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Sunlight Exposures Effect on Serum Vitamin D Levels

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00473317
First Posted: May 15, 2007
Last Update Posted: April 1, 2008
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by:
Creighton University
  Purpose
When people eat a meal, some, but not all of the calcium in that meal is absorbed, that is, moved into the bloodstream. When the skin is exposed to sunlight during summer months, Vitamin D is made there and then modified into more active forms by the liver and kidneys. These more active forms of Vitamin D improve calcium absorption. Many adults living in the U.S. have little or no sun exposure and are low in Vitamin D. We know that specific wavelengths of sunlight called Ultraviolet-B cause Vitamin D to be made in the skin.

Condition Intervention
Vitamin D Deficiency Behavioral: Sun Exposure

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Sunlight Exposures Effect on Serum Vitamin D Levels

Resource links provided by NLM:


Further study details as provided by Creighton University:

Primary Outcome Measures:
  • The goal of this study is to correlate vitamin D response and 25(OH)D response to sun exposure with most of the body (90 %) exposed to 0.25 hour of July sunlight at 41.2º N latitude and at approximately 1-2 pm in the afternoon. [ Time Frame: 1 week ]

Enrollment: 6
Study Start Date: July 2007
Study Completion Date: September 2007
Primary Completion Date: September 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1
All subjects in this study will be in the active arm
Behavioral: Sun Exposure
Each subject will wear a swimming suit and be exposed to sunlight for 30 minutes total (15 minutes lying on back, 15 minutes lying on stomach).

Detailed Description:
At the beginning of the study we will measure your height, weight, skin color, and draw blood to measure your blood levels of Vitamin D and 25-hydroxyvitamin D. Each subject will wear a swimming suit and be exposed to sunlight for 30 minutes total (15 minutes lying on back, 15 minutes lying on stomach).We will draw blood for Vitamin D and 25-hydroxyvitamin D on days 1,2,3,5, and 7 after sunlight exposure. There will be six blood draws for a total of 102 cc of blood drawn (about 3 ½ teaspoons drawn each time).
  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   19 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • healthy males or females ages19-50 with "light" skin (self-assessed as Fitzpatrick skin type I-III) with minimal sun exposure and exogenous sources of vitamin D.

Exclusion Criteria:

  • less than 16 oz milk per day, less than 10 hours of sun per week, no Vitamin D supplements, no anticonvulsants, no barbiturates, no steroids, no meds that increase photosensitivity, no granulomatous disease, no liver or kidney disease, no history of skin cancer, and BMI less than 30.
  Contacts and Locations
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): NCT00473317


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

Responsible Party: Laura Armas, Creighton University
ClinicalTrials.gov Identifier: NCT00473317     History of Changes
Other Study ID Numbers: Creighton3
First Submitted: May 11, 2007
First Posted: May 15, 2007
Last Update Posted: April 1, 2008
Last Verified: March 2008

Keywords provided by Creighton University:
sunlight
UVB
Vitamin D

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