There was a post today in Vitiligo Pride Facebook group, (which if you are on Facebook, & comfortable discussing your Vit, I highly suggest joining.) by a member concerning Folic Acid. She had never been told by her doctor that she may need it. I thought I would do some reading & research about it as I didn't know either. It seems that the combination of Folic Acid & B12 can have benefits for those of us with Vitiligo.
You can read more at these sites.
I would also suggest this link to familarize yourself
with which herbs to avoid that can do more damage
than good since we do have an autoimmune.