Nutrient sources of provitamin A carotenoids in the American diet.

The food sources of provitamin A carotenoids were estimated from data from the Second National Health and Nutrition Examination Survey (NHANES II) carried out in 1976-1980. Carrots contribute over 30% of total population intake. Dark green leafy vegetables and sweet potatoes are also major contributors. However, several items often omitted from questionnaires to assess carotenoids are also major contributors, including salad, orange juice, beef stew, and milk. Conversely, many foods often included on such questionnaires are unimportant contributors, including papayas, plums, okra, and grapes. Recent changes in databases or food habits might change some rankings, but are unlikely to change the items in a list covering the top 90% of provitamin A intake. Questionnaires should include the important sources and exclude trivial sources, to minimize misclassification.