AbstractFolate status assessments depend primarily on the measurement of biomarkers such as serum and red blood cell folate. Lessons learned from a large national monitoring system such as the National Health and Nutrition Examination Survey and a public health intervention such as the implementation of folic acid fortification in the United States have provided useful insights into the challenges of assessing folate status and possible solutions for addressing these challenges. © 2011 International Union of Biochemistry and Molecular Biology, Inc. 2011