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Human Lung Responses to Respiratory Pathogens

This study has been completed.
National Institute of Allergy and Infectious Diseases (NIAID)
Information provided by (Responsible Party):
Alicia Gerke, University of Iowa Identifier:
First received: October 17, 2013
Last updated: November 8, 2013
Last verified: November 2013

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.

Condition Intervention Phase
Respiratory Infection
Dietary Supplement: Vitamin D3 (cholecalciferol)
Dietary Supplement: Placebo Sugar Pill
Phase 1
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator)
Primary Purpose: Basic Science
Official Title: Human Lung Responses to Respiratory Pathogens

Resource links provided by NLM:

Further study details as provided by University of Iowa:

Primary Outcome Measures:
  • Differential gene expression of the alveolar macrophage by microarray analysis [ Time Frame: 3 months ]

Enrollment: 105
Study Start Date: June 2007
Study Completion Date: October 2010
Primary Completion Date: July 2010 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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


Ages Eligible for Study:   18 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

Signed informed consent form Age 18 - 60 Healthy nonsmoker, healthy smoker FEV1 (for smokers) > 60% predicted.

Exclusion Criteria:

  • Pregnant or breastfeeding
  • Medications (with the exception of hormonal birth control, thyroid medication or prespecified over the counter medications), including multi-vitamins and any preparation that contains vitamin D
  • Asthma
  • Heart disease
  • Diabetes
  • Previous positive tuberculin skin test, or previous diagnosis of tuberculosis
  • Recent respiratory tract infection
  • History of multiple bouts of pneumonia
  • Allergies to caines, atropine, or a history of adverse reaction to narcotics
  • Other factors that increase the risk of bronchoscopy
  • Evidence of acute bronchitis within the past 2 weeks
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Please refer to this study by its identifier: NCT01967628

United States, Iowa
University of Iowa
Iowa City, Iowa, United States, 52242
Sponsors and Collaborators
University of Iowa
National Institute of Allergy and Infectious Diseases (NIAID)
Principal Investigator: Alicia K Gerke, MD University of Iowa
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Alicia Gerke, Assistant Professor, University of Iowa Identifier: NCT01967628     History of Changes
Other Study ID Numbers: DMID 06-0003
Study First Received: October 17, 2013
Last Updated: November 8, 2013

Keywords provided by University of Iowa:
Vitamin D
Respiratory infection
Innate immunity

Additional relevant MeSH terms:
Respiratory Tract Infections
Respiratory Tract Diseases
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on March 29, 2017