A nurse is teaching a newly pregnant client about early prenatal care. Which of the following instructions is MOST important to give regarding folic acid?

FOLIC ACID supplementation is one of the most strongly evidence-based prenatal interventions. Adequate folic acid intake reduces the risk of NEURAL TUBE DEFECTS (NTDs) — most critically spina bifida (incomplete closure of the spinal column) and anencephaly (absence of major brain structures). The NEURAL TUBE closes by 28 days after fertilization — often before a woman even knows she is pregnant. This is why folic acid is recommended BEFORE CONCEPTION and throughout at least the FIRST TRIMESTER. DOSE: the CDC and ACOG recommend 400-800 mcg/day for all women of childbearing age; women with a history of a prior NTD pregnancy should take 4 mg/day (400 mcg = 0.4 mg; 4 mg is 10x the standard dose — prescription-strength). FOOD SOURCES of folate: leafy green vegetables (spinach, kale), fortified cereals and bread, beans, citrus fruits, nuts. Since 1998, US grain products have been mandated to be fortified with folic acid. PN TEACHING POINTS: emphasize that folic acid must be started BEFORE PREGNANCY for maximum benefit; use simple language ('folic acid helps prevent serious birth defects of the brain and spine'); confirm they understand the dose and can identify a folic acid supplement; note that prenatal vitamins typically contain the required amount. Additional first-trimester teaching: avoid alcohol, smoking, illicit drugs; limit caffeine; avoid raw meats, unpasteurized cheeses, high-mercury fish; take prenatal vitamins including iron; establish OB care as early as possible; be alert to warning signs (heavy bleeding, severe abdominal pain, fever).