Environmental Influences on Vitamin D Status (Alaska/Hawaii)
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Purpose
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. However, the relative influences of each are largely unknown and we cannot reliably answer the question of how much sun exposure an individual needs at various latitudes and at various seasons in order to ensure normal vitamin D status.
| Condition |
|---|
|
Vitamin D Deficiency |
| Study Type: | Observational |
| Study Design: | Observational Model: Cohort Time Perspective: Cross-Sectional |
| Official Title: | Environmental Influences on Vitamin D Status |
- To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes [ Time Frame: crosssectional ] [ Designated as safety issue: No ]
- 2. To collect information on variables that influence Vitamin D status such to collect information on skin color, history of sun exposure and sunscreen use, diet history, vitamin and calcium supplements used, and BMI. [ Time Frame: cross sectional ] [ Designated as safety issue: No ]
- To collect a blood sample for DNA analysis of inter-individual differences in Vitamin D metabolism (Gc or Vitamin D binding protein alleles). [ Time Frame: cross sectional ] [ Designated as safety issue: No ]
| Enrollment: | 50 |
| Study Start Date: | July 2008 |
| Study Completion Date: | August 2008 |
| Primary Completion Date: | August 2008 (Final data collection date for primary outcome measure) |
| Groups/Cohorts |
|---|
|
Alaska residents
50 "healthy" community dwelling males or females.
|
|
Hawaiian residents
50 "healthy" community dwelling males or females at each site
|
Detailed Description:
Purpose of the study: To determine the effect of environmental influences on Vitamin D status.
Specific Aims
- To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes (Alaska and Hawaii).
- To collect information on variables that influence Vitamin D status such as skin color, history of sun exposure and sunscreen use, diet history, vitamin and calcium supplements used, and BMI.
- To collect typical food samples from the region for future analysis of their Vitamin D and 25D content.
- To collect a blood sample for DNA analysis of inter-individual differences in Vitamin D metabolism (Gc or Vitamin D binding protein alleles).
Eligibility| Ages Eligible for Study: | 18 Years to 60 Years |
| Genders Eligible for Study: | Both |
| Accepts Healthy Volunteers: | Yes |
| Sampling Method: | Non-Probability Sample |
Age of Subjects: The subjects will be between ages 18-60. The upper age is limited to age 60 as aging skin is less able to make vitamin D, therefore a separate study of elderly people would be more appropriate.
Racial and Ethnic Origin: Both sites have a diverse ethnic and racial population and the subjects will be as representative of the population as possible.
Inclusion Criteria:
- Able to consent and come for a study visit. Male or female males and females ages 18-60.
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.
Contacts and Locations| United States, Alaska | |
| Alaska Kidney and Diabetes Associates | |
| Anchorage, Alaska, United States, 99508 | |
| Principal Investigator: | Laura A Armas, MD | Creighton University |
More Information
No publications provided
| Responsible Party: | Laura Armas, M D, Creighton University |
| ClinicalTrials.gov Identifier: | NCT00780247 History of Changes |
| Other Study ID Numbers: | Creighton6, WIRB approval 20080712 |
| Study First Received: | October 24, 2008 |
| Last Updated: | October 24, 2008 |
| Health Authority: | United States: Institutional Review Board |
Keywords provided by Creighton University:
|
Vitamin D Sun Latitude Vitamin D status |
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 May 19, 2013