The nurse is providing preconception counseling. Which supplement should the nurse recommend to help prevent the occurrence of anencephaly?

Choice A rationale Iron is essential for preventing anemia, particularly in pregnant women, but it does not prevent neural tube defects like anencephaly. Iron supports overall maternal and fetal health but is not specific to preventing congenital anomalies. Choice B rationale Calcium is crucial for fetal bone development and maternal bone health, but it does not play a role in preventing anencephaly. Adequate calcium intake is important during pregnancy but is not linked to neural tube defect prevention. Choice C rationale Vitamin D is important for bone health and immune function but does not prevent neural tube defects. Sufficient vitamin D levels are necessary for the mother's and baby's health but are not related to anencephaly prevention. Choice D rationale Folic acid is the correct choice as it has been shown to prevent neural tube defects, including anencephaly and spina bifida. It is recommended that women of childbearing age take folic acid supplements before conception and during early pregnancy to reduce the risk of these congenital anomalies.