Folate status markers are inversely associated with metabolic syndrome in the post-folic acid fortification period in US adults

Background: In the US, the mandatory fortification of cereal products with folic acid in 1998 has dramatically increased the folate status. It is not known if this increased folate status is associated with metabolic syndrome (MetSyn) in the post-folic acid fortification period. Objective: The objective of this study was to investigate the association between folate status and MetSyn in US adults using nationally representative sample surveys. Methods: Data from five cycles of National Health and Nutrition Examination Surveys, 2007-2008, 2011-2012, 2013-2014, 2015-2016, and 2017-2018 were combined into one master analytic database. After excluding data for missing variables, the final study sample consisted of 9458 adults. National Cholesterol Education Program ATP III criteria were used to define the MetSyn. The relation between folate status markers (serum total folate and 5-methyl tetrahydrofolate) and MetSyn was investigated using multivariable logistic regression. Results: The likelihood of having MetSyn in the 4th quartile of serum total folate was significantly lower compared to the 1st quartile (odds ratio, 0.7; 95% CI, 0.57, 0.87 vs 1; P