A maternal deficiency of which B vitamin in early pregnancy is linked to neural tube defects such as spina bifida?

1. The neural tube forms early in embryonic development from ectoderm, through a process called neurulation. 2. Proper closure of the neural tube depends on adequate maternal nutrition. 3. Folate specifically as critical for this healthy development. 4. A maternal folate deficiency in the first weeks of pregnancy is linked to neural tube defects, including spina bifida and anencephaly. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 28 "Development and Inheritance", p.1334 §Organogenesis_