A computer-based approach for assessing dietary supplement use in conjunction with dietary recalls

In response to the need to assess both food and supplemental sources of nutrients, we have expanded the capabilities of nutrition data system for research (NDSR) software to allow for assessing dietary supplement use. A Dietary Supplement Assessment Module allows for the automated collection and coding of dietary supplement use. The module is designed for use in conjunction with the software's 24-hour dietary recall features. The medication inventory method, commonly used in pharmaceutical research, served as the basis for the module's assessment approach. In adapting this approach for use in our software we designed a tiered structure that involves first screening for use of dietary supplements, then collecting product detail (e.g. full name of product, number of times taken, etc.), and finally reviewing the information with the participant. Results from a demonstration study conducted to evaluate the module indicate the assessment approach is acceptable to both participants and interviewers. Collecting dietary supplement use information significantly increases interview time, especially for those using multiple products. A validation study is needed to determine whether the new method results in accurate estimation of nutrient intake from supplemental sources.