Concept:
Isoniazid is a first-line antitubercular drug. It is very effective against tuberculosis, but it can cause some adverse effects.
Step 1: Common adverse effect of isoniazid.
One important adverse effect of isoniazid is peripheral neuropathy. Peripheral neuropathy may present as tingling, numbness, burning sensation, or pain in hands and feet.
Step 2: Cause of neuropathy.
Isoniazid interferes with vitamin B\(_6\), also called pyridoxine, metabolism. Deficiency of pyridoxine increases the risk of neuropathy.
Step 3: Preventive measure.
To prevent this adverse effect, vitamin B\(_6\) is given prophylactically along with isoniazid.
Step 4: Checking other vitamins.
Vitamin K is related to blood clotting.
Vitamin C is related to collagen synthesis and antioxidant function.
Vitamin A is related to vision and epithelial health.
Vitamin B\(_6\) is specifically used with isoniazid to prevent neuropathy.
Step 5: Final answer.
Therefore, vitamin B\(_6\) should be given prophylactically with isoniazid.
\[
\boxed{\text{Vitamin B}_6}
\]