Environmental & Genetic Influences on Vitamin D Status

This study has been completed.
Sponsor:
Collaborator:
Procter and Gamble
Information provided by:
Creighton University
ClinicalTrials.gov Identifier:
NCT01208636
First received: August 30, 2010
Last updated: September 23, 2010
Last verified: September 2010

August 30, 2010
September 23, 2010
August 2010
August 2010   (final data collection date for primary outcome measure)
25(OH)D levels [ Time Frame: 1 month ] [ Designated as safety issue: No ]
25(OH)D levels were measured at the only visit
Same as current
Complete list of historical versions of study NCT01208636 on ClinicalTrials.gov Archive Site
Genetic testing of 13 candidate genes [ Time Frame: 1 month ] [ Designated as safety issue: No ]
13 candidate genes were tested and their relationship to 25(OH)D examined.
Same as current
Not Provided
Not Provided
 
Environmental & Genetic Influences on Vitamin D Status
Environmental & Genetic Influences on Vitamin D Status

The purpose of this study is to determine the effect of environmental and genetic influences on Vitamin D status.

Vitamin D deficiency is a common problem. The principal source of vitamin D for humans is solar exposure, with cutaneous synthesis of vitamin D by photoconversion of 7-dehydrocholesterol in the skin to pre-vitamin D3. Latitude, altitude, season, skin pigmentation, and age are recognized factors that influence how much vitamin D can be made by solar exposure. Surprisingly, Vitamin D deficiency has been described in people dwelling in southern Florida and in surfers in Hawaii. We hypothesize that genetic variations in vitamin metabolism accounts for these differences.

Observational
Observational Model: Cohort
Time Perspective: Cross-Sectional
Not Provided
Retention:   Samples With DNA
Description:

Blood was obtained for genetic testing of selected 13 candidate genes important for vitamin D metabolism

Non-Probability Sample

This study will include 50 "healthy" unrelated community dwelling males or females.

The subjects will be between ages 18-60.

Vitamin D Deficiency
Not Provided
Sun exposed people
Sun exposure >3 hours daily for at least 5 days weekly for the last 3 months.
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
40
August 2010
August 2010   (final data collection date for primary outcome measure)

Inclusion Criteria:

  • Able to consent and come for a study visit.
  • Male or female between ages 18-60.
  • Sun exposure >3 hours daily for at least 5 days weekly for the last 3 months.

Exclusion Criteria:

  • Unable to consent or come to a visit
  • Taking Vitamin D supplements, anticonvulsants, barbiturates, steroids, having granulomatous disease, or liver or kidney disease as these medications and conditions interfere with Vitamin D metabolism.
  • Related to another participant by blood.
Both
18 Years to 60 Years
Yes
Contact information is only displayed when the study is recruiting subjects
United States
 
NCT01208636
Creighton9
No
Laura Armas, Creighton University
Creighton University
Procter and Gamble
Principal Investigator: Laura Armas, MD Creighton University
Creighton University
September 2010

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP