Seems like thiamine has a role with regard to NAPDH as well:

"Thiamine is an essential coenzyme
for transketolase, which is part of the pentose phosphate
pathway that maintains cellular NADPH levels. Thiamine
is cytoprotective and restores NADPH levels, glyoxal
detoxification and mitochondrial membrane potential in
hepatocytes with glyoxal toxicity [97]. NADPH
cytochrome c-reductase levels are increased in TD animals
[98]. Benfotiamine treatment under normo- and hyperglycemic
conditions significantly down-regulates Nox4
expression [99]. Animals that are fed a high-thiamine diet
exhibit approximately 57% of the NADPH-cytochrome c
reductase activity of animals that are fed a TD diet [100].
The data suggest a role for thiamine in, protecting
schizophreniavia the regulation of NADPH-cytochrome c
activity."

Link: http://article.sciencepublishinggrou...0130103.11.pdf (this was a study concerning schizophrenia, but still).