Technical Abstract: This report briefly reviews existing methods for analyzing the vitamin D content of fortified and non-fortified foods. The existing chemical methods are similar; all are time consuming; require experienced technicians; have only been validated for dairy products or animal feed materials; and have only been validated for vitamin D3, not vitamin D2. 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 analytical methods. Recently, the U.S. Department of Agriculture, as part of a project to update the vitamin D values in the National Nutrient Database of Standard Reference, established an analytical methods committee to compare several existing vitamin D methods and to characterize five control materials (skim milk, processed cheese, cereal, orange juice, and salmon). Initial relative standard deviations (RSDs) for the five materials ranged from 35% to 50%. Elimination of systematic biases related to the methods and the standards yielded much more satisfactory RSDs of 7% to 12%. This research demonstrated that existing methods for analyzing 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 desperately need certified reference materials for foods.