Please select the arm or intervention descriptions that belong to the clinical trial below.
Title: Vitamin D Supplementation, Upper Respiratory Tract Infections, Immune and Physical Functions in Adolescent Swimmers
Brief 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.


Options:
A: Arm Label: Mindfulness Meditation; Type: EXPERIMENTAL; Interventions: Other: Mindfulness Meditation | Arm Label: Exercise; Type: EXPERIMENTAL; Interventions: Other: Exercise | Arm Label: Wait-list control; Type: NO_INTERVENTION; Interventions: N/A | Intervention Type: OTHER; Name: Mindfulness Meditation; Assigned to Arm(s): Mindfulness Meditation | Intervention Type: OTHER; Name: Exercise; Assigned to Arm(s): Exercise
B: Arm Label: Physical Activity; Type: ACTIVE_COMPARATOR; Interventions: Behavioral: Physical Activity | Arm Label: Successful Aging; Type: ACTIVE_COMPARATOR; Interventions: Behavioral: Successful Aging | Intervention Type: BEHAVIORAL; Name: Physical Activity; Assigned to Arm(s): Physical Activity | Intervention Type: BEHAVIORAL; Name: Successful Aging; Assigned to Arm(s): Successful Aging
C: Arm Label: vit D; Type: ACTIVE_COMPARATOR; Interventions: Dietary Supplement: vitamin D | Arm Label: placebo; Type: PLACEBO_COMPARATOR; Interventions: Dietary Supplement: placebo | Intervention Type: DIETARY_SUPPLEMENT; Name: vitamin D; Assigned to Arm(s): vit D | Intervention Type: DIETARY_SUPPLEMENT; Name: placebo; Assigned to Arm(s): placebo
D: Arm Label: Physiotherapy+conventional treatment; Type: EXPERIMENTAL; Interventions: Other: Physiotherapy+conventional treatment | Arm Label: Conventional treatment; Type: ACTIVE_COMPARATOR; Interventions: Drug: Conventional treatment | Intervention Type: OTHER; Name: Physiotherapy+conventional treatment; Assigned to Arm(s): Physiotherapy+conventional treatment | Intervention Type: DRUG; Name: Conventional treatment; Assigned to Arm(s): Conventional treatment

Answer: C