Benefits of Vitamin B12 Injections for Skin Main benefits of B12 injections 1) Increased energy & reduced fatigue B12 helps convert food into usable energy Deficiency often causes tiredness, weakness, and low stamina 2) Healthy red blood cells Prevents What is the recommended frequency for monitoring Vitamin B12 levels in patients receiving intramuscular (IM) Vitamin B12 injections for replacement therapy? B12 level 99 ng L. Is this really low or just a little low? How often for injections? : r B12_Deficiency