The Micronutrients Measurement Quality Assurance Program was coordinated by the Chemical Sciences Division and supported measurement technology for selected fat- and water-soluble vitamins and carotenoids in human serum. This program 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. This program 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 HAMQAP.
NIST Micronutrients Measurement Quality Assurance (QA) 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.
The Micronutrients Measurement QA Program at NIST 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.
Reports for intercomparisons from 1988 onward are available:
Serum-based samples with assigned values for target analytes (e.g., retinol, tocopherols, and β-carotene) 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 QA program was issued at the end of each calendar year.