Vitamin D Supplementation and Upper Respiratory Tract Infections in Adolescent Swimmers
Vitamin D Supplementation, Upper Respiratory Tract Infections, Immune and Physical Functions in Adolescent Swimmers
Background: The medical and economic burden of upper respiratory tract infections (URTIs) is extremely high, while prevention and treatment options are limited. Therefore, there is a constant need for new methods in order to significantly decrease such morbidity. Extensive evidence shows that vitamin D is associated with respiratory health, including in the prevention and treatment of URTIs. Competitive swimmers have a high prevalence of URTIs, and can serve as a model for research in this field.
The study hypothesis is that vitamin D supplementation to young swimmers with low vitamin D levels will reduce the frequency, length, and severity of URTIs and their accompanying functional impairment, while improving cellular immune function and physical function.
Methods: After screening 100 competitive adolescent swimmers to obtain ~60 with low serum levels of vitamin D, this study group will be randomized to receive either vitamin D supplementation (2000 IU/d) or placebo, given in a double blinded fashion for three months. Participants will fill a daily questionnaire regarding frequency, length and severity of URTIs symptoms and functional impairment. Blood will be drawn to evaluate changes in vitamin D status (25(OH)D) and immune function among study participants at the beginning of the study and after supplementation. Physical function on land and in water will also be assessed.
Expected results: Increase in serum 25(OH)D levels following supplementation will significantly decrease the frequency, length and severity of URTI's and their functional impairment, while enhancing the cellular immune system function and physical capacity.
Study Overview
Status
Status
Conditions
Conditions
Intervention / Treatment
Intervention / Treatment
Study Type
Study Type
Enrollment (Actual)
Enrollment
Phase
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
-
Haifa, Israel
- Maccabi Haifa Swimming Club
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Herzlyia, Israel
- Bnei Herzlyia Swimming Club
-
Hod Hasharon, Israel
- Hod Hasharon Swimming Club
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Maccabim, Israel
- Maccabim-Reut Swimming Club
-
-
Participation Criteria
Eligibility Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- members of swimming team
- training at least 15 hours/week
- low vitamin D plasma levels (<30 ng/ml)
- signed consent forms
Exclusion Criteria:
- chronic health conditions
- taking prescription medications
- taking diet supplementations
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Prevention
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Quadruple
Number of Arms
Arms and Interventions
Participant Group / ArmParticipant Group / Arm |
Intervention / TreatmentIntervention / Treatment |
|---|---|
|
Placebo Comparator: placebo
|
sweetened water
|
|
Active Comparator: vit D
|
2000 IU/day of vitamin D3 as a once-daily dose
|
What is the study measuring?
Primary Outcome Measures
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
URI frequency
Time Frame: 3 months
|
URI frequency will be measured in both groups, starting 4 weeks after initiating the suplementation.
Analysis will also assess differences by sex or initial vitamin D levels, as well as by immune function changes.
|
3 months
|
|
URI duration
Time Frame: 3 months
|
URI duration will be measured in both groups, starting 4 weeks after initiating the suplementation.
Analysis will also assess differences by sex or initial vitamin D levels, as well as by immune function changes.
|
3 months
|
|
UTI severity
Time Frame: 3 months
|
URI severity will be measured in both groups, starting 4 weeks after initiating the suplementation.
Analysis will also assess differences by sex or initial vitamin D levels, as well as by immune function changes.
|
3 months
|
Secondary Outcome Measures
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
plasma vitamin D levels
Time Frame: 3 months
|
3 months
|
|
|
immune system function
Time Frame: 3 months
|
T-cell receptor excision circles (TREC), T cell receptor repertoire, B-cell receptor excision circles (BREC).
Comparison will be made with changes in vitamin D levels and with URI characteristics.
|
3 months
|
|
physical function
Time Frame: 3 months
|
absence from school or training, land and swimming fitness tests.
Comparison will be made with changes in vitamin D levels.
|
3 months
|
Collaborators and Investigators
Sponsor
Sponsor
Investigators
Investigators
- Principal Investigator: Gal Dubnov-Raz, MD MSc, Sheba Medical Center
- Principal Investigator: Naama W Constantini, MD, Hadassah Medical Organziation
- Principal Investigator: Avner Cohen, MD, Clalit Health Services
- Principal Investigator: Raz Somech, MD PhD, Sheba Medical Center
Publications and helpful links
Study record dates
Study Major Dates
Study Start
Study Start
Primary Completion (Actual)
Primary Completion
Study Completion (Actual)
Study Completion
Study Registration Dates
First Submitted
First Submitted
First Submitted That Met QC Criteria
First Submitted That Met QC Criteria
First Posted (Estimate)
First Posted
Study Record Updates
Last Update Posted (Estimate)
Last Update Posted
Last Update Submitted That Met QC Criteria
Last Update Submitted That Met QC Criteria
Last Verified
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
Other Study ID Numbers
- SHEBA-10-7762-GDR-CTIL
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