Neural Tube Defects are due to a deficiency of which Vitamin?

AIIMS Delhi NO - 2017

Obstetrics & Gynaecology

Easy

Appeared in: AIIMS Delhi NO - 2017

Explanation

Folic acid, also known as Vitamin B9, is essential for the synthesis of DNA, RNA, and proteins, which are the building blocks of cells.
The neural tube is the embryonic structure that develops into the brain and spinal cord. It forms and closes between the 3rd and 4th week after conception.
A deficiency in folic acid during this critical period disrupts rapid cell division and differentiation, leading to incomplete closure of the neural tube.
This failure of closure results in neural tube defects (NTDs) such as spina bifida (an opening in the spine) and anencephaly (absence of a major portion of the brain and skull).

Option A: Thiamine (Vitamin B1) deficiency is not associated with neural tube defects.
Option C: Retinol (Vitamin A) deficiency is not the cause of neural tube defects. In fact, an excess of Vitamin A (hypervitaminosis A) is known to be teratogenic and can cause birth defects.
Option D: Ascorbic acid (Vitamin C) deficiency is unrelated to the formation of the neural tube.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain The role of vitamin deficiencies in causing congenital anomalies, specifically neural tube defects as background academic context rather than a clinical decision trigger.
Nurses play a vital role in educating all women of childbearing age about the importance of daily folic acid supplementation, not just those actively planning a pregnancy, as many pregnancies are unplanned.
Preconception counseling is a key opportunity to assess nutritional status and reinforce the need for folic acid to reduce the risk of NTDs.
What if? If a woman has a personal or family history of a neural tube defect (e.g., a previous child with spina bifida), the standard recommendation changes. She would require a much higher prescription dose of 4 mg (4000 mcg) of folic acid daily, starting at least one month before conception and continuing through the first trimester.

How to Approach the Question

This is a factual recall question that tests your knowledge of vitamins and their roles in health and disease.
First, identify the key pathology mentioned in the question stem: 'Neural Tube Defects'.
Next, systematically review the options provided, which are all different vitamins.
Recall the primary function and major deficiency disease associated with each vitamin.
Connect 'Neural Tube Defects' with the correct vitamin. The link between folic acid deficiency and NTDs is a fundamental concept in prenatal care.
Eliminate the other options by confirming their association with different diseases: Thiamine with Beriberi, Retinol with vision problems, and Ascorbic acid with Scurvy.

Concept Tested & Keywords

Concept Tested: The role of vitamin deficiencies in causing congenital anomalies, specifically neural tube defects.
Stem keywords: Neural Tube Defects, deficiency, Vitamin
Lead-in keywords: due to
Negative lead-in flag: false

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E6 Obstetrics Williams p. 81-95

E6 Medicine Davidson Principles Practice 24e p. 735-737