Diet and vitamin D as risk factors for lung impairment and COPD.

Epidemiologic and observational studies have shown an association between increased intakes of certain micronutrients and higher levels of lung function and health. The National Health and Nutrition Examination Surveys of the U.S. population have demonstrated repeatedly that increased intakes or serum levels of some micronutrients, including the vitamins E, D, C, and A, and carotenes are associated positively with forced expiratory volume in 1 second (FEV1). These findings are complemented by other observational studies, including the MORGEN study as well as the Seven Countries Study, both of which found micronutrient status had positive correlations with pulmonary function. In addition, epidemiologic studies have demonstrated that dietary intake patterns with increased intakes of fruit, vegetables, fish, vitamin E, and whole grains have been associated with a decreased development of chronic obstructive pulmonary disease (COPD) in smokers and nonsmokers, higher levels of FEV1, and decreased long-term COPD mortality. Diets high in refined food have been associated with accelerated longitudinal decline in FEV1 over 5 years. Taken together, these results suggest that micronutrient status may impact lung function, and that nutrition interventions could be a useful tool in a public health campaign aimed at the prevention of lung disease. Future research should focus on the effect of nutrition interventions on the natural history of lung disease.