is less than 50 nmol/L.
arm group label: Normal
description: Serum 25-hydroxyvitamin D level is 50 nmol/L or greater.
study pop: 
sampling method: Probability Sample
criteria: 
gender: All
minimum age: 10 Years
maximum age: N/A
healthy volunteers: Accepts Healthy Volunteers
responsible party type: Principal Investigator
investigator affiliation: DongGuk University
investigator full name: Han Seok Choi
investigator title: Associate Professor
mesh term: Vitamin D Deficiency
sharing ipd: No