I never heard of it for humans. However, it makes sense if there is a deficiency in the B vitamins. However, for neuropathy, there is no deficiency that i know of just that the methyl B12 helps. The Texas A&M U recommendation for B12 only discusses B12: http://vetmed.tamu.edu/gilab/research/c ... nformation
A very long time ago, while working a drug abuse hotline, I came across that infobit. It may have been from Drug Facts and Comparisons or from the nutrition textbook I read.