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Dietary Supplement Laboratory Quality Assurance Program (DSQAP)

Summary

The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS), revitalized the Dietary Supplement Laboratory Quality Assurance Program (DSQAP) to support the measurement needs of the dietary supplements community. The DSQAP provides an opportunity for dietary supplements testing laboratories to improve comparability of their measurements, as well as for NIST to assess community needs for reference materials, workshops, and other measurement services.

Description

Montage of photographs showing brewed green tea, filled capsules resting on a ginkgo leaf, seaweed, and ginsing roots, powder, and leaves.
Credit: Canva stock

Approximately 75% of the U.S. population takes dietary supplements, including vitamins and mineral supplements, representing an annual expenditure of more than $20 billion. Regulations, driven by reported cases of inaccurate labeling, adulteration, contamination (with pesticides, heavy metals, or toxic botanicals), and drug interactions, are now in place that require manufacturers to evaluate the identity, purity, and composition of their ingredients and finished products. In 2007, a Dietary Supplement Laboratory Quality Assurance Program (DSQAP) was initiated to enable participants to improve the accuracy and precision of their measurements for nutrients, marker compounds, toxic elements, and/or pesticides in dietary supplement ingredients and finished products. From 2017 to 2021, the participants of the DSQAP were served by studies conducted as part of the Health Assessment Measurements QAP. As part of a revamp of the NIST QAPs in 2021, NIST and ODS revitalized the DSQAP, which conducted its sixteenth exercise in 2022.

Approximately twice a year, exercises offer participants the opportunity to measure concentrations of nutritional and toxic elements, fat- and water-soluble vitamins, fatty acids, active and/or marker compounds, and contaminants in samples distributed by NIST. Participant data is compiled at NIST and analyzed for accuracy, precision, and concordance within the community. Reports and certificates of completion are sent to participants. Workshops and other presentations will offer opportunities to discuss results, measurement challenges, and methodological advancements in the characterization of dietary supplements. The intercomparison exercises, data reports, and workshops are designed to provide participating laboratories with the tools to evaluate their dietary supplement analytical methodology. Information gained through participation may be used by the participants to demonstrate "appropriateness" of analytical methodology to regulatory agencies and to improve the quality of information associated with dietary supplement products through increased measurement capabilities.

Future DSQAP studies may address additional areas such as botanical authenticity, as needs are identified. Please send suggestions for future studies or requests for additional information regarding DSQAP and other NIST QAPs to QAPHUB [at] nist.gov (QAPHUB[at]nist[dot]gov).

Upcoming Exercises

Exercise 3 (In progress – registration closed)

Study

Measurands and Samples

Toxic Elements

As, Cd, Pb, and Hg in kava root and kava extract

Fat-Soluble Vitamins

Total retinol and retinyl acetate in multivitamin tablets

Water-Soluble Vitamins

Thiamin (B1) and riboflavin (B2) in yohimbe containing solid oral dosage form and multivitamin tablets

Botanicals

Kava lactones in kava root and kava extract

Exercise 3 Final Report is in progress.


Exercise 2 (In progress – registration closed)

Study

Measurands and Samples

Toxic ElementsAs, Cd, Pb, and Hg in eleuthero and ginger extracts
Fat-Soluble VitaminsTotal β-carotene in saw palmetto and multivitamin tablets
Botanicals IGingerols in ginger rhizome, extract, and ginger-containing supplements
Fatty AcidsFatty acids in fish oils
Botanicals IITriterpene glycosides in black cohosh rhizome and extract

Crossed out studies were offered but then cancelled due to low enrollment

Exercise 2 Final Report is coming soon.

Major Accomplishments

Exercise 1

Study

Measurands and Samples

Elements*

Ca, Cr, Mg, I, Na, K, As, Cd, Cu, Zn, Se, I, S, and Hg in kelp

Vitamins I*

Niacin and vitamin K1 in kelp

Vitamins II

Vitamins B1, B2, B3, B5, B6, B7, B9, & B12 in liquid and powdered drink mixes

Botanicals I*Phenolic content in kelp and green tea
Botanicals IIWithanolides in ashwagandha

Proximates*

Ash, carbohydrates, fat, protein, solids, starch, total dietary fiber, and calories in kelp

Contaminants*

PFAS in kelp

*Study run in part as a collaboration with World Wildlife Fund (WWF)
Exercise 1 Final Report.

