I am a 61 year male who until 6 months ago considered myself fit and well, although for the previous 2 years I had been going slowly downhill which I just put down to getting older. I was eventually forced to admit that something was wrong and blood tests revealed b12 of around 140. I have lots of neurological symptoms including twitching and muscle spasms when asleep. I had the course of 6 jabs from my GP, which worked a bit as far as energy levels are concerned and my b12 rose to about 450. The effect of the jabs quickly wore off. I am now self injecting every other day at present, my energy levels and what I would call speed of brain are starting to come back to a more respectable level. I no longer feel the urge to simply drop asleep whenever I sit down for more than a couple of minutes. My big concern at present is my low blood pressure and fast heart rate. All my adult life my bp has been in the order of 120/70. These days it barely rises above 95/60 and has been as low as 75/50. this is a concern as there is barely enough pressure to suffuse peripheral parts of the body. my heart rate is also prone to rise on gentle exercise to as much as 170bpm. Has anybody else out there experienced such and do you have any advice for me please?