Deficiency of which of the following vitamins leads to lactic acidosis?
**Core Concept**
The question tests the understanding of vitamin deficiencies and their impact on metabolic pathways, specifically the correlation between a particular vitamin and the development of lactic acidosis. Lactic acidosis is a condition characterized by the accumulation of lactate in the body, often due to impaired oxidative metabolism.
**Why the Correct Answer is Right**
Deficiency of **thiamine (Vitamin B1)** leads to impaired pyruvate dehydrogenase activity, an enzyme crucial for converting pyruvate into acetyl-CoA for entry into the citric acid cycle. Without sufficient thiamine, pyruvate is shunted towards lactate production, resulting in lactic acidosis. This is particularly relevant in the context of beriberi and Wernicke-Korsakoff syndrome.
**Why Each Wrong Option is Incorrect**
**Option A:** Deficiency of this vitamin does not directly lead to lactic acidosis.
**Option B:** Similarly, a deficiency in this option does not cause lactic acidosis.
**Option D:** This option is also incorrect as its deficiency is not associated with lactic acidosis.
**Clinical Pearl / High-Yield Fact**
Remember, thiamine deficiency can lead to severe neurological and cardiovascular issues, and its supplementation is critical in patients at risk, such as those with poor nutrition or chronic alcohol use.
**Correct Answer:** D. Thiamine