Opportunities to Fill Gaps in Reference Methods for Vitamins in Foods and Dietary Supplements

BACKGROUND: A recent review concluded that most current international reference methods to accurately determine vitamin content in foods and food supplements are no longer fit for purpose. Most reference methods originate from the 1990s and science, technology, and statutory regulations have changed considerably since. OBJECTIVE: AOAC INTERNATIONAL hosted a symposium during its annual meeting in Baltimore in August 2024 to highlight and discuss method gaps and share cutting-edge technology/methods for future consideration as reference methods for vitamins in foods and dietary supplements. METHODS: Five invited speakers discussed gaps, opportunities, and priorities when it comes to future reference method needs in the area of vitamins in foods and dietary supplements. RESULTS: Speakers successively advocated for the following: (1) Harmonization of analytical methods, which is closely related to the harmonization of definitions on what compounds to include and the expression of results with a focus on retinol and retinyl esters as an example. (2) At present there is no way to verify or validate the type of vitamin E on nutrition labels. To express the amount of bioactive vitamin E, chiral analysis is needed to differentiate the type of vitamin E between natural and synthetic. (3) With the objective to develop a cost- and time-efficient method that is accurate and able to quantify all B-vitamins, an LC-ESI-MS/MS method for the simultaneous determination of six B-vitamins, B1, B2, B3, B5, B6, and B7, in foods was presented as a potential new reference method. (4) Attention was requested for the different types of ingredient manufacturing processes, which can cause significant challenges for accurate and precise testing of vitamins. CONCLUSION: Opportunities discussed gave a good perspective of future priorities to be considered when establishing new reference methods for the determination of vitamins in foods and dietary supplements. HIGHLIGHTS: Current method gaps and cutting-edge technology/methods are discussed for future consideration when establishing new reference methods for vitamins in foods and dietary supplements.