M.B.
Hi. I did a research proposal for one of my research psychology classes in college, and it was based on the effects of sublingual (under-tongue drops) of Vitamin B12 in people with anxiety and depression. Overall, it did seem to help, because like someone who posted before me said, a deficiency in the B vitamins does affect the personality with regard to anxiety and depressive symptoms. It is worth a shot, and it couldn't hurt. Sublingual B12 can be purchased at the health food store relatively inexpensively. Some even have other B vitamins included, which is great.
Best of luck to you.