Vitamin D DeficiencyAlaska/HawaiiNCT00780247
Environmental Influences on Vitamin D Status
An observational study of Vitamin D Deficiency, run by Creighton University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Vitamin D Deficiency
- How many people
- 50 participants
- Where
- 1 siteUnited States
- Study dates
- Jul 2008to Aug 2008
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: 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.
Who may be able to join
- Able to consent and come for a study visit. Male or female males and females ages 18-60.
Who cannot join
- 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.
Trial locations and contacts
1 site in 1 country.
United States1 site
Alaska Kidney and Diabetes Associates
Anchorage, Alaska, 99508
About this study
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.
Read the 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).
- Conditions
- Vitamin D Deficiency
- Keywords
- Vitamin D, Sun, Latitude, Vitamin D status
- Medical subject headings
- Vitamin D Deficiency
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Alaska residents | 50 "healthy" community dwelling males or females. | |
| Hawaiian residents | 50 "healthy" community dwelling males or females at each site |
What is being measured
The primary outcome is the main question the study is designed to answer.
To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes
Measured: crosssectional
Secondary outcomes (2)
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.
Measured: cross sectional
To collect a blood sample for DNA analysis of inter-individual differences in Vitamin D metabolism (Gc or Vitamin D binding protein alleles).
Measured: cross sectional
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Oct 2008 (estimated)
- Study startJul 2008
- Primary completionAug 2008
- Study completionAug 2008
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Vitamin D DeficiencyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Creighton University
- Sponsor type
- University, hospital or other
- Collaborators
- Procter and Gamble
- Investigators
- Laura A Armas, MD, Principal investigator, Creighton University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00780247
- Sponsor's protocol ID
- Creighton6
- Other IDs
- WIRB approval 20080712
- Acronym
- Alaska/Hawaii
- Status last verified
- Oct 2008
- First submitted
- 24 Oct 2008
- Last updated
- 27 Oct 2008
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 27 Oct 2008. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Environmental Influences on Vitamin D Status
- ClinicalTrials.gov ID
- NCT00780247
- Acronym / sponsor ID
- Alaska/Hawaii / Creighton6
- Conditions
- Vitamin D Deficiency
- Keywords
- Vitamin D, Sun, Latitude, Vitamin D status
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Creighton UniversityUniversity, hospital or other
- Collaborators
- Procter and Gamble
- Study start
- Jul 2008
- Primary completion
- Aug 2008 (actual)
- Study completion
- Aug 2008 (actual)
- First posted
- 27 Oct 2008 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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).
Study design
- Observational model
- Cohort
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Alaska residents | – | –50 "healthy" community dwelling males or females. |
| Hawaiian residents | – | –50 "healthy" community dwelling males or females at each site |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- 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.
Key inclusion criteria (1 listed)
- Able to consent and come for a study visit. Male or female males and females ages 18-60.
Key exclusion criteria (1 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes
Time frame: crosssectional
2 secondary outcomes
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
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
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Oct 2008.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Laura A Armas, MD principal investigator
Creighton University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Vitamin D Deficiency, run by Creighton University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 27 Oct 2008. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes (time frame: crosssectional). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Oct 2008.