DESCRIPTION
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 manufactures to evaluate the identity, purity, and composition of their ingredients and finished products. In 2007 a Dietary Supplements 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. Approximately two intercomparison exercises are planned each year, with five to seven sample sets distributed in each exercise. Samples prepared and distributed by NIST are commercial samples with values assigned by NIST, or Standard Reference Materials available from NIST.
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.
On-line registration is now available athttps://qa.nist.gov/dsqap/
Studies Included in Previous Exercises:
Exercise A
- Nutritional elements: calcium, iron, magnesium, and zinc in multivitamin tablets
- Toxic elements: lead in Ginkgo and Ephedra tablets
- Water-soluble vitamins: folic acid in multivitamin tablets and infant formula
- Fat-soluble vitamins: vitamins A and E in multivitamin tablets and infant formula
- Fatty acids: fatty acids in vegetable oil blends
- Contaminants: none
- Botanical marker compounds: caffeine in solid oral dosage forms
Exercise B
- Nutritional elements: none
- Toxic elements: arsenic in Ephedra
- Water-soluble vitamins: vitamins B1 and B2 in multivitamin tablets
- Fat-soluble vitamins: none
- Fatty acids: none
- Contaminants: none
- Botanical marker compounds: phytosterols in saw palmetto, flavonols in Ginkgo biloba synephrine in bitter orange
Exercise C
- Nutritional elements: calcium, sodium, phosphorous, and zinc in protein drink mix and fortified milk powder
- Toxic elements: arsenic and cadmium 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
- Contaminants: none
- Botanical marker compounds: phytosterols in a neat solution and saw palmetto
Exercise D
- Nutritional elements: none
- Toxic elements: lead in Ginkgo
- Water-soluble vitamins: niacin in fortified milk powder
- Fat-soluble vitamins: β-carotene in oils
- Fatty acids: none
- Contaminants: none
- Botanical marker compounds: organic acids in berry extracts
Exercise E
- Nutritional elements: calcium, iron, and zinc in fortified breakfast cereals
- Toxic elements: none
- Water-soluble vitamins: niacin in fortified breakfast cereal
- Fat-soluble vitamins: β-carotene in oil and multivitamin tablet
- Fatty acids: none
- Contaminants: aflatoxins in peanut products
- Botanical marker compounds: catechins in green tea
Exercise F
- Nutritional elements: sodium and iron in chocolate, spinach, and blueberries
- Toxic elements: arsenic, cadmium, lead, and mercury in green tea
- Water-soluble vitamins: vitamins B1, B3, B6, and BB12 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
- Contaminants: none
- Botanical marker compounds: isoflavones in soy-containing products
Exercise G
- Nutritional elements: Sodium in tomato leaves and cranberry powder
- Toxic elements: lead 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
- Fatty acids: none
- Contaminants: none
- Botanical marker compounds: anthocyanins/anthocyanidins in cranberry and bilberry extracts
Exercise H
- Nutritional elements: calcium, copper, and manganese in calcium supplement and oyster tissue
- Toxic elements: none
- 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
- Botanical marker compounds: phytosterols in flax and perilla oils
Exercise I
- Nutritional elements: chromium, molybdenum, and selenium in egg powder and multivitamin tablets
- Toxic elements: cadmium 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
- Fatty acids: none
- Contaminants: none
- Botanical marker compounds: catechins in green tea leaves and extract
Exercise J
- Nutritional elements: Calcium, magnesium, and zinc in natural and enhanced waters
- Toxic elements: arsenic 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
- Botanical marker compounds: isoflavones in soy protein isolate and soy flour
- Botanical ID: pure and adulterated Ginkgo biloba. **Consensus-based only, no quantitative results required
Exercise K
- Nutritional elements: phosphorus and iron in cranberry and blueberry
- Toxic elements: mercury 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
- Fatty acids: none
- Contaminants: acrylamide in chocolate and coffee
- Botanical marker compounds: phytosterols in saw palmetto
- Botanical ID: none
Examples of reports distributed to participants 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
- Exercise J Report
- Exercise K Report
Contact:
If you are interested in joining our program, please send an e-mail to dsqap@nist.gov.