Assessment of carotenoid intakes in humans

The availability of new food composition carotenoid values for fruits and vegetables increases our ability to test hypotheses concerning the role of antioxidant nutrients and cancer risk. To estimate the usual carotenoid intakes, a quantitative diet history covering a one-year period is recommended for epidemiologic studies on diet and cancer. The particular food items in the diet history questionnaire should be representative of the eating patterns of the study population, should contribute more than 85% of the individual carotenoid intakes, and should distinguish between the high and low consumers of particular carotenoids.