Creating a single combined composition table for foods and dietary supplements

Traditionally, developers of nutrient composition databases have maintained separate databases for foods and supplements. Here we present a methodology for combining these two databases with the evaluated advantages and disadvantages of such a conversion. A combined database will have several advantages: eliminating the need to distinguish between a supplement and a food; adding the ability to create recipes for foods with added nutrients and for supplements which are combinations of multiple tablets or ingredients; permitting quantification of nutrient intakes from herbal supplements and food extracts used as supplements; facilitating analysis of naturally occurring nutrients versus added nutrients; and simplifying database maintenance. Several challenges were identified in this process including the need to resolve differing units for nutrients in foods and supplements and the time and cost of the conversion. We concluded the conversion to a combined database is essential if we are to increase the accuracy of our estimates of total dietary intake.