2010 Annual Report
Objective 1: Determine and monitor the nutrient and other ingredient composition of dietary supplements commonly consumed by Americans. Compile, maintain, and disseminate electronic dietary supplement composition databases utilizing standardized approaches according to specified timelines.
Objective 2: Evaluate and update methods for the acquisition, evaluation, compilation and dissemination of dietary supplement composition data utilizing new, robust computerized systems.
Objective 3: Investigate the variability of dietary supplement composition data attributable to inherent supplement differences, analytical methodology, and other contributing factors.
Objective 2: NDL will develop and validate methods for data acquisition (e.g., USDA analytical data, industry data), including statistical sampling, sample handling, laboratory methodology, and data quality evaluation, to ensure representative and accurate dietary supplement ingredient estimates. For analytical studies managed by NDL, statistical sampling plans for the analysis of dietary supplements will continue to be developed based upon market share and ingredient label information. NDL will include available Standard Reference Materials (SRMs) when sending batches of samples to the laboratory for analysis. NIST recommendations for the analysis of ingredients in SRMs, including stability information and extraction and homogenization procedures will be used in the development and evaluation of NDL laboratory protocols for contracted labs.
Objective 3: NDL will investigate the variability of dietary supplement composition data attributable to inherent supplement differences, analytical methodology, and other contributing factors. The magnitude of variability attributable to the measurement process will vary for each ingredient or ingredient group (i.e., minerals analyzed by inductively-coupled plasma spectroscopy (ICP)) and can confound the results for variability inherent in a product. In addition, the assessment of individual ingredient variability will be a factor in determining sample sizes for future analytical studies.
In 2010, NDL made research progress in three new studies: 1. Children’s MVMs: analytical data for a representative group of 65 children’s products were evaluated and summarized to determine the relationship between label and analytical values for up to 20 nutrients; 2. Prenatal MVMs: analytical nutrient data were evaluated for 40 retail and 20 direct sales prenatal MVMs; and 3. Omega-3 supplements: over 50 supplements representing the lower market share were chemically analyzed and data were evaluated for omega-3 fatty acid content. For all studies, statistical sampling plans have been developed using national survey data and current market sources to identify representative products and market channels. Up to 6 lots per product were purchased nationwide. Qualified laboratories analyzed nutrient components. Quality control was monitored using validated laboratory methods, reference materials, and duplicate analysis.
In FY2010 NDL collaborated with a specialized laboratory to develop methodology for analysis of vitamin D in dietary supplements. An optimized method was determined to be acceptable after reviewing results for standard reference materials (SRMs), other control materials, and a variety of MVM matrices. Using this method, selected adult MVM products and all products from the children’s and prenatal studies were analyzed. Results are being evaluated. Final data will be statistically analyzed to establish estimates for vitamin D in children’s and prenatal MVMs reported in national surveys.
NDL scientists worked with developers to begin designing a database model for the Dietary Supplement Ingredient System (DSIS), to incorporate system requirements defined by NDL in a needs assessment. The DSIS will facilitate acquisition, evaluation, analysis, and dissemination of dietary supplement data. NDL scientists communicated DSID progress in scientific reports at annual meetings of Experimental Biology, American Dietetic Association, AOAC, and National Nutrient Databank Conference.