Monitoring Analytical Ingredient Content in Adult Multivitamin/Mineral Products (MVM) for the Dietary Supplement Ingredient Database (DSID)
Authors: Gusev Pavel A , Andrews Karen W , Dang PhuongTan , Han Fei , Savarala Sushma , Pehrsson Pamela R , Dwyer Johanna T , Betz Joseph M , Saldanha Leila G , Costello Rebecca B , Douglass Larry W 
Published: November 2023

Dietary supplement (DS) consumption plays an important role in achieving recommended nutrient levels for a large part of the U.S. population, and MVM are the most commonly consumed DS. Knowledge of DS composition based on chemical analysis rather than label declarations has become critical for more complete dietary intake assessment and for deciphering its associations with disease risk and health in epidemiological studies. To better assess nutrient intake from DS, the Nutrient Data Laboratory at the U.S. Department of Agriculture and the Office of Dietary Supplements at the National Institutes of Health, in collaboration with other federal agencies, built and maintain the DSID that provides analytically‐derived estimates of ingredient content in DS at the national level.

Release 3 of the DSID (http://dsid.usda.nih.gov) reports analytical estimates in adult, children's and non‐prescription prenatal MVM. Relationships between the analytical and labeled content in nationally representative DS samples are evaluated by regression analysis weighted by DS market share. The regression equations are incorporated into DSID online calculators that convert label ingredient amount into predicted analytical content. DSID‐3 calculators for adult MVM are based on adult MVM purchased in 2006–07 as part of a sampling plan incorporating information from the National Health and Nutrition Examination Surveys (NHANES) 2001–02 and 2003–04 data and additional DS use and sales surveys for 2006.

The goal of this study is to monitor relationships between the labeled and analytical ingredient content over time. Major improvements in analytical methodology for iodine and chromium and vitamins A and D provide reliable data for these ingredients in adult MVM for the first time. Representative adult MVM were identified using weighted frequency data from the NHANES 2007–08, a 2010 DS use survey by an independent marketing firm, and 2010 market share information from the DS industry. To attain geographically diverse sample sources across different market channels and to combine highly precise estimates of mean content with reliable assessments of product and lot variability, a statistical plan was developed for DS purchase. Using the statistical sampling plan, 124 products were purchased in 2011, with 64 (three lots each) from mass market, 30 (three lots each) from natural health and 30 (two lots each) from direct channels. Product samples were sent to qualified laboratories with quality control materials for the analysis of 22 vitamins and minerals. Initial 1181 test results from 71 batch were evaluated and >500 retest samples were analyzed. Results were finalized and are being statistically evaluated to be released in DSID‐4, along with data links to NHANES DS files. The regression models for both minerals and vitamins will be compared between the original study (DSID‐3) and current analytical values for adult MVM in the monitoring study. The information obtained will be used to plan the frequency and scope of updates to the DSID for other MVM and possibly other DS categories.

Support or Funding Information

Funding: ARS/USDA & ODS/NIH Y1CN501006