The copper content of foods based on a critical evaluation of published analytical data

Abstract Increasing interest in the copper (Cu) intake of Americans has generated a need for the compilation, evaluation, and improvement of data for Cu in foods. In order to estimate dietary Cu intake, accurate and precise Cu values for foods are needed. A system of criteria developed to evaluate the quality of published selenium data has been adapted to evaluate analytical data for Cu in foods. Mean Cu values for each food were calculated from the evaluated data and combined with USDA frequency of consumption data, resulting in a list of 218 major contributors of dietary Cu. The richest sources of Cu are legumes, wheat bran cereals, organ meats, shellfish, and grains. Confidence codes, indicators of the relative degree of confidence the user of the data can have in that mean value, were included. More than half of the mean values for the foods listed are of limited quality or result from a limited quantity of data, indicating a need for improvement in food Cu data. This proposed dynamic system for the compilation and evaluation of Cu data can be used to generate Cu data bases for specific purposes, provide a ranked list of foods which are significant contributors of that nutrient, and establish priorities for further improvements in the database.