Megaloblastic anemia is associated with deficiency of-

RUHS, Jaipur, PB B.Sc Nursing Entrance-2023

Pathology & Genetics

Easy

Appeared in: RUHS, Jaipur, PB B.Sc Nursing Entrance-2023

Explanation

Megaloblastic anemia results from impaired DNA synthesis, a process that requires both Vitamin B12 and folic acid as essential cofactors.
A deficiency in either nutrient disrupts the normal maturation of red blood cells in the bone marrow, leading to so-called nucleocytoplasmic asynchrony.
This results in the production of abnormally large and immature red blood cells (megaloblasts), which are released into circulation as macrocytes.
Because a deficiency in either vitamin can cause the condition, the option that acknowledges both is the most comprehensive and accurate description.

Option A: This option is incomplete. While a deficiency of Vitamin B12 alone does cause megaloblastic anemia (e.g., pernicious anemia), folic acid deficiency is an equally important and common cause.
Option C: Iron deficiency impairs the synthesis of hemoglobin, not DNA. This leads to microcytic (small) and hypochromic (pale) anemia, which is morphologically distinct from the macrocytic cells seen in megaloblastic anemia.
Option D: Zinc deficiency is not a primary cause of megaloblastic anemia. It is more commonly associated with impaired immune function, delayed wound healing, skin lesions, and growth retardation.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Etiology of Megaloblastic Anemia as background academic context rather than a clinical decision trigger.
Nurses play a key role in educating patients on dietary sources of Vitamin B12 (animal products, fortified foods) and folic acid (leafy green vegetables, legumes, fortified grains) to prevent deficiencies.
It is critically important to determine whether the cause is B12 or folate deficiency. Treating a B12 deficiency with folic acid alone can resolve the anemia but will not stop the progression of potentially irreversible neurological damage.
What if? If a patient with megaloblastic anemia also presents with neurological symptoms like paresthesia (tingling in hands/feet) or ataxia (poor balance), the cause is almost certainly Vitamin B12 deficiency. This requires immediate B12 supplementation to prevent permanent nerve damage.

How to Approach the Question

This is a factual recall question testing knowledge of hematological disorders.
First, identify the key term in the question stem: 'Megaloblastic anemia'.
Recall the pathophysiology associated with this term. 'Megalo-' means large, which refers to the characteristic large, immature red blood cells (macrocytes).
Connect this abnormal cell morphology to its underlying cause: impaired DNA synthesis during red blood cell production (erythropoiesis).
Recall the two primary nutrients that are essential cofactors for DNA synthesis: Vitamin B12 and folic acid.
Evaluate the given options. Option B includes both of these key nutrients and is therefore the most complete and correct answer.

Concept Tested & Keywords

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