Note: This outline is a work in progress. Most statements draw on the technical article in Reference 1; items marked “[ref needed]” indicate areas where I plan to add specific supporting studies in a later revision.
Core thesis: B12 deficiency creates a continuous risk window beginning before conception, extending through pregnancy and lactation, and surfacing months later in infants. Without recognition and treatment, this single deficiency causes neural tube defects, recurrent pregnancy loss, preeclampsia, gestational diabetes, infant neurologic crisis, and potentially permanent developmental and metabolic harm to both mother and child.1 Standard prenatal care—which universally supplements folic acid but rarely screens for B12—can mask the deficiency while neurologic damage progresses.1,2,3 Even when B12 supplementation occurs alongside folic acid, standard serum B12 testing cannot confirm adequate cellular uptake, as most circulating B12 is bound to metabolically inactive proteins rather than the transcobalamin required for tissue delivery.1