Multivitamin/Multielement Dietary Supplement SRM

The Analytical Chemistry Division has produced SRM 3280 Multivitamin/Multielement Tablets for use as a control by laboratories making vitamin or element measurements in similar types of dietary supplements. Certified and reference values are assigned for more than 18 elements and 15 vitamins and carotenoids.  Elements include: boron, calcium, chloride, chromium, copper, iodine, iron, magnesium, manganese, molybdenum, nickel, phosphorous, potassium, selenium, silicon, tin, vanadium, and zinc. The vitamins and carotenoids include: vitamins A, D, E, K, B₁, B₂, B₆, B₁₂, and C, niacin, folic acid, biotin, pantothenic acid, β-carotene, and lutein.

The National Institutes of Health (NIH), Office of Dietary Supplements (ODS) is collaborating with the U.S. Department of Agriculture (USDA) to establish the Dietary Supplement Ingredient Database (DSID). The DSID project will report the results of a systematic survey of supplement composition, including chemical analyses of ingredients and indicators of data quality. The initial focus of the DSID project is on vitamin and mineral supplements. To support the DSID project, the Analytical Chemistry Division (ACD) of the National Institute of Standards and Technology (NIST) and NIH-ODS are collaborating to develop a Standard Reference Material (SRM) for use in validating analytical methods for multivitamin/multielement supplements. Dietary supplement manufacturers will also use this SRM as a control material for quality assurance of measurements to meet labeling claims.

A combination of results from two independent methods employed at NIST, including higher-order methods, as well as results from USDA and European laboratories expert in the measurement of vitamins were used for characterization of this material. The elements were determined at NIST using a combination of several methods including x-ray fluorescence spectrometry (XRF), instrumental neutron activation analysis (INAA), prompt gamma activation analysis (PGAA), and inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) to provide measurements by at least two methods for each element. XRF was used to assess the homogeneity of the SRM for most of the elements. The vitamins and carotenoids were measured at NIST using two independent analytical methods (where feasible) based on liquid chromatography (LC) with UV/visible absorbance or fluorescence detection, LC with mass spectrometric detection (LC/MS), and/or LC with tandem mass spectrometry (LC/MS/MS). Where possible, stable isotope-labeled vitamins were used as internal standards. This approach often results in more rigorous methods that are less susceptible to biases from matrix interferences, analyte instability, and extraction/processing losses. The SRM’s homogeneity with respect to the vitamins was assessed using these methods. For both the vitamin/carotenoid and element determinations, samples of the SRM were distributed to other laboratories (e.g., USDA, Grocery Manufacturers Association, European Committee for Standardization (CEN)) to provide additional results to assist in the value assignment of the SRM. 

Major Accomplishments:

• SRM 3280 Multivitamin/Multielement Tablets has been characterized for more than 18 elements and 15 vitamins and carotenoids.   
• Isotope dilution LC/MS and LC/MS/MS methods of analysis have been developed for determination of vitamins.

To view the Certificate of Analysis for this material, click here.