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Sunlight Exposures Effect on Serum Vitamin D Levels

This study has been completed.
Information provided by:
Creighton University Identifier:
First received: May 11, 2007
Last updated: March 30, 2008
Last verified: March 2008
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: 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).

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

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.
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Please refer to this study by its identifier: NCT00473317

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

Responsible Party: Laura Armas, Creighton University Identifier: NCT00473317     History of Changes
Other Study ID Numbers: Creighton3
Study First Received: May 11, 2007
Last Updated: March 30, 2008

Keywords provided by Creighton University:
Vitamin D

Additional relevant MeSH terms:
Vitamin D Deficiency
Deficiency Diseases
Nutrition Disorders
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on May 23, 2017