PREconception Folic Acid Clinical Efficacy (PREFACE) Trial

Inclusion Criteria: * Non-pregnant females who are: * Currently trying to become pregnant; * Aged 19-42 years; * Low risk for an NTD-affected pregnancy Exclusion Criteria: * Trying to conceive for ≥6 months (as \~90% of pregnancies occur after 6 months of trying); * Diagnosed ovulatory disorders (polycystic ovary syndrome, endometriosis, or menstrual irregularity); * More than 2 miscarriages in the past year; * Undergoing fertility assistance (including current IVF or intrauterine insemination); * Pre-existing medical condition known to impact maternal folate status (malabsorptive and inflammatory bowel diseases, active celiac disease, gastric bypass surgery, type 1 or 2 diabetes mellitus); * Lifestyle factors known to impact maternal folate status (current smoking, \>6 alcoholic drinks per week, recreational drug use); * On the female or male side of those trying to conceive: personal NTD history, previous NTD-affected pregnancy, or personal or family history of other folate sensitive congenital anomalies; * Use of folate-inhibiting medications (Chloramphenicol, Methotrexate, Metformin, Sulfasalazine, Phenobarbital, Phenytoin, Primidone, Triamterene, Barbiturates).