mrsD, I hadn't read your post here before I sent it off in PM. Sorry about that.

Full article here... Totally over my head unfortunately

[Also note limitations with such a small sample size.]

http://journals.plos.org/plosone/art...0146797#sec009

Research Article PLOS ONE
Decreased Brain Levels of Vitamin B12 in Aging, Autism and Schizophrenia
Published: January 22, 2016
DOI: 10.1371/journal.pone.0146797