Can you overdose on Vitamins?
You can over dose on fat soluable vitamins which are vitamins A D E and K, or rather they can be come toxic in your body if you take too much of them. Fortunately B vitamins are water soluable so whatever you don't use are excreted. My surgeon also requires very high amounts of B vitamins. This might be too much information but my pee is always bright orange in the morning because of the B vitamins I take at night so it seems pretty obvious that what isn't getting used is leaving my body. Unless you start feeling badly I would keep doing what your surgeon tells you and trust that he knows how much would be too much.
If you google B vitamins you'll get all kinds of information on what they do for you and and any possible effects of taking high dosages of them.
Corinna Q