**Core Concept**
Inhibitors of Isoniazid (INH)-induced neuropathy are related to pyridoxine (Vitamin B6) deficiency. INH interferes with the metabolism of pyridoxine, leading to a decrease in pyridoxal phosphate, an essential cofactor for neurotransmitter synthesis and myelin maintenance.

**Why the Correct Answer is Right**
The mechanism of INH-induced neuropathy involves the interference with pyridoxine metabolism, specifically the reduction of pyridoxal phosphate levels. This decrease impairs the synthesis of neurotransmitters, such as serotonin and dopamine, and disrupts the myelin sheath, leading to nerve damage. The deficiency of pyridoxal phosphate is a critical factor in the pathogenesis of INH-induced neuropathy.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as INH-induced neuropathy is not directly related to the metabolism of folate. While folate is essential for one-carbon transfer reactions, its deficiency is associated with different clinical manifestations, such as megaloblastic anemia.
**Option B:** This option is incorrect as the relationship between INH-induced neuropathy and vitamin B12 is indirect. Vitamin B12 deficiency can cause neuropathy, but it is not a direct consequence of INH treatment.
**Option C:** This option is incorrect as pyridoxine supplementation is a well-established treatment for INH-induced neuropathy. The correct answer is the option that does not increase in INH-induced neuropathy.

**Clinical Pearl / High-Yield Fact**
To prevent INH-induced neuropathy, patients should receive pyridoxine supplementation, especially those with a history of neuropathy or those taking high doses of INH.

**Correct Answer: D. Pyridoxine**