Vitamin B12 Injections: What You Need To Know Feeling exhausted, run down, foggy or low this winter? Cold weather, darker days and busy schedules can drain your energy fast and that's where a B12 injection can make all the difference Why Do I Feel Worse After My B12 Injection? Understanding Post Injecti Oxford Origins I Feel Tired All the Time. Do I Need a B12 Shot?: Shawn Veiseh, M.D.: Family Medicine Feeling tired all the time? It might not just be life., Low vitamin B12 can leave you feeling exhausted, foggy, weak or run down, and many people dont realise theyre deficient., In this video, our