Location: Nutrient Data Laboratory2015 Annual Report
1a. Objectives (from AD-416):
The Dietary Supplement Ingredient Database (DSID) (http://dsid.usda.nih.gov; (U.S. Department of Agriculture, 2012) currently provides nationally representative supplement composition data for adult and children’s MVM, based on chemical analysis. All other dietary supplement databases contain label information only. In addition to the evaluation of vitamin and mineral levels in dietary supplements, the DSID will be expanded to include supplements with other ingredients of interest, including omega-3 (n-3) fatty acids in fish and plant oil supplements, and catechins, caffeine, and flavonoids in botanical supplements. Objective 1: Determine, evaluate, and expand knowledge about the composition of frequently consumed dietary supplements in the U.S. by collecting and compiling data and information on essential nutrients and emerging components of public health importance. This includes developing methods for sampling new dietary supplement product types, statistically evaluating analytical results to portray representative estimates, and improving the value of the Dietary Supplement Ingredient Database by utilizing new technologies to generate novel datasets.
1b. Approach (from AD-416):
Several types of studies are planned, including ongoing national and monitoring studies and new pilot and national studies. NDL will design and carry out research to analytically determine the ingredient composition of representative dietary supplements, including essential nutrients and bioactive components. NDL will identify laboratories for sample analysis and evaluate data quality. Results will be statistically evaluated and made publicly available through the DSID. On-going DSID Studies: 1) Omega-3 fatty acid national study: scientifically evaluate the relationships between labeled and analytical levels of omega-3 fatty acids in representative dietary supplements, including fish oil, plant oil and fish/plant oil blends. Release mean results and variability information from this study in DSID-3. 2) Over-the-Counter (OTC) prenatal MVM national study: scientifically evaluate the relationship between label and analytical values and assess the variability for up to 22 vitamins and minerals in OTC prenatal MVM. Release mean results and variability information from this study in DSID-3. 3) Adult MVM monitoring study: systematically evaluate the statistical relationships between label and analytical data since the first adult MVM study in a monitoring study of adult MVM, and release results in DSID-4. The information from this study will be used to plan the frequency and scope of updates to DSID for other MVM and possibly other supplement categories. Pilot Studies: 1) Green tea study AND flavonoid-containing dietary supplements (DS) study: methods of analysis will be evaluated by testing representative and top-selling products for prioritized ingredients of interest. 2) Calcium in DS and OTC antacids study: DS and OTC antacids, a major source of supplemental calcium intake in the U.S., will be assessed for their calcium and vitamin D content. National Studies: 1) Green tea DS and flavonoid-containing DS studies: obtain mean estimates for and measures of variability for analyzed catechins, caffeine, and for analyzed flavonoids (such as flavonols, flavones, flavanones, catechins, and anthocyanidins) in nationally representative botanical DS. 2) Calcium in DS and OTC antacids study: determine national estimates for ingredients in calcium-containing DS, a commonly reported supplement
3. Progress Report:
Objective 1: Determine, evaluate, and expand knowledge about the composition of frequently consumed dietary supplements in the U.S. by collecting and compiling data and information on essential nutrients and emerging components of public health importance. Catechins and caffeine in green tea (GT) dietary supplements: NDL is conducting a GT pilot study. Two lots of 32 dietary supplements containing primarily or only GT were analyzed for the major phytochemicals in green tea, including individual catechins (especially epigallocatechin gallate: EGCG), caffeine, theobromine and theonine. Product retests are now complete. Three laboratories participated in this pilot study: Food Composition and Methods Development Lab at USDA (FCMDL), and 2 commercial laboratories. Results for several National Institute of Standards and Technology (NIST) GT standard reference materials (SRM) confirmed that the selected labs met quality control specifications for accuracy and precision. Final statistical analysis is underway. A preliminary analysis of these data indicated a wide range of analytical levels for the catechins and caffeine. Results were compared to voluntary label claims for EGCG or caffeine amounts (n=18 and 8, respectively). While most EGCG analytical values were within 20% of label claims, analytical results for caffeine were less consistent with label claims (ranged from -83 to +62% from label) on a per gram basis. For dietary supplements, disintegration is the ability of a tablet or capsule to break apart within a specified amount of time after being ingested, so that the ingredients become available to the body. The GT supplements were tested for disintegration and the initial pass rate was 58.6% (17 of 29 products). Selected GT DS products are also undergoing dissolution testing, which measures