Does dietary vitamin A protect against airway obstruction? The Atherosclerosis Risk in Communities (ARIC) Study Investigators.
A recent report based on data from the first National Health and Nutrition Examination Survey suggested that low intake of vitamin A may be associated with a greater risk of airway obstruction. We attempted to replicate these findings in a population-based sample of middle-aged adults (n = 15,743) who participated in the baseline examination of the Atherosclerosis Risk in Communities (ARIC) Study. Vitamin A intake was estimated from a 66-item food frequency questionnaire, and the presence of airway obstruction was determined by spirometry. Although airway obstruction was associated in ARIC with well-established risk factors such as age, sex, and smoking, there was little evidence for a role of vitamin A. With only one exception, vitamin A intake was unrelated to airway obstruction in all smoking categories using either categorical or continuous measures of lung function (FEV1, FVC, FEV1/FVC). Only among current smokers in the upper tertile of lifetime cigarette smoking (> 41 pack-years) was the odds ratio of having airway obstruction for the lowest quartile of vitamin A intake compared with the highest quartile elevated (1.7 [95% confidence interval 1.1 to 2.7]). Despite some biological plausibility that vitamin A intake may prevent obstructive lung disease, the inability to demonstrate association in a larger population study, with better estimation of usual dietary intake, casts doubt on the existence of causal relationship.
Shahar
E
E
Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55454-1015.
Folsom
A R
AR
Melnick
S L
SL
Tockman
M S
MS
Comstock
G W
GW
Shimakawa
T
T
Higgins
M W
MW
Sorlie
P D
PD
Szklo
M
M
D000402:Airway Obstruction / Q000453:epidemiology / Q000517:prevention & control*; D001161:Arteriosclerosis / Q000453:epidemiology; D016001:Confidence Intervals; D004032:Diet / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008396:Maryland / Q000453:epidemiology; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D008922:Mississippi / Q000453:epidemiology; D009657:North Carolina / Q000453:epidemiology; D016017:Odds Ratio; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014801:Vitamin A / Q000008:administration & dosage*
D014801:Vitamin A