Given his lack of energy, weakened immune response, facial rash, and irritability, which b vitamin might simon the most

Given his lack of energy, weakened immune response, facial rash, and irritability,  vitamin B6 might help Simon the most.
The Vitamin 6 is responsible for key-metabolic processes, maintains a healthy nervous system, helps the body fight infections.
Vitamin B6 deficiency is characterized with anemia, depression, confusion, abnormal brain wave pattern,  rashes, scaly dermatitis...