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Background/Aim: Inadequate folate during pregnancy has been associated with congenital birth deficits and adverse neurodevelopmental outcomes, including autism spectrum disorders. Recent studies show that folic acid supplementation may protect against the potential adverse effects of gestational chemical exposures on neurodevelopment. However, it is unclear whether these chemicals impact folate metabolism. Therefore, we investigated the relationship between environmental chemicals and red blood cell (RBC) folate concentrations.Methods: We assessed associations of 41 chemical biomarkers including metals, phthalate metabolites, per- and polyfluroalkyl substances (PFAS), parabens, and polycyclic aromatic hydrocarbons with RBC folate concentrations in 41,433 participants ages 1-80 from the U.S. National Health and Nutrition Examination Survey (2007-2016). We triangulated evidence from three statistical methods developed to examine chemical mixtures: Exposome Wide Association (ExWAS), Bayesian Kernel Regression (BKMR), and SuperLearner with G-computation. We examined the individual and joint associations of these chemicals with RBC folate concentrations, while adjusting for confounders. Results: The geometric mean RBC folate was 463 ng/mL (Interquartile range: 361 - 587.2 ng/mL). Some metals, PFAS, phthalates, and cotinine were consistently associated with lower RBC folate concentrations. Using BKMR, an interquartile range increase in perfluorononanoic acid (PFNA), cotinine, mono-ethyl phthalate, and lead was associated with a -0.15 standard deviation (SD) (95% confidence interval (CI): -0.23, -0.07), -0.11 SD (95% CI: -0.17, -0.03), -0.03 SD (95% CI: -0.07, 0.02), and -0.18 SD (95% CI: -0.25, -0.10) decrease in RBC folate concentrations, respectively. Estimates differed slightly between methods, but these findings remained robust. Conclusion: This study, which is the first to examine an association between a mixture of environmental chemicals and RBC folate concentrations in a nationally representative sample, may help enhance our understanding of the interplay between environmental chemicals, folate, and adverse health outcomes.