As also described in other recessions, I had (64 m) to deal with "brain fog". Describe Hardly, but I was also nervous, irritable and unfocused. And nowhere is this condition made while golfing noticeable. But with absolute certainty that was already made for me unnoticed to a professional problem. Purely by chance I came across the book by Dr. John Switzer. There was actually very well explained, such as vitamin B12 deficiency makes itself felt and which can be caused. After a review of the causes, it was clear to me that I could be a candidate. Since I had the neurologist a vitamin B12 supplement recommended in a dosage that covered exactly the daily requirement also to suffer polyneuropathy. Earlier I had very positive tests with higher doses. Since I now occupying this preparation which corresponds indeed an almost 40-fold coverage of the daily requirement I am a different person. I'm wide awake, no longer nervous and irritable and can concentrate extremely well again. Now I hope that this preparation has no adverse long-term side effects.