2009 Annual Report
1a.Objectives (from AD-416)
To acquire and develop representative and accurate compositional values for nutrients and other nutritional components in dietary supplements. To develop a generic data documentation and evaluation system to assess the quality of data for nutritional supplements, to provide for the continuous monitoring of dietary supplement composition data, to establish guidelines for the generation and dissemination of high quality data.
1b.Approach (from AD-416)
This project will develop and implement an expert system to evaluate the quality and representativeness of existing estimates for specific nutrients in nutritional supplements. Priorities for new nutrient analyses will be identified and ranked for those supplements which contribute up to 80% of the intake of specific nutrients for a representative sample of the U.S. population. Where nutrient data are inadequate for high priority dietary supplements, new values will be generated by analytical determination, calculation, or consultation with the dietary supplement industry. Samples of supplements to be analyzed will be selected using a probability-based approach and nationwide sampling. Valid chemical methods including rigorous analytical quality control will be employed. Effective modes of data dissemination will be developed to address the needs of data users.
During the final five months of the project, Nutrient Data Laboratory (NDL) scientists reviewed final analytical data for the adult multi-vitamin mineral (MVM) study. Statistical analysis of data was initiated to provide generic estimates for 19 nutrients in commonly consumed MVM product types. During this period children's supplements were identified, sampled nationwide, and prepared for analysis for up to 22 nutrients. NDL initiated planning for the development of the Dietary Supplement Ingredient Database (DSID) website.
Since project was initiated, NDL has worked with the Office of Dietary Supplements, National Institutes of Health, to develop the DSID to support the needs of the public health research community. The goal of the DSID has been to report levels of nutrients and other bioactive components in dietary supplements (DS). The foundation of the DS database is analytical data, using an approach similar to that used in USDA food databases. Initially, studies were conducted to develop procedures for samples handling, to select qualified laboratories, to evaluate methods for analysis, and to develop quality control procedures for nutrients in a multivitamin/mineral (MVM) matrix and for ingredients in caffeine-containing supplements. Two peer-reviewed manuscripts were published in 2008: the results of the adult MVM pilot studies and the study of caffeine levels in 53 dietary supplements.
The Percent Daily Value (%DV) study was conducted to test for systematic relationships between label and analytical values for 23 nutrients in 18 to 24 adult multivitamin/minerals (MVMs). Findings from the pilot studies and %DV study were used to plan further research. The %DV study data were used to test statistical regression predictions developed in the adult MVM study described below.
A comprehensive adult MVM study was conducted to determine nutrient values for representative products to estimate content and assess variability in products selected nationwide. More than one hundred adult MVM products were selected and analyzed for 19 nutrients. As mentioned above sixty-five children’s MVM products were also analyzed for 19 nutrients. Next, a study of omega-3 fatty acid content in 20 commonly reported fish oil and flaxseed oil supplements was initiated. For each of these studies, statistical sampling plans were developed using data from the National Health and Nutrition Examination Survey (NHANES) and current market sources to identify representative products and major market channels. Quality control was monitored using validated laboratory methods, reference materials, and duplicate analysis.
NDL scientists communicated progress of the DSID studies at a number of national scientific meetings and at meetings of the dietary supplement industry to educate and inform stakeholders regarding DSID research. NDL presented the results of control material analyses and actively participated in planning two ODS-sponsored workshops on analytical vitamin methodology and on mineral methodology in dietary supplements. Two federal stakeholder meetings were organized to receive input from researchers, with attendees from 16 federal agencies.
Completion of nationwide adult Multivitamin/mineral (MVM) study. The objectives of the nationwide adult multivitamin/mineral (MVM) study were to obtain nationally representative estimates for high priority vitamins and minerals in commonly reported adult MVMs (n >2 vitamins) and to assess variability within and among products. The study included chemical analysis of thirty-five most commonly reported adult MVM products and seventy-five representative lower market share products purchased in six geographic locations from various market channels and analyzed at qualified laboratories for 22 nutrients and for disintegration testing. Statistical data analysis was finalized for 18 nutrients in adult MVM products. These data are to be used as the basis for the Dietary Supplement Ingredient Database, Release 1 (DSID-1).
5.Significant Activities that Support Special Target Populations
Dietary supplements are consumed by populations in various ethnic, socioeconomic, and other vulnerable groups. For example, DSID began a study of children’s multivitamin/mineral (MVM) supplements. Data acquired through DSID studies will be used to monitor total dietary intake and health status of various sub-populations. The nationwide sampling program was designed to select sample units from all marketing channels (retail, grocery, drug, multi-level) and from a large selection of known or popular brands to assure that products purchased by diverse populations are covered.