After battles with my GP re B12 and my most recent blood test (700) I was told I did not need any further injections. I had been requesting them more frequently because of tingling fingers and toes, brain fog, tinnitus, blurry eyes, etc! I argued that I would accept her ruling if I had a definite diagnosis and suggested that blood tests for homocysteine and MMA, I had read, were the way to go. To my surprise I have just received a letter asking me to present myself for a fasting blood test before my next injection due date but that I must be prepared to 'rush' it to the local hospital as it had to be tested within 30 minutes of extraction. I take oral supplements and sublingual spray and would bea most grateful for any advice or comment.