|Phillips, K - VPI|
|Byrdwell, W Craig|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: July 7, 2008
Publication Date: July 7, 2008
Citation: Patterson, K.K., Exler, J., Lemar, L.E., Holden, J.M., Phillips, K., Harnly, J.M., Byrdwell, W.C., Wolf, W.R. 2008. Optimization of Methodology for Vitamin D3 in Fortified Foods. National Institutes of Health (NIH) Office of Dietary Supplements (ODS) Analytical Methods and Reference Materials Program, Vitamin Methodology Workshop, July 7-8, 2008, Gaithersburg, MD. Technical Abstract: Food composition data for vitamin D in the United States Department of Agriculture’s (USDA) National Nutrient Database for Standard Reference are being updated and expanded as part of the USDA National Food and Nutrient Analysis Program (NFNAP). This program has focused on high priority foods and requires validated analytical methodology and appropriate quality control reference materials in order to achieve accuracy and consistency in new data. Since there are very few certified reference materials for vitamin D, 4 matrix-specific control materials (vitamin D3 fortified - ready-to-eat cereal, orange juice with calcium, fluid milk, and processed cheese) were developed. Six experienced laboratories analyzed each of the control materials in five separate runs to account for run-to-run variability in the results. Additional studies on specific concerns such as recovery and mass spectrometric analysis were done to validate quantification. In one laboratory two AOAC vitamin D methods were combined and adapted to develop a final method that was validated for a variety of food matrices. Results from three laboratories, one using the newly adapted, validated method and the others using their standard methods, were in agreement for the fortified materials once a calibration problem at one laboratory was resolved. From these data, tolerance limits for the control materials were established. It was concluded that an internal standard was necessary to achieve adequate precision, and that an experienced analyst and attention to detail were needed. Overall the methodology is cumbersome, and the procedures are time consuming. This tends to reduce the number of sample analyses that can be made even though more analyses would be desirable. To date, validated methodology has been applied to the analysis of calcium-fortified orange juices and fluid milk. The CV for the control materials was found to be 4 – 5% and the values were within the tolerance limits. The accuracy and precision of sample analyses for these foods will make it possible to determine valid estimates of the vitamin D content.