A 30-year-old chronically malnourished male presented to the OPD with complaints of weakness, lassitude, anorexia along with poor appetite, abdominal discomfo and diarrhea. There is also evidence of apathy, lethargy and mild disorientation in the patient. On examination Glossitis Dermatitis in sun exposed areas All of the following enzymes uses the above deficient vitamin as a coenzyme except: –

**Core Concept**
The question is testing the knowledge of the clinical manifestations and biochemical implications of a specific vitamin deficiency, particularly in the context of chronic malnutrition. The vitamin in question is likely **Vitamin B12**, which plays a crucial role in the synthesis of myelin, maintenance of the nervous system, and the metabolism of fatty acids and amino acids.

**Why the Correct Answer is Right**
Vitamin B12 deficiency can lead to a range of clinical symptoms, including weakness, lassitude, anorexia, abdominal discomfort, diarrhea, apathy, lethargy, and mild disorientation. These symptoms are due to the impaired synthesis of myelin, the breakdown of fatty acids and amino acids, and the disruption of the nervous system. The enzymes that rely on Vitamin B12 as a coenzyme include **Methylmalonyl-CoA mutase** and **Methionine synthase**.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, so we'll move on to the next one.
**Option B:** This option is also not provided.
**Option C:** This option is also not provided.
**Option D:** This option is also not provided.

However, since the correct answer is given as an empty option, let's assume the question is asking about a specific enzyme that does not use Vitamin B12 as a coenzyme. In that case, we can consider the options given below:

**Option A:** Transketolase (uses Thiamine pyrophosphate as a coenzyme)
**Option B:** Aldehyde dehydrogenase (uses NAD+ as a coenzyme)
**Option C:** Pyruvate dehydrogenase (uses Thiamine pyrophosphate as a coenzyme)
**Option D:** Malate dehydrogenase (uses NAD+ as a coenzyme)

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Vitamin B12 deficiency can lead to neurological symptoms, including weakness, fatigue, and cognitive impairment, making it a critical diagnosis to consider in patients with chronic malnutrition.

**Correct Answer:** Correct Answer: .

✓ Correct Answer: D. Transaminase