Which of the following vitamin is important for nerve health?

Vitamin B complex, especially B12, is essential for neuronal myelin sheath synthesis and axonal conduction. Deficiency causes peripheral neuropathy, paresthesia, ataxia, and subacute combined degeneration of spinal cord demyelination present. Vitamin B12 deficiency results from pernicious anemia, malabsorption, or alcoholism, leading to dorsal column dysfunction, loss of vibration sense, and symmetric distal neuropathy. Serum levels <200 pg/mL confirm deficiency with neurologic involvement. Rationale: A. Vitamin B supports myelin sheath formation and neuronal conduction processes. Deficiency leads to peripheral neuropathy and cognitive dysfunction including memory. Option correctly identifies vitamin B as essential for nerve integrity. Prevents demyelinating neurologic disease and supports normal nervous function activity. B. Vitamin D regulates calcium homeostasis and bone metabolism functions system. Deficiency causes osteomalacia muscle weakness and neuromuscular irritability symptom progression. Vitamin D is not primary vitamin for peripheral nerve health. It indirectly affects nervous system through calcium signaling pathways regulation. C. Vitamin C is essential for collagen synthesis and antioxidant function. Deficiency leads to scurvy bleeding gums and impaired wound healing. It does not play primary role in nerve myelination processes. Neurological benefits are indirect via reduction of oxidative stress damage. D. Vitamin A supports visual pigment rhodopsin formation in retina function. Deficiency causes night blindness and epithelial tissue keratinization progression severity. It is not primary nutrient for peripheral nerve maintenance function. Neurological role mainly involves visual pathway rather than nerves health.