Vitamin D Supplementation and Upper Respiratory Tract Infections in Adolescent Swimmers

Upper Respiratory Tract Infections Clinical Trial

Official title:

Vitamin D Supplementation, Upper Respiratory Tract Infections, Immune and Physical Functions in Adolescent Swimmers

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01215682
• Other study ID #: SHEBA-10-7762-GDR-CTIL
• Status: Completed
• Phase: N/A
• First received: October 5, 2010
• Last updated: March 22, 2012
• Start date: October 2010
• Est. completion date: March 2011

Study information

• Verified date: March 2012
• Source: Sheba Medical Center
• Contact: n/a
• Is FDA regulated: No
• Health authority: Israel: Israeli Health Ministry Pharmaceutical Administration
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 82
• Est. completion date: March 2011
• Est. primary completion date: March 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 12 Years to 18 Years

Eligibility

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 Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Prevention

Related Conditions & MeSH terms

• Communicable Diseases
• Infection
• Respiratory Tract Infections
• Upper Respiratory Tract Infections

Intervention

Dietary Supplement:
• vitamin D
2000 IU/day of vitamin D3 as a once-daily dose
• placebo
sweetened water

Locations

Country	Name	City	State
Israel	Maccabi Haifa Swimming Club	Haifa
Israel	Bnei Herzlyia Swimming Club	Herzlyia
Israel	Hod Hasharon Swimming Club	Hod Hasharon
Israel	Maccabim-Reut Swimming Club	Maccabim

Sponsors (1)

Lead Sponsor	Collaborator
Sheba Medical Center

Country where clinical trial is conducted

Israel, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	URI frequency	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	No
Primary	URI duration	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	No
Primary	UTI severity	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	No
Secondary	plasma vitamin D levels		3 months	No
Secondary	immune system function	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	No
Secondary	physical function	absence from school or training, land and swimming fitness tests. Comparison will be made with changes in vitamin D levels.	3 months	No