Folic acid fortification has been credited with significant reductions in neural tube defects since its implementation in 1998. However, accumulating evidence reveals that synthetic folic acid operates through mechanisms distinct from natural folates, with consequences extending far beyond the one-carbon cycle. This paper proposes the Synthetic Folate Disruption Hypothesis (SFDH): that folic acid causes multi-vector methylation interference through at least five distinct but interconnected mechanisms: (1) dihydrofolate reductase (DHFR) saturation leading to unmetabolized folic acid (UMFA) accumulation; (2) pseudo-MTHFR syndrome induction in genetically wild-type individuals; (3) holotranscobalamin (holoTC) depletion causing functional B12 deficiency independent of classic masking; (4) competition with 5-MTHF for cellular uptake via folate receptors and transporters; and (5) downstream bioelectric destabilization—including altered membrane excitability, seizure threshold instability, and disrupted voltage gradient signaling—through altered ion channel methylation. Relationship to existing literature: Mechanisms 1-4 are documented in existing literature and are synthesized herein with full attribution: DHFR saturation (Bailey & Ayling, 2009), pseudo-MTHFR (Christensen et al., 2015; Cornet et al., 2019), holoTC depletion (Selhub et al., 2022; Miller et al., 2024), and receptor competition (Smith et al., 2008). This paper does not claim to have discovered these mechanisms. Novel contributions of this paper: The SFDH extends existing literature by: (1) integrating these five mechanisms into a unified framework proposing they are interconnected nodes of a single disruption pattern converging on the NADPH-GSH-SAM metabolic hub; (2) introducing the bioelectric extension—connecting folic acid disruption to ion channel methylation and bioelectric signaling, a domain not previously linked in folic acid literature; (3) analyzing environmental convergence with other methylation disruptors (seed oils, glyphosate, fluoride, cyanocobalamin); (4) integrating with the Bioelectric-Methylation Interface Hypothesis (BMIH) and the Cobalt Preservation Hypothesis (companion frameworks; see Related Frameworks in References) and (5) providing explicit falsifiability criteria distinguishing this as a testable hypothesis rather than a narrative review. This framework suggests that what presents as MTHFR dysfunction, B12 deficiency, or unexplained methylation-related symptoms may often represent folic acid-induced interference—a modifiable exposure rather than a fixed genetic constraint. Keywords: folic acid, folate, UMFA, unmetabolized folic acid, DHFR, MTHFR, pseudo-MTHFR, holotranscobalamin, holoTC, methylation, one-carbon metabolism, bioelectrics, ion channels, KCNQ, SAM, homocysteine, neural tube defects, hypothesis