Environmental Influences on Vitamin D Status

Vitamin D Deficiency Clinical Trial

— Alaska/Hawaii  

Official title:

Environmental Influences on Vitamin D Status

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00780247
• Other study ID #: Creighton6
• Secondary ID: WIRB approval 20
• Status: Completed
• Phase: N/A
• First received: October 24, 2008
• Last updated: October 24, 2008
• Start date: July 2008
• Est. completion date: August 2008

Study information

• Verified date: October 2008
• Source: Creighton University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Observational

Clinical 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. 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.

Description:

Purpose of the study: To determine the effect of environmental influences on Vitamin D status.

Specific Aims

1. To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes (Alaska and Hawaii).

2. 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.

3. To collect typical food samples from the region for future analysis of their Vitamin D and 25D content.

4. To collect a blood sample for DNA analysis of inter-individual differences in Vitamin D metabolism (Gc or Vitamin D binding protein alleles).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: August 2008
• Est. primary completion date: August 2008
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 18 Years to 60 Years

Eligibility

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.

Study Design

Observational Model: Cohort, Time Perspective: Cross-Sectional

Related Conditions & MeSH terms

• Vitamin D Deficiency

Locations

Country	Name	City	State
United States	Alaska Kidney and Diabetes Associates	Anchorage	Alaska

Sponsors (2)

Lead Sponsor	Collaborator
Creighton University	Procter and Gamble

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	To measure the prevailing 25D and Vitamin D levels in communities at diverse latitudes		crosssectional	No
Secondary	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.		cross sectional	No
Secondary	To collect a blood sample for DNA analysis of inter-individual differences in Vitamin D metabolism (Gc or Vitamin D binding protein alleles).		cross sectional	No