WORKSHOPS

NIST DSQAP Workshop (April 23, 2023): NIST and the University of Mississippi National Center for Products Research co-sponsored a half-day workshop that was held in conjunction with the 21st Oxford International Conference on the Science of Botanicals (ICSB). The workshop described recent updates to NIST QAP offerings, and focused on discussion of the analytical challenges in measuring nutrients, phytochemicals, or contaminants in dietary supplements, botanicals, and other natural products.

Supporting The Standardization of Seaweed Measurements Workshop (October 24, 2023): In support of the DSQAP Exercise 1 seaweed collaboration with World Wildlife Fund (WWF), NIST hosted a workshop to discuss the QAP results, observations, and technical recommendations, as well as provide opportunities for discussions on improving measurement capabilities. The workshop included presentations from both NIST staff and external experts, along with discussions between NIST staff and participants for more in-depth conversations. These discussions with the research and analytical laboratory communities included the importance of robust and validated analytical methods and the future role of NIST in supporting seaweed measurement standardization.

Historical Exercises

Past participants can access historical results at QAP HUB. Log in using your existing credentials, or enter your email address to request a new password.

Exercise A

Study

Measurands and Samples

Nutritional Elements

Ca, Fe, Mg, and Zn in multivitamin tablets

Toxic Elements

Pb in Ginkgo and Ephedra tablets

Water-Soluble Vitamins

Folic acid in multivitamin tablets and infant formula

Fat-Soluble Vitamins

Vitamins A & E in multivitamin tablets and infant formula

Fatty Acids

Fatty acids in vegetable oil blends

Botanicals

Caffeine in solid oral dosage forms

Exercise A Report

Exercise B

Study

Measurands and Samples

Toxic Elements

As in Ephedra

Water-Soluble Vitamins

Vitamins B1 & B2 in multivitamin tablets

Botanicals

Phytosterols in saw palmetto, flavonols in Ginkgo biloba
synephrine in bitter orange

Exercise B Report

Exercise C

Study

Measurands and Samples

Nutritional Elements

Ca, Na, P, and Zn in protein drink mix and fortified milk powder

Toxic Elements

As and Cd in bitter orange

Water-Soluble Vitamins

Niacin and vitamin B6 in protein drink mix and fortified milk powder

Fat-Soluble Vitamins

Retinyl palmitate in fortified milk powder

Fatty Acids

Omega-3 and omega-6 fatty acids in botanical oils

Botanicals

Phytosterols in a neat solution and saw palmetto

Exercise C Report

Exercise D

Study

Measurands and Samples

Toxic Elements

Pb in Ginkgo

Water-Soluble Vitamins

Niacin in fortified milk powder

Fat-Soluble Vitamins

β-carotene in oils

Botanicals

Organic acids in berry extracts

Exercise D Report

Exercise E

Study

Measurands and Samples

Nutritional Elements

Ca, Fe, and Zn in fortified breakfast cereals

Water-Soluble Vitamins

Niacin in fortified breakfast cereals

Fat-Soluble Vitamins

β-carotene in oil and multivitamin tablet

Contaminants

Aflatoxins in peanut products

Botanicals

Catechins in green tea

Exercise E Report

Exercise F

Study

Measurands and Samples

Nutritional Elements

Na and Fe in chocolate, spinach, and blueberries

Toxic Elements

As, Cd, Pb, and Hg in green tea

Water-Soluble Vitamins

Vitamins B1, B3, B6, & B12 in milk powder, blueberries,
and B-vitamin tablets

Fat-Soluble Vitamins

Vitamin D in infant formula and supplements

Fatty Acids

Fatty acids in botanical oils, fish oils, and fish tissue

Botanicals

Isoflavones in soy-containing products

Participants in DSQAP Exercise F can request a copy of the final report via email to QAPHUB [at] nist.gov (QAPHUB[at]nist[dot]gov).

