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

Not Applicable

Completed

• Conditions: Vitamin D Deficiency
• Interventions: Dietary Supplement: cholecalciferol

• Registration Number: NCT02930434
• Lead Sponsor: Pontificia Universidad Catolica de Chile

Brief Summary

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

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.

Study Timeline

• Study Start: 2016-10
• Study First Submitted: 2016-10-10
• Study First Submitted QC: 2016-10-10
• Study First Posted: 2016-10-12
• Primary Completion: 2017-12-10
• Status Verified: 2018-03
• Study Completion: 2018-03-01
• Last Update Submitted: 2018-03-11
• Last Update Posted: 2018-03-13

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 75

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Standard daily vitamin D3	cholecalciferol	Cholecalciferol 600 IU daily during one year or exit from Antarctica.
Higher weekly vitamin D3	cholecalciferol	Cholecalciferol 25000 IU once weekly during one year or exit from Antarctica.

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
sleep pattern	at 0, 6, 12 months of Antarctic residency	questionnaires
sun exposure	at 0, 6, 12 months of Antarctic residency	questionnaires
food intake of VD	at 0, 6, 12 months of Antarctic residency	Food frequency questionnaire
serum biomarkers for bone metabolism	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	intact PTH, calcium phosphorus, alkaline phosphatases, VD-binding protein
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