FOLATE DEFICIENCY
Measures and criteria used to define biochemical variables of the study
population
Variable
Indicator
Population or Individual*
Folate
deficiency
Serum or plasma
folate
<3 ng/mL (microbiological assay)†
Folate
deficiency
Red blood cell folate
<140 ng/mL (microbiological assay) †
*Senti FR, Pilch SM. Analysis of the folate nutritional status of the U.S. population based
on data collected in the Second National Health and Nutrition Examination Survey,
1976–1980. Bethesda (MD): Federation of American Societies for Experimental Biology;
1984.
†
Due to lack of assay standardization, cut-off values may have to be adjusted depending
on the assay used; 2 ng/mL for serum folate and 95 ng/mL for RBC folate were adjusted
cut-off values used for the BioRad Quantaphase II assay. The BioRad Quantaphase II
assay cut-offs will average approximately 30% less than cut-off values for the
microbiological assay.