Ultrasound examination of a developing fetus demonstrates a fluid-filled sac at the base of the fetus' spine that connects to the spinal canal and apparently contains pa of the spinal cord. A dietary deficiency of which of the following is most strongly associated with this type of lesion?

The lesion is a neural tube defect, probably a meningomyelocele, in which both meninges and spinal cord herniate through a bony veebral defect. These defects most commonly occur in the lumbosacral region, typically resulting in motor and sensory deficits in the lower extremities, and bowel and bladder dysfunction. This condition is now known to be associated with low maternal folate during the first three to four weeks of pregnancy, a time when many women may be unaware of their pregnancy. It is now recommended that all women of childbearing age consume at least 400 mg of folic acid daily. Calcium deficiency can cause osteoporosis and osteopenia. Iron deficiency can cause iron deficiency anemia. Vitamin C deficiency can cause scurvy. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 13. Prenatal Diagnosis and Fetal Therapy. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.