I understand that a number of CFS doctors are prescribing high doses of vitamin B12, supposedly to remove the toxic nitric oxide in our bodies, and often at the same time prescribing antivirals such as Valcyte or Nexavir. It is with great astonishment then, that after considerable reading of articles on the Pubmed database and other websites, that there seems to be considerable evidence that nitric oxide is itself an antiviral produced by the body's immune system in response to infection. This leaves me with the question then of why we would want to remove it if we are following an antiviral treatment? Do any patients of Cheney or Kenny De Mielier (or other CFS doctors) have any idea of how these doctors would respond to this question? One example of an article is as follows: http://www.ncbi.nlm.nih.gov/pubmed/15479821?ordinalpos=8&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_DefaultReportPanel.Pubmed_RVDocSum A search in pubmed using the combination or 'nitric oxide HSV', 'nitric oxide EBV' or 'nitric oxide herpes' will reveal countless such articles, although there does not seem to be much on HHV6. I am taking B12 injections myself at the moment in line with my doctors advice, but am not yet taking antivirals - though am considering them (but now wonder if I should stop the B12?). Megan (very puzzled).