compounds released from DS in a system mimicking stomach conditions. EGCG has been selected as the marker compound of interest for dissolution tests. In order to verify and optimize the botanical DS testing protocols for the DSID studies, NDL is consulting with scientists at the Food and Drug Administration (FDA) and United States Pharmacopeia (USP) who are experts in this field. DSID-3 released on March 26 2015: In release 3.0, results for the analytically-derived estimates of ingredient content for non-prescription prenatal MVMs and omega-3 fatty acids supplements are published for the first time. The new DSID results are linked to NHANES data files for these product categories. For the non-prescription prenatal MVM, the new data are built into an online calculator. In addition, updated calculators and NHANES linking tables are provided for expanded adult and children’s MVM data. The DSID-3 release includes updated and new research summaries for 4 national studies and numerous improvements in web page content and design. Predicted analytical amounts for eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and/or alpha-linolenic acid (ALA) in omega-3 fatty acid DS are reported in DSID-3. All of these data are appropriate for use in population studies of nutrient intake rather than for assessing individual products. Adult MVM 2 study: The purpose of this study is to monitor changes in the statistical relationships between label and analytical data since the first adult MVM study (begun in 2006). In addition, new ingredients will be added to the DSID for this product category. Adult MVM are the most commonly reported dietary supplement category in the US. Vitamins A and D, iodine, and chromium are a particular focus in this study due to ODS/public health interest and major improvements in analytical methodology for these ingredients. The laboratory results and identified retests for multiple lots of 124 supplements purchased from multiple channels have been reviewed. Results for individual lots of products were compared to each other and to labeled levels. The final data review is complete and statistical analysis has begun. The results from this study will be reported in DSID-4. Measurement of vitamin D and 25(OH)D in foods and dietary supplements: Although this study was not originally planned for this 5 year cycle, there is a great deal of interest in the levels of vitamin D and 25(OH)D in foods and dietary supplements. This study falls within the objectives of the DSID project to “determine, evaluate, and expand knowledge about the composition of frequently consumed dietary supplements” and was funded by the Office of Dietary Supplements (ODS). In this discussion, use of the general terms, vitamin D and 25(OH)D refers to both the D2 and D3 forms. Health effects of the vitamin D metabolite, 25(OH)D, may be more potent than non-metabolized vitamin D. However, reliable sources for the analytically estimated 25(OH)D content in foods and DS are very limited or nonexistent. An 18-month Interagency Agreement between ARS and ODS set up a pilot study to measure vitamin D2 , vitamin D3 , 25(OH)D2 and 25(OH)D3 in foods and DS. The goal was to estimate the variability among both domestic and international labs in measuring 25(OH)D content reported for varied foods and matrices. In addition, the outcome of the trial may help NIST to formulate SRMs necessary for the harmonization of 25(OH)D methods and reporting protocols. After assessing vitamin D3 and 25(OH)D3 in six vitamin D products claiming vitamin D3 content, one DS labeled at 2000 IU was chosen for this study. This DS was analyzed for vitamin D3 and 25(OH)D3 by three laboratories. One laboratory analyzed the DS for vitamin D2 and 25(OH)D2 and the results indicated that these components are not present or are below detection limits. The mean analytical value for vitamin D3 was 24,600 mcg/100 g (28.4% above label) and all three laboratories were in relatively good agreement with each other (relative standard deviation (RSD)= 12.7%). The 3 laboratories differed in their results for 25(OH)D3 with values ranging from 0.26 - 1.2 mcg/100g (mean = 0.82 mcg/100g; RSD = 44.4%). Additional research is needed to determine the best method for analyzing the levels of 25(OH)D in vitamin D supplements. The DSID team worked with NDL food specialists on the final report for the 25(OH)D pilot study and now is working on the related manuscript.
1. The Dietary Supplement Ingredient Database (DSID)-3 (http://dsid.usda.nih.gov) was released in March 2015 by ARS scientists in the Beltsville Human Nutrition Research Center, Beltsville, Maryland, with new national estimates of ingredient levels in non-prescription prenatal multivitamin/minerals (MVM) and omega-3 fatty acid products, and updated vitamin and mineral estimates in children’s and adult MVM. Ingredient information in the DSID can be used to improve precision for nutrient intake estimates contributed by dietary supplements. These estimates can then be combined with ingredient intakes from foods obtained from the USDA food composition database, to better evaluate total dietary intake.
Saldanha, L.G., Dwyer, J.T., Andrews, K.W., Betz, J.M., Harnly, J.M., Pehrsson, P.R., Rimmer, C.A., Savarala, S. 2015. Feasibility of including green tea products for an analytically verified dietary supplement database. Journal of Food Science. DOI: 10.1111:1750-3841.12838.