| Title | Analyzing vitamin D in foods and supplements: methodologic challenges. | | Author(s) | Byrdwell WC, Devries J, Exler J, Harnly JM, Holden JM, Holick MF, Hollis BW, Horst RL, Lada M, Lemar LE, Patterson KY, Philips KM, Tarrago-Trani MT, Wolf WR | | Institution | Food Composition and Methods Development Laboratory, Beltsville Human Nutrition Research Center, Agriculture Research Service, US Department of Agriculture, Beltsville, USA. | | Source | Am J Clin Nutr 2008 Aug; 88(2):554S-557S. | | Abstract | This report briefly reviews existing methods for analyzing the vitamin D content of fortified and unfortified foods. The existing chemical methods are similar; all are time consuming, require experienced technicians, and have only been validated for a few materials (eg, dairy products or animal feed materials). This report also describes the lack of standard reference materials with certified values for vitamin D that laboratories need to guarantee the accuracy of existing analytic methods. Recently, the US Department of Agriculture, as part of a project to update the vitamin D values in the National Nutrient Database of Standard Reference, established an analytic methods committee to compare several existing vitamin D methods and to characterize 5 control materials (skim milk, processed cheese, cereal, orange juice, and salmon). Initial relative SDs for the 5 materials ranged from 35% to 50%. Elimination of systematic biases related to the methods and the standards yielded much more satisfactory relative SDs of 7% to 12%. This research has shown that existing methods for analyzing the vitamin D content in foods can produce accurate results. A new, simpler, and faster method, however, would greatly benefit the field. To guarantee accuracy, we need certified reference materials for foods. | | Language | eng | | Pub Type(s) | Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
| | PubMed ID | 18689401 |
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