Question

A 38-year-old man from a rural area presents with progressive fatigue, pedal edema, and breathlessness. He reports consuming mainly polished white rice for several months with minimal protein intake. Examination reveals tachycardia, bilateral pedal edema, and elevated jugular venous pressure. No murmurs are heard. Which of the following vitamin deficiencies is the most likely cause of his condition?

• A. Vitamin B2
• B. Vitamin B1
• C. Vitamin B6
• D. Vitamin B12

Hint:

Vitamin B1 (Thiamine) Deficiency Syndromes:
1. Wet Beriberi: Cardiovascular involvement (dilated cardiomyopathy, high-output heart failure, edema).
2. Dry Beriberi: Neurological involvement (symmetrical peripheral polyneuropathy, muscle wasting).
3. Wernicke-Korsakoff Syndrome: Central nervous system involvement (confusion, ataxia, nystagmus, confabulation).

Answer 1

The Correct Option is B

Concept:
A young adult male originating from a rural area presents with textbook clinical signs of overt, biventricular congestive heart failure, specifically characterized by marked breathlessness, resting tachycardia, massive bilateral pedal edema, and elevated jugular venous pressure.
The highly critical diagnostic clue is his severely restricted dietary history, consisting almost exclusively of consuming processed, polished white rice. The clinical goal is to identify the specific nutritional vitamin deficiency responsible for causing this severe, high-output cardiac failure.
Explanation:
• The patient's severe clinical presentation perfectly describes "Wet Beriberi," a dangerous and potentially fatal cardiovascular syndrome caused exclusively by a severe, systemic deficiency of Vitamin B1, which is chemically known as Thiamine.

• The process of milling and polishing white rice completely strips away the outer bran and germ layers of the grain, which are the components that contain nearly all the essential vitamins, most notably thiamine. Populations relying on polished rice as their absolute staple caloric source are historically at massive risk for this deficiency.

• Biologically, Thiamine serves as a mandatory coenzyme (as thiamine pyrophosphate or TPP) for several critical enzymes in cellular carbohydrate metabolism and ATP production, specifically including pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in the TCA cycle.

• A profound lack of thiamine leads to a massive failure of cellular energy production. In the cardiovascular system, this metabolic failure causes severe, widespread peripheral vasodilation, dropping systemic vascular resistance dramatically.

• To compensate for this massive drop in resistance and maintain blood pressure, the heart is forced to drastically increase its cardiac output (presenting as the resting tachycardia), leading directly to a high-output cardiac failure state.

• Furthermore, the direct metabolic injury to the myocardial cells severely impairs their contractility, exacerbating the florid heart failure, which leads to fluid retention, elevated JVP, and the massive pedal edema (the "wet" aspect of beriberi).

• Vitamin B2 (Riboflavin, Option A) deficiency causes angular cheilitis and glossitis.

• Vitamin B6 (Pyridoxine, Option C) deficiency causes peripheral neuropathy and sideroblastic anemia.

• Vitamin B12 (Cobalamin, Option D) deficiency causes megaloblastic anemia and subacute combined degeneration of the spinal cord, none of which present with isolated high-output heart failure.
Final Answer:
The consumption of a thiamine-poor diet of polished rice leads to Vitamin B1 deficiency, causing the high-output heart failure classically known as Wet Beriberi.