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
  Purpose

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


Condition
Vitamin D Deficiency

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Cross-Sectional
Official Title: Environmental & Genetic Influences on Vitamin D Status

Resource links provided by NLM:


Further study details as provided by Creighton University:

Primary Outcome Measures:
  • 25(OH)D levels [ Time Frame: 1 month ] [ Designated as safety issue: No ]
    25(OH)D levels were measured at the only visit


Secondary Outcome Measures:
  • 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.


Biospecimen Retention:   Samples With DNA

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


Enrollment: 40
Study Start Date: August 2010
Study Completion Date: August 2010
Primary Completion Date: August 2010 (Final data collection date for primary outcome measure)
Groups/Cohorts
Sun exposed people
Sun exposure >3 hours daily for at least 5 days weekly for the last 3 months.

Detailed Description:

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.

  Eligibility

Ages Eligible for Study:   18 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Non-Probability Sample
Study Population

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

The subjects will be between ages 18-60.

Criteria

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.
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01208636

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

No publications provided

Responsible Party: Laura Armas, Creighton University
ClinicalTrials.gov Identifier: NCT01208636     History of Changes
Other Study ID Numbers: Creighton9
Study First Received: August 30, 2010
Last Updated: September 23, 2010
Health Authority: United States: Institutional Review Board

Keywords provided by Creighton University:
Vitamin D deficiency
Sun
Genetics

Additional relevant MeSH terms:
Vitamin D Deficiency
Avitaminosis
Deficiency Diseases
Malnutrition
Nutrition Disorders
Vitamin D
Ergocalciferols
Vitamins
Bone Density Conservation Agents
Physiological Effects of Drugs
Pharmacologic Actions
Micronutrients
Growth Substances

ClinicalTrials.gov processed this record on July 24, 2014