Research into community acquired pneumonia has traditionally focused on prognosis and on finding the most effective antibiotic treatment. Little attention has been paid to identifying risk factors for this disease, particularly modifiable ones.

A recent prospective cohort study conducted within the nurses' health study II measured the effect of dietary and supplemental intake of individual vitamins on the incidence of a first case of community acquired pneumonia in otherwise healthy well nourished women.1 The participants were 83 165 nurses aged 27-44 in 1991. Dietary information and the occurrence of community acquired pneumonia were assessed every four years through a semi-structured questionnaire. The diagnosis was confirmed by a chest radiograph.

On the basis of 10 years of follow-up and 925 new cases of community acquired pneumonia—and after adjusting for age, body mass index, smoking status, alcohol use, physical activity, and total energy intake—no overall association was found between dietary and supplemental intake of individual vitamins and the incidence of the disease. Subgroup analysis hinted at a possible protective effect of high dietary vitamin E intake in smokers who did not take vitamin …