Tricyclics and Multi-vitamins?

I'm taking a tricyclic anti-depressant (amitriptyline) and read that many of the side effects can be due to a lack of vitamin B, so i've started taking Swiss multi-vitamins. I've also read that multi-vitamins can actually enhance the effectiveness of the tricyclic (with the possible exception of vitamin C). I was just wondering if anybody had actually taken these two medications together, and what the effects were.