Staying healthy this time of year starts at the cellular level, and B12 plays a major role., Vitamin B12 supports energy production, nervous system function, red blood cell formation, and immune NAD+ vs. B12: What's the difference? NAD+ supports cellular energy, metabolism, and longevity at the mitochondrial level. B12 helps with red blood cell production, nerve health, and energyespecially if you're deficient. B12 Injections vs Supplements: 16 Key Facts Explained Benefits of B12 Injections for Optimal Health