Human Lung Responses to Respiratory Pathogens
For most individuals, the lung has a remarkable ability to deal with exposure to a variety of inhaled bacteria. Some individuals, however, do have recurrent bacterial infections, usually in the form of acute or chronic bronchitis and, in some instances, pneumonia. The reasons for this variability in bacterial infections between otherwise healthy subjects, between types of lung disease, and within the same type of lung disease are poorly understood.
Variability in susceptibility to bacterial infections is partially explained by differences in exposure to infectious agents, genetic susceptibility and innate (or early) immune responses. It is of interest that the incidence and severity of bacterial infections is greatest during the winter months. Other than viral infections, there are few variables that change with season. Vitamin D is one known immune modulator with a seasonal periodicity. The hypothesis of this study is that levels of vitamin D are an important determinant of the innate defense of the lung against inhaled bacteria. The investigators further postulate that vitamin D has effects on the innate immune function of both alveolar macrophages and lung epithelial cells.
|Respiratory Infection||Dietary Supplement: Vitamin D3 (cholecalciferol) Dietary Supplement: Placebo Sugar Pill||Phase 1 Phase 2|
|Study Design:||Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary Purpose: Basic Science
|Official Title:||Human Lung Responses to Respiratory Pathogens|
- Differential gene expression of the alveolar macrophage by microarray analysis [ Time Frame: 3 months ]
|Study Start Date:||June 2007|
|Study Completion Date:||October 2010|
|Primary Completion Date:||July 2010 (Final data collection date for primary outcome measure)|
Experimental: Vitamin D3
Vitamin D3 (1000 IUs) daily for 3 months.
|Dietary Supplement: Vitamin D3 (cholecalciferol)|
Placebo Comparator: Sugar capsule
Placebo comparator made of sugar in a capsule
|Dietary Supplement: Placebo Sugar Pill|
Please refer to this study by its ClinicalTrials.gov identifier: NCT01967628
|United States, Iowa|
|University of Iowa|
|Iowa City, Iowa, United States, 52242|
|Principal Investigator:||Alicia K Gerke, MD||University of Iowa|