Vitamin D Deficiency
Conditions
Keywords
Vitamin D, cholecalciferol, Antarctica, Chile, cathelicidin, bone metabolism, cardiovascular risk
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.
Interventions
DIETARY_SUPPLEMENTcholecalciferol
Administration of vitamin D3
Sponsors
Fuerza Aérea de Chile
Instituto Antártico Chileno
Harvard Medical School (HMS and HSDM)
Pontificia Universidad Catolica de Chile
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
No minimum to 100 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| sleep pattern | at 0, 6, 12 months of Antarctic residency | questionnaires |
| food intake of VD | at 0, 6, 12 months of Antarctic residency | Food frequency questionnaire |
| sun exposure | at 0, 6, 12 months of Antarctic residency | questionnaires |
| 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 | — |
| 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 |
Outcome results
None listed