Final answer:
Folate, or folic acid (vitamin B9), is imperative during early pregnancy to prevent neural tube defects such as spina bifida and anencephaly, with a recommended intake of at least 400 µg/day from supplements or fortified foods.
Step-by-step explanation:
Inadequate intake of folate, also known as folic acid or vitamin B9, early in pregnancy is associated with the development of about 50 percent of cases of neural tube defects. Folate deficiency during the critical first weeks of pregnancy can lead to serious birth defects, including spina bifida and anencephaly. Therefore, it is highly recommended to ensure a sufficient intake of folate through diet or supplementation.
Sources of folate include leafy green vegetables, whole wheat, fruits, nuts, and legumes. To reduce the risk of neural tube defects, the Food and Nutrition Board of the Institute of Medicine advises that all women who could become pregnant consume at least 400 µg/day of folate from supplements or fortified foods.