The VITamin D and OmegA-3 TriaL (VITAL; NCT 01169259) is an ongoing randomized clinical trial in 25,871 U.S. men and women investigating whether taking daily dietary supplements of vitamin D3 (2000 IU) or omega-3 fatty acids (Omacor® fish oil, 1 gram) reduces the risk of developing cancer, heart disease, and stroke in people who do not have a prior history of these illnesses.

This ancillary study is being conducted among participants in VITAL and will examine whether vitamin D or fish oil reduces respiratory morbidity, including COPD and asthma exacerbations, the risk of pneumonia, and airflow obstruction/decline of pulmonary function; and whether either of these interventions improves asthma control.

Chronic obstructive lung disease (COPD) and pneumonia are leading causes of death in United States and worldwide. COPD, which is also a significant source of disability, is increasing in prevalence. Approximately 14 million adults have asthma, which leads to approximately 12 million missed work days per year in the United States. In adults, COPD and asthma often coexist. Treatment options for COPD are limited, and prevalence of vitamin D deficiency is high. COPD lung disease (COPD, asthma, airflow obstruction), and most COPD additional co-morbidities responsible for COPD progression (e.g., respiratory infections/pneumonia, muscle weakness, cardiac failure) may benefit from vitamin D supplementation therapy, but this requires rigorous testing. Marine omega-3 fatty acids work through different pathways from vitamin D to affect inflammation. Observational studies and clinical trials suggest that consumption of fish and/or fish oil may protect against COPD, asthma or pneumonia, but the data are not consistent. Thus, there is a compelling need for a clinical trial to evaluate the potential benefits or risks of vitamin D and fish oil supplementation on COPD and asthma exacerbations, airflow obstruction and decline of lung function, and risk of pneumonia.

The primary outcomes of interest in Lung VITAL are COPD exacerbations; airflow obstruction and decline of pulmonary function; and pneumonia. Asthma exacerbations and asthma control are secondary outcomes. A tertiary goal is to assess whether the effects of the interventions differ by baseline dietary intake or baseline blood levels of the nutrients.

Depending on the primary outcome, Lung VITAL will be conducted among all participants in VITAL (NCT 01169259), or in subsets of the VITAL population who were followed by detailed respiratory questionnaire and/or lung function testing.

• This study is open to all VITAL participants (NCT 01169259). Population includes men 50 years of age or older and women 55 years of age or older in the United States
• Participants who live in selected metropolitan areas of the U.S. (where we set up the infrastructure for clinic or home visits), are eligible for pulmonary function measurements.