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Vitamin D Binding Protein (Gc) Allele Variation Effects Response to Vitamin D Treatment (Gc)

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ClinicalTrials.gov Identifier: NCT00650780
Recruitment Status : Completed
First Posted : April 2, 2008
Last Update Posted : April 2, 2008
Sponsor:
Information provided by:
Creighton University

Brief Summary:
We have just completed a randomized, clinical trial of 100,000 IU Vitamin D3 given as a single dose at the beginning of winter. We found a wide range of responses to the dose. This study proposes that genetic differences account for some of the variation in response of 25(OH)D levels after treatment with oral Vitamin D.

Condition or disease
Vitamin D Status

Detailed Description:

We suspect that the wide range of response is effected by other factors such as variation in Vitamin D binding protein (the major transporter of Vitamin D metabolites).

Gc, also known as Vitamin D binding protein (DBP), group specific component, or Gc globulin, is a 52-58 kDa multifunctional plasma protein, synthesized in the liver. The gene encoding for Gc is located on chromosome 4, and three common co-dominant alleles give rise to three phenotypes (Gc1s, Gc1f, and Gc2). Gc binds actin, recruits neutrophil leukocytes and converts into a macrophage- and osteoclast- activating factor. It also is the major transporter of Vitamin D and its' metabolites. Lauridsen et al. showed that Gc phenotype correlates with 25(OH)D levels in a group of postmenopausal women.

This study proposes that Gc phenotype accounts for some of the variation in response of 25(OH)D levels after treatment with oral Vitamin D.


Study Type : Observational
Actual Enrollment : 29 participants
Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Vitamin D Binding Protein (Gc) Allele Variation Effects Response to Vitamin D Treatment
Study Start Date : October 2007
Actual Primary Completion Date : January 2008
Actual Study Completion Date : January 2008

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vitamin D
Drug Information available for: Vitamin D

Group/Cohort
1
All of the subjects will have measurements of Gc concentration and phenotype



Primary Outcome Measures :
  1. Gc concentration and phenotype [ Time Frame: at 1st visit ]


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Ages Eligible for Study:   19 Years to 90 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population
This study will include thirty males and females who took part in a previous study of a single oral dose of vitamin D.
Criteria

Inclusion Criteria:

  • Must be willing to participate with an additional blood draw.
  • Must have been in the previous study.

Exclusion Criteria:

  • Will not be eligible if not a part of the previous study

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00650780


Locations
United States, Nebraska
Creighton University
Omaha, Nebraska, United States, 68131
Sponsors and Collaborators
Creighton University
Investigators
Principal Investigator: Laura Armas, MD Creighton University

Responsible Party: Laura Armas, Creighton University
ClinicalTrials.gov Identifier: NCT00650780     History of Changes
Other Study ID Numbers: Creighton4
First Posted: April 2, 2008    Key Record Dates
Last Update Posted: April 2, 2008
Last Verified: March 2008

Keywords provided by Creighton University:
Viatmin D, 25-hydroxyvitamin D, Vitamin D binding protein

Additional relevant MeSH terms:
Vitamins
Vitamin D
Ergocalciferols
Micronutrients
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents