This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
[{'content': 'Deficiency of which vitamin during pregnancy predisposes to meningomyelocele? \nSelect and explain. \nA. Folic acid, B. Biotin, C. Pyridoxine, D. Thiamine', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Folic acid* Isolated (ie, nonsyndromic) NTDs (neural tube defects) are congenital malformations that result from failure of the neural tube to close during embryogenesis. Normally, the primordial central nervous system begins as a plate of cells early in embryonic life, which folds on itself to form a tube. Closure of the tube occurs in the interval of days 21-28 postconception. Failure of closure results in NTDs.* They are of three types :# Spina Bifida Occulta# Meningocele# Myelomeningocele* Among environmental factors, Nutrition is considered the main factor. Regarding nutritional deficiencies, many case control studies and randomised controlled trials have proven that maternal Folic acid deficiency is the most common cause for Foetal Neural Tube Defects.", 'role': 'assistant'}]