Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Micronutrients Measurement Quality Assurance Program (MMQAP)


The Micronutrients Measurement Quality Assurance Program (MMQAP) was initiated in 1984 by the National Cancer Institute Division of Cancer Prevention and Control to ensure the long-term reliability of the measurements made while studying the possible cancer chemoprevention roles of these compounds. Coordinated by the Chemical Sciences Division, MMQAP supported measurement technology for selected fat- and water-soluble vitamins and carotenoids in human serum and provided participants with measurement comparability assessment through use of interlaboratory comparison studies, Standard Reference Materials and control materials, and methods development and validation. The MMQAP concluded in 2017, and parts of the MMQAP community will now be served through the ClinQAP.


The MMQAP supported the long-term (months to years) reliability of selected fat- or water-soluble vitamin measurements in human serum and plasma. Results from the comparison studies helped participants to make accurate clinical and health-care decisions as well as to maintain and improve their measurement comparability.

Major Accomplishments

The MMQAP administered over 90 interlaboratory comparison exercises for the measurement of selected fat- and water-soluble vitamins in human serum and plasma. The comparability of laboratory measurements for target analytes improved substantially over time through the development and promulgation of robust measurement technologies, identification and production of suitable reference materials, isolation and identification of measurement system biases, and support and encouragement of long-term within-laboratory measurement quality control efforts. The average estimated coefficient of variation for retinol and α-tocopherol has been approximately 5% and about 10% for β-carotene since 2000.

Stacked graphical plots showing concordance and apparent precision for various clinical analytes plotted as a function of years over the interval 1985 to 2018.
Evaluation of historic data acquired from quality assurance exercises can provide indications of changes in community measurement performance over time. 
Credit: NIST

Each of the various curves represents the concordance or apparent precision metric transformed into a coefficient of variation (CV) expressed as percentage. The interval marked “Ctrl A-D” represents the period during which control samples A through D were provided to participants to enable validation of their measurement processes before they analyzed the unknown samples.

Study Reports

Reports for intercomparisons from 1988 onward are available as NIST Interagency/Internal Reports (IRs):

1986 7880-38   2002 7880-21 and 7880-20
1987 7880-37   2003 7880-19 and 7880-18
1988 7880-36   2004 7880-17 and 7880-16
1989 7880-35   2005 7880-15 and 7880-14
1990 7880-34   2006 7880-13 and 7880-12
1991 7880-33   2007 7880-11 and 7880-10
1992 7880-32   2008 7880-9 and 7880-8
1993 7880-31   2009 7880-7 and 7880-6
1994 7880-30   2010 7880-5 and 7880-4 
1995 7880-29   2011 7880-3 and 7880-2
1996 7880-28   2012 7880 and 7880-1
1997 7880-27 and 7880-40   2013 7880-41 and 7880-42
1998 7880-26   2014 7880-43 and 7880-44
1999 7880-25   2015 7880-45 and 7880-46
2000 7880-24   2016 7880-40 and 7880-47
2001 7880-23 and 7880-22   2017 7880-48

Related Standard Reference Materials

SRM 968f Fat-Soluble Vitamins in Frozen Human Serum
SRM 968f  Fat-Soluble Vitamins in Frozen Human Serum 
Credit: NIST

SRM 968f Fat-Soluble Vitamins in Frozen Human Serum is intended for use in validating methods for determining fat-soluble vitamins in human serum and plasma and qualifying control materials produced in-house and analyzed using those methods.  This SRM may be purchased from the Office of Reference Materials at NIST.

Additional Technical Details

Serum-based samples with assigned values for target analytes (e.g., retinol, tocopherols, and βcarotene) and performance-evaluation standards were distributed by NIST to participants for analysis. NIST staff provided participants with technical feedback concerning their measurement performance and suggestions for methods development and refinement. A certificate of participation in the QAP was issued at the end of each calendar year.


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 31, 2008, Updated October 20, 2023