Exercise G

Study

Measurands and Samples

Nutritional Elements

Na in tomato leaves and cranberry powder

Toxic Elements

Pb in multivitamin tablets and Ephedra-containing tablets

Water-Soluble Vitamins

Folate in breakfast cereal and fortified milk powder

Fat-Soluble Vitamins

β-carotene in ethanolic solutions and saw palmetto extract

Botanicals

Anthocyanins/anthocyanidins in cranberry and bilberry extracts

Exercise G Report

Exercise H

Study

Measurands and Samples

Nutritional Elements

Ca, Cu, and Mn in calcium supplement and oyster tissue

Water-Soluble Vitamins

Choline in soy flour and egg powder

Fat-Soluble Vitamins

Tocopherols in carrot oil and egg powder

Fatty Acids

Omega-3 and -6 fatty acids in saw palmetto extract and berries

Contaminants

PAHs in neat solution and green tea leaves

Botanicals

Phytosterols in flax and perilla oils

Exercise H Report

Exercise I

Study

Measurands and Samples

Nutritional Elements

Cr, Mo, and Se in egg powder and multivitamin tablets

Toxic Elements

Cd in breakfast cereal and calcium supplement

Water-Soluble Vitamins

Pantothenic acid soy flour and blueberries

Fat-Soluble Vitamins

Vitamin A in egg powder and breakfast cereal

Botanicals

Catechins in green tea leaves and extract

Exercise I Report

Exercise J

Study

Measurands and Samples

Nutritional Elements

Ca, Mg, and Z in natural and enhanced waters

Toxic Elements

As in St. John's wort

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

Identity

Pure and adulterated Ginkgo biloba.
**Consensus-based only, no quantitative results required

Exercise J Report

Exercise K

Study

Measurands and Samples

Nutritional Elements

P and Fe in cranberry and blueberry

Toxic Elements

Hg in Ephedra and Ginkgo

Water-Soluble Vitamins

Vitamins B1, B2, and B3 in multivitamin tablets and protein powder

Fat-Soluble Vitamins

Vitamin K1 in multivitamin tablets and protein powder

Contaminants

Acrylamide in chocolate and coffee

Botanicals

Phytosterols in saw palmetto

Exercise K Report

Exercise L

Study

Measurands and Samples

Nutritional Elements

Iodine in cat food and multivitamin tablets

Toxic Elements

As and Pb in St. John’s wort

Water-Soluble Vitamins

Biotin in cat food and multivitamin tablets

Fat-Soluble Vitamins

Lutein and zeaxanthin in spinach and multivitamin tablets

Fatty Acids

Omega-3 and -6 in fish oils

Botanicals

Chlorogenic acid, flavonoids, and naphthodianthrones in St. John’s wort

Exercise L Report

Exercise M

Study

Measurands and Samples

Nutritional Elements

K and Zn in spinach and spirulina

Toxic Elements

As and Pb in ginger and ginseng

Water-Soluble Vitamins

Vitamins B1 and B2 in spirulina and multivitamin tablets

Fat-Soluble Vitamins

Vitamin K1 in basil and kelp

Botanicals

Curcuminoids in turmeric

Identity

Chondroitin sulfate

Exercise M Report

Exercise N

Study

Measurands and Samples

Nutritional Elements

Cr in a chromium supplement and multivitamin tablets

Toxic Elements

As, Cd, and Pb in calcium supplement and ginkgo supplement

Water-Soluble Vitamins

Folic acid in cereal and multivitamin tablets

Fat-Soluble Vitamins

vitamin D in protein powder, calcium supplement, and
multivitamin tablets

Fatty Acids

Omega-3 and -6 in saw palmetto berries and botanical oil

Botanicals

Ginsenosides in ginseng

Exercise N Report

Exercise O

Study

Measurands and Samples

Toxic Elements

AS, Cd, Pb, and Hg in black cohosh and turmeric

Natural Products

Curcuminoids in turmeric; Chondroitin sulfate in supplements

Botanicals

Botanical ID: Ginkgo biloba

Exercise O Report

Related Standard Reference Materials

As part of a multi-year interagency agreement among the NIST, the NIH/ODS, the Food and Drug Administration (FDA) Center for Food Safety and Applied Nutrition (CFSAN), and the FDA Center for Drug Evaluation and Research (CDER), NIST is developing Reference Materials (RMs) and Standard Reference Materials (SRMs) for botanical dietary supplements. RMs and SRMs with assigned values for concentrations of active and/or marker compounds, pesticides, and toxic elements are being produced to assist in the verification of manufacturers' label claims and for use in quality control during the manufacturing process in support of the Good Manufacturing Practices released by the FDA in 2007. 

For the most up-to-date information about available RMs and SRMs, visit the NIST Store.

Associated Publications

If you or your institution subscribe to a journal cited below, clicking on the link should take you to a page from which you can access the reference.

Created December 17, 2008, Updated July 9, 2024