2012 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 2012, NDL published the second release of the DSID (DSID-2), with 3 times the content of DSID-1. This release provides estimated levels of 20 vitamin and mineral ingredients derived from analytical results for 64 representative children’s multivitamin/mineral (MVM) supplements. Estimates for ingredients in adult MVMs have been updated. The release also includes DSID codes linked to National Health and Nutrition Examination Survey (NHANES) dietary supplement data and 3 MVM calculators that can be used to apply the regression results to additional ingredient levels for each product category.
Studies are underway analyzing ingredients in over-the-counter prenatal MVMs, omega-3 fatty acid supplements and an adult MVM-2 study. Statistical sampling plans were developed for all studies, identifying market channel distributions and representative products. An average of 3 lots per product was purchased nationwide. Supplements were sent to qualified laboratories and analyzed using validated methods.
Analytical laboratory data for vitamins and minerals in 71 prenatal MVMs were assessed. NDL identified ingredients in specific products for analytical re-testing and those results are currently being evaluated.
Initial statistical analysis of analytical data results identified the need for additional analytical re-tests. The optimum definition of total omega-3 fatty acids for use in the DSID is being considered.
Representative samples purchased in 2011 were sent to laboratories for the analysis of vitamins and minerals. Vitamin D, vitamin A, and chromium are the focus of this study because results for these ingredients were not finalized for the first adult MVM study due to analytical methodology concerns.
To begin the modular approach for the Dietary Supplement Ingredient System (DSIS), the Access databases for each study were upgraded and optimized with structured form and report functions added. Each database documents the product information, analytical testing information and testing results for a study.
NDL scientists reported the DSID-2 release and other DSID research topics in talks at the following meetings: Experimental Biology, National Nutrient Database Conference, Institute of Food Technologists National Meeting and the Covance Food and Dietary Supplement Symposium.
Swanson, C.A., Zimmerman, M.B., Skeaff, S., Pearce, E., Dwyer, J.T., Trumbo, P.R., Zehaluk, C., Andrews, K.W., Carriquiry, A., Caldwell, K.L., Egan, S.K., Long, S.E., Bailey, R.L., Sullivan, K.M., Holden, J.M., Betz, J.M., Phinney, K.W., Brooks, S.P., Johnson, C.L., Haggans, C.J. 2012. NIH workshop summary: shaping the development of an iodine research initiative for the U.S. Journal of Nutrition. DOI: 10.3945/jn.111.156448.
Andrews, K., Roseland, J.M., Holden, J.M., Middleton, A., Solomon, A., Palachuvattil, J., Dwyer, J., Coates, P., Saldanha, L., Bailey, R. 2012. USDA dietary supplement ingredient database, release 2. Available: www.dietarysupplementdatabase.usda.nih.gov.
Saldanha, L.G., Dwyer, J.T., Holden, J.M., Ireland, J.D., Andrews, K.W., Bailey, R., Gahche, J.J., Hardy, C., Moller, A., Pilch, S.M., Roseland, J.M. 2011. A structured vocabulary for indexing dietary supplements in databases in the United States. Journal of Food Composition and Analysis. 25(2):226-33.