Travelling on a train to Scotland, all for the first time: Clinical researcher says: "Look the cows in Scotland are black!". Physicist replies: "No. Some of the cows in Scotland are black" Mathematician says: "No, actually in Scotland there is at least one cow black on one side" I’ve written about folic acid, homocysteine and various clinical trials of nutrients in the past. I just want to revisit it briefly because I think there are some seriously wrong messages emerging from the conclusions. For an excellent comment on evidence based recommendations see Colby Vorland . Homocysteine (Hcy) is associated with CVD, may or may not be causal but the evidence is good (Wald et al , BMJ, 2002). Folic acid (Vitamin B9) in reasonable amounts will lower homocysteine but clinical trials have been carried out, mostly showing not much benefit as far a CVD is concerned. A recent meta-analysis of 8 trials (total 37,485 individuals) seems t...