Effects of Antarctic Environment on Vitamin D Status and Health Risk Biomarkers of Its Inhabitants

Study Overview
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Brief Summary
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The purpose of this study is to evaluate vitamin D (VD) deficiency in the population of Chilean Antarctica and evaluate the efficacy and safety of VD supplementation to decrease VD deficiency and favorably influence biomarkers for bone, cardiovascular, and immune health risk in the inhabitants of Chilean Antarctica.

Detailed Description
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The present study consists of an initial cross-sectional evaluation of VD status and specific health biomarkers in inhabitants of Chilean Antarctica, followed by a randomized controlled trial evaluating two acceptable approaches of vitamin D supplementation (cholecalciferol 600 IU daily vs. 25000 IU weekly) in Antarctic inhabitants.

Official Title
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Effects of Antarctic Environment on Vitamin D Status and Health Risk Biomarkers of Its Inhabitants

Conditions
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Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: cholecalciferol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: population of all ages living in the Chilean Antarctic territory during at least 3 months. Exclusion Criteria: acute or chronic renal disease hyper or hypocalcemia osteomalacia or Paget's disease of bone use of VD supplements or fish oil supplements in the past month in doses higher than 400 IU daily treatment for known VD deficiency in the last 6 months UV phototherapy in the past month.

Ages Eligible for Study
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Maximum Age: 100 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard daily vitamin D3<br>Cholecalciferol 600 IU daily during one year or exit from Antarctica. | Dietary Supplement: cholecalciferol<br>* Administration of vitamin D3<br>* Other names: Vitamin D3;|
| Active Comparator: Higher weekly vitamin D3<br>Cholecalciferol 25000 IU once weekly during one year or exit from Antarctica. | Dietary Supplement: cholecalciferol<br>* Administration of vitamin D3<br>* Other names: Vitamin D3;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in serum 25-hydroxyvitamin D concentration | In Antarctic inhabitants not supplemented with VD that exit Antarctica before start of RCT phase of study. | at end of Antarctic residency or 1 year (90-365 days), whichever came first | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| sun exposure | questionnaires | at 0, 6, 12 months of Antarctic residency | 
| sleep pattern | questionnaires | at 0, 6, 12 months of Antarctic residency | 
| food intake of VD | Food frequency questionnaire | at 0, 6, 12 months of Antarctic residency | 
| serum biomarkers for bone metabolism | intact PTH, calcium phosphorus, alkaline phosphatases, VD-binding protein | at baseline and every 3 months during supplementation (3,6,9,12 months) up to end of Antarctic residency or 1 year (90-365 days), whichever came first | 
| serum high-sensitivity C-reactive protein (hsCRP) |  | at baseline and every 3 months during supplementation (3,6,9,12 months) up to end of Antarctic residency or 1 year (90-365 days), whichever came first | 
| serum cathelicidin (LL-37) concentration |  | at baseline and every 3 months during supplementation (3,6,9,12 months) up to end of Antarctic residency or 1 year (90-365 days), whichever came first | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Vitamin D, cholecalciferol, Antarctica, Chile, cathelicidin, bone metabolism, cardiovascular risk