A nurse is teaching a pregnant client about preventing neural tube defects. Which supplement is most important?

FOLIC ACID (folate) is most important for preventing NEURAL TUBE DEFECTS (such as spina bifida and anencephaly). NCLEX-RN health promotion/prenatal care. Recommendations: women of childbearing age should take about 400 mcg of folic acid daily, and pregnant women typically 600 mcg — IDEALLY STARTING BEFORE CONCEPTION and in early pregnancy, because the neural tube closes within the first 28 days (often before a woman knows she's pregnant). Folate sources: fortified grains, leafy greens, legumes, citrus. Starting folic acid before and during early pregnancy is the key preventive measure. Knowing folic acid prevents neural tube defects (and the timing) is a heavily tested prenatal health-promotion concept.