Sources of data for developing and maintaining a nutrient database.

A nutrient database that contains current, reliable data is a prerequisite for accurate calculation of dietary intakes. Most nutrient databases are expanded from data supplied by the U.S. Department of Agriculture and may include additional foods or nutrients or data from more recent analyses, food manufacturers, or foreign food tables. Guidelines must be established for selection of reliable values from appropriate sources. A system for precise documentation of data sources provides a means for determining whether individual nutrient values were derived from chemical analyses, recipe calculations, or imputations. This article identifies data sources used by the Nutrition Coordinating Center at the University of Minnesota for its nutrient database and describes the procedures used to select and document nutrient values.