<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/NCT01729013</url>
  </required_header>
  <id_info>
    <org_study_id>Tromsø-Endo-2012-2</org_study_id>
    <nct_id>NCT01729013</nct_id>
  </id_info>
  <brief_title>Duration of Vitamin D Stores After Prolonged Vitamin D Substitution</brief_title>
  <official_title>Duration of Vitamin D Stores After Prolonged Vitamin D Substitution</official_title>
  <sponsors>
    <lead_sponsor>
      <agency>University of Tromso</agency>
      <agency_class>Other</agency_class>
    </lead_sponsor>
  </sponsors>
  <source>University of Tromso</source>
  <oversight_info>
    <has_dmc>No</has_dmc>
  </oversight_info>
  <brief_summary>
    <textblock>
      Ingested or skin produced vitamin D is either hydroxylated in the liver to 25-hydroxyvitamin&#xD;
      D (25(OH)D), metabolized and excreted in the urine, or stored in adipose and other tissues.&#xD;
      The capacity for vitamin D storage in adipose tissue is not known, nor the importance of such&#xD;
      storage which may potentially be of vital importance when intake or solar exposure is&#xD;
      limited. In the present study we will include 76 subjects who have participated in an&#xD;
      intervention study with vitamin D (20.000 IU per week) versus placebo for the prevention of&#xD;
      type 2 diabetes, and who have completed the study after 5 years or who have been excluded&#xD;
      because of diagnosed type 2 diabetes or for other reasons. If vitamin D is stored to any&#xD;
      extent in the body the subjects given 20.000 IU vitamin D per week for 2-5 years will have a&#xD;
      considerable amount of stored vitamin D and accordingly, a slow decline in serum 25(OH)D&#xD;
      during the following year without vitamin D substitution, which will be measured in the&#xD;
      present study. If our hypothesis is correct, that vitamin D can be stored in significant&#xD;
      amounts when the supply is abundant; current advice on vitamin D supplementation mainly&#xD;
      during winter should be changed to &quot;year around&quot; in order to build up sufficient stores for&#xD;
      the months without sufficient sun light.&#xD;
    </textblock>
  </brief_summary>
  <overall_status>Completed</overall_status>
  <start_date>November 2012</start_date>
  <completion_date type="Actual">August 2015</completion_date>
  <primary_completion_date type="Actual">May 2015</primary_completion_date>
  <study_type>Observational</study_type>
  <has_expanded_access>No</has_expanded_access>
  <study_design_info>
    <observational_model>Cohort</observational_model>
    <time_perspective>Prospective</time_perspective>
  </study_design_info>
  <primary_outcome>
    <measure>half-life of serum 25-hydroxyvitamin D</measure>
    <time_frame>up to 12 months</time_frame>
  </primary_outcome>
  <number_of_groups>2</number_of_groups>
  <enrollment type="Actual">78</enrollment>
  <condition>Obesity</condition>
  <arm_group>
    <arm_group_label>subjects previously given placebo</arm_group_label>
  </arm_group>
  <arm_group>
    <arm_group_label>subjects previously given vitamin D</arm_group_label>
  </arm_group>
  <biospec_retention>Samples Without DNA</biospec_retention>
  <biospec_descr>
    <textblock>
      blood samples and fat biopsy&#xD;
    </textblock>
  </biospec_descr>
  <eligibility>
    <study_pop>
      <textblock>
        Subjects who have previously participated in a vitamin D study&#xD;
      </textblock>
    </study_pop>
    <sampling_method>Non-Probability Sample</sampling_method>
    <criteria>
      <textblock>
        Inclusion Criteria:&#xD;
&#xD;
          -  previously participated in a vitamin D study&#xD;
&#xD;
        Exclusion Criteria:&#xD;
&#xD;
          -  pregnancy&#xD;
      </textblock>
    </criteria>
    <gender>All</gender>
    <minimum_age>25 Years</minimum_age>
    <maximum_age>85 Years</maximum_age>
    <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
  </eligibility>
  <overall_official>
    <last_name>rolf jorde, professor</last_name>
    <role>Principal Investigator</role>
    <affiliation>University of Tromso</affiliation>
  </overall_official>
  <location>
    <facility>
      <name>University of Tromsø</name>
      <address>
        <city>Tromsø</city>
        <zip>9037</zip>
        <country>Norway</country>
      </address>
    </facility>
  </location>
  <location_countries>
    <country>Norway</country>
  </location_countries>
  <verification_date>September 2015</verification_date>
  <study_first_submitted>November 13, 2012</study_first_submitted>
  <study_first_submitted_qc>November 19, 2012</study_first_submitted_qc>
  <study_first_posted type="Estimate">November 20, 2012</study_first_posted>
  <last_update_submitted>September 18, 2015</last_update_submitted>
  <last_update_submitted_qc>September 18, 2015</last_update_submitted_qc>
  <last_update_posted type="Estimate">September 22, 2015</last_update_posted>
  <responsible_party>
    <responsible_party_type>Sponsor</responsible_party_type>
  </responsible_party>
  <keyword>vitamin D</keyword>
  <keyword>fat</keyword>
  <keyword>biopsy</keyword>
  <!-- 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/NCT01729013
org study id: Tromsø-Endo-2012-2
nct id: NCT01729013
lead sponsor: 
has dmc: No
Ingested or skin produced vitamin D is either hydroxylated in the liver to 25-hydroxyvitamin
      D (25(OH)D), metabolized and excreted in the urine, or stored in adipose and other tissues.
      The capacity for vitamin D storage in adipose tissue is not known, nor the importance of such
      storage which may potentially be of vital importance when intake or solar exposure is
      limited. In the present study we will include 76 subjects who have participated in an
      intervention study with vitamin D (20.000 IU per week) versus placebo for the prevention of
      type 2 diabetes, and who have completed the study after 5 years or who have been excluded
      because of diagnosed type 2 diabetes or for other reasons. If vitamin D is stored to any
      extent in the body the subjects given 20.000 IU vitamin D per week for 2-5 years will have a
      considerable amount of stored vitamin D and accordingly, a slow decline in serum 25(OH)D
      during the following year without vitamin D substitution, which will be measured in the
      present study. If our hypothesis is correct, that vitamin D can be stored in significant
      amounts when the supply is abundant; current advice on vitamin D supplementation mainly
      during winter should be changed to "year around" in order to build up sufficient stores for
      the months without sufficient sun light.
observational model: Cohort
time perspective: Prospective
measure: half-life of serum 25-hydroxyvitamin D
time frame: up to 12 months
arm group label: subjects previously given placebo
arm group label: subjects previously given vitamin D
blood samples and fat biopsy
study pop: 
sampling method: Non-Probability Sample
criteria: 
gender: All
minimum age: 25 Years
maximum age: 85 Years
healthy volunteers: Accepts Healthy Volunteers
last name: rolf jorde, professor
role: Principal Investigator
affiliation: University of Tromso
facility: 
country: Norway
responsible party type: Sponsor