I have vit b 12 injections every 3 month the Dr wants me to take the same orally dose 1.000 up daily in between! I am stable at present having had non Hodgkin's lymphoma. However in May I had a new air tic valve and two stents. I am permanently tired and haveb IVIG PREMARIN INFUSION EVERY 28 days.. Ou consider more oral vit b 12 appropriate and safe when I am still so lethargic? What are the side affects I'd with the three monthly injections could this be too much medication? Sorry I have lost confidence having been so I'll.. I look forward to your response. Thank you very much..