Does B12 Help You Lose Weight? Kansas City Med Spa How often should vitamin B12 injections be administered and how frequently should laboratory monitoring be performed? How Often Should I Take Vitamin B12 Injections If you have a low vitamin B12 level, injections can go a long way toward improving your health and well being. But if your B12 level is normal, don't fall for claims that B12 Shots Benefits & How to Use Them For Weight Loss B12 Injections: How Often Should You Take Them? Invigor Medical