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. Preliminary results from a demonstration study being 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.

Enhancing data on nutrient composition of foods eaten by participants in the INTERMAP study in China, Japan, the United Kingdom, and the United States.

The International Study of Macronutrients and Blood Pressure (INTERMAP) is a four-country study investigating relationships between individual dietary intakes and blood pressure. Dietary intake patterns of individuals were estimated for macronutrients (proteins, lipids, carbohydrates, alcohol) and their components (amino acids, fatty acids, starch), as well as minerals, vitamins, caffeine, and dietary fiber. The dietary assessment phase of the study involved collection of four 24-h recalls and two 24-h urine specimens from each of 4680 adults, ages 40-59, at 16 centers located in the People's Republic of China, Japan, the United Kingdom and the United States. For each country, an available database of nutrient composition of locally consumed foods was updated for use in the analysis of dietary data collected within the country. The four original databases differed in number and types of foods and nutrients included, analytic methods used to derive nutrients, and percentage of missing nutrient values. The Nutrition Coordinating Center at the University of Minnesota updated the original databases in several ways to overcome the foregoing limitations and increase comparability in the analyses of nutrient intake of individuals across the four countries: (1) addition of new foods and preparation methods reported by study participants; (2) addition of missing nutrient fields important to the study objectives; (3) imputation of missing nutrient values to provide complete nutrient data for each food reported by participants; and (4) use of adjustment factors to enhance comparability among estimates of nutrient intake obtained through each country's nutrient-coding methodology. It was possible to expand, enhance, and adjust the nutrient databases from the four countries to produce comparable (60 nutrients) or nearly comparable (ten nutrients) data on composition of all foods reported by INTERMAP participants.