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Dietary Supplement Laboratory Quality Assurance Program Information

The National Institute of Standards and Technology (NIST) has established a Dietary Supplement Laboratory Quality Assurance Program (DSQAP) in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS). Participants measure concentrations of active and/or marker compounds and nutritional and toxic elements in samples distributed by NIST. (Participants choose the studies in which they will participate before samples are distributed.) Data are compiled at NIST where they are assessed for accuracy, precision, and concordance within the community. Reports and certificates of participation are sent to participants, and workshops are held to discuss results as well as methodological advancements in the characterization of dietary supplements.

Current Exercise (J)

  • Nutritional elements: Calcium, magnesium, and zinc in natural and enhanced waters
  • Toxic elements: Arsenic in St. John's wort extract and aerial parts
  • Water-soluble vitamins: Vitamins B1, B3, and B6 in multivitamin tablets and enhanced water
  • Fat-soluble vitamins: Vitamin E in multivitamin tablets and enhanced water
  • Fatty acids: Omega-3 and -6 fatty acids in plant and fish oils
  • Contaminants: Aflatoxins in peanut products
  • Botanicals: Isoflavones in soy protein isolate and soy flour
  • Botanical ID: Various samples of pure and adulterated Ginkgo biloba. The results of this study will be consensus-based only, with no quantitative results required.

undefinedOn-line registration is now available at


Studies Included in Previous Exercises:

Exercise A

  • calcium, iron, magnesium, zinc, folic acid, and vitamins A and E in multivitamin/multimineral tablets and infant formula
  • caffeine in solid oral dosage forms
  • fatty acids in oil blends
  • lead in solid oral dosage forms

Exercise B

  • phytosterols in saw palmetto
  • flavonols in Ginkgo biloba
  • synephrine in bitter orange
  • arsenic in ephedra
  • vitamin B1 and vitamin B2 in multivitamin/multielement tablets

Exercise C

  • omega-3 and omega-6 fatty acids in oil blends
  • niacin and vitamin B6 in protein drink mix and fortified milk powder
  • retinyl palmitate in fortified milk powder
  • phytosterols (campesterol, stigmasterol, and ß-sitosterol) in a neat solution, saw palmetto extract, and saw palmetto "berry" powder
  • arsenic and cadmium in bitter orange fruit and extract
  • calcium, sodium, phosphorous, and zinc in protein drink mix and fortified milk powder

Exercise D

  • niacin (as niacinamide) in fortified milk powder
  • ß-carotene in oils
  • organic acids in berry extracts
  • lead in ginkgo

Exercise E

  • nutrition elements and niacin in fortified breakfast cereal
  • aflatoxins in peanut products
  • catechins in green tea
  • β-carotene in oil and multivitamin tablet

Exercise F

  • sodium and iron in chocolate, spinach, and blueberry-containing products
  • toxic elements in green tea products
  • water-soluble vitamins in infant formula, milk powder, blueberries, and B-vitamin tablets
  • vitamin B12 in vitamin tablets
  • vitamin D in infant formula and supplements
  • fatty acids in botanical oils, fish oils, and fish tissue
  • isoflavones in soy-containing products.

Exercise G

  • Sodium in tomato leaves and cranberry powder
  • Lead in multivitamin tablets and ephedra-containing tablets
  • Beta-carotene in ethanolic solutions and saw palmetto extract
  • Folate in breakfast cereal and fortified milk powder
  • Anthocyanins/anthocyanidins in cranberry and bilberry extracts.

Exercise H 

  • Phytosterols in flax and perilla oils
  • Omega-3 and -6 fatty acids in saw palmetto extract and berries
  • Tocopherols in 'carrot oil' and egg powder
  • Choline in soy flour and egg powder
  • PAHs in neat solution and green tea leaves
  • Ca, Cu, and Mn in calcium supplement and oyster tissue

Exercise I

  • Catechins in green tea leaves and extract
  • Vitamin A in egg powder and breakfast cereal
  • Pantothenic acid soy flour and blueberries
  • Cadmium breakfast cereal and calcium supplement
  • Chromium, molybdenum, and selenium in egg powder and multivitamin tablets

 Examples of summary tables and individualized data provided to participants are linked below. A Certificate of Participation and a plot of data obtained in one study are provided below.

CONFIDENTIALITY STATEMENT: It is our policy that participants' laboratory identification numbers remain confidential and known only to them and ourselves.

Exercise A Report
Exercise B Report
Exercise C Report
Exercise D Report
Exercise E Report
Exercise H Report
Exercise I Report


A partial list of participants in the DSQAP is provided below. Inclusion of a laboratory here does not imply recommendation or endorsement by NIST.

Adam Nutrition, Mira Loma, CA
Alacer Corporation, Foothill Ranch, CA
Alkemists Laboratories, Costa Mesa, CA
ALS Laboratory Group, Salt Lake City, UT
Analytical Food Laboratories, Grand Prairie, TX
BCIT, Burnaby, BC
BI Nutraceuticals, Long Beach, CA
Cawthron Institute, Nelson, New Zealand
Chromadex, Inc., Boulder, CO
Covance Laboratories, Inc., Madison, WI
Craft Technologies, Inc., Wilson, NC
Dionex Corporation, Sunnyvale, CA
Eurofins Steins Laboratorium, Veden, Denmark
Exova Inc., Santa Fe Springs, CA
FCMDL U.S. Dept. of Agriculture, Beltsville, MD
Food and Drug Administration, Atlanta, GA
Food and Drug Administration, Jamaica, NY
Genysis Nutritional Labs, Salt Lake City, UT
Health Canada, Longueuil, Quebec
Health Canada, Scarborough, Ontario
Health Canada Toronto Inspectorate Lab, Toronto, Ontario
Industrial laboratories, Wheatridge, CO
Medallion Laboratories, Minneapolis, MN
Natural Factors Nutritional Products Inc., Coquitlam, BC
Nature's Way, Springville, UT
Nestle, Vers Chez les Blanc, Switzerland
Nestle Quality Assurance Laboratory, Dublin, OH
NOW Foods, Bloomingdale, IL
NSF International, Ann Arbor, MI
Nutra Manufacturing, Greenville, SC
Nutraceutical Corp., Ogden, UT
Nutrilite, Buena Park, CA
Pharmanex, Provo, UT
Pickering Laboratories, Inc, Mountain View, CA
Research and Productivity Council, Fredericton, NB
Schwabe North America, Green Bay, WI
Shaklee Corporation, Hayward, CA
Silliker JR Labs, Burnaby, BC
Standard Process, Inc., Palmyra, WI
University of Hertfordshire School of Pharmacy, Hatfield, UK
Vitatech International, Tustin, CA
West Chester University, West Chester, PA

DSQAP Workshop

Workshops are held for participants in the QA program. These workshops provide an opportunity for participants to discuss analytical methods, results of the intercomparison exercises, and other related topics.

How to Join the Program

If you are interested in joining our program, please send an e-mail to There is no fee for participation, nor are participants paid.

Photo credit:  Lane Sander, NIST

Catherine A. Rimmer
Phone 301-975-3651

Melissa M. Phillips
Phone 301-975-4134 

Laura J. Wood
Phone 301-975-4111