No one knows for sure what a BPs nutritional requirements are, because they haven't been scientifically studied. However, in the wild, they eat rodents. Not rodents with vitamin supplements. Plus there are hundreds of thousands of BPs in captivity that are thriving on a diet of rodents, without any vitamins. So I consider it a pretty safe bet that a diet of rodents meets the needs of my BPs and do not give them any additional supplements.
Reptile vitamins are typically good for animals such as certain lizards, turtles, and other species that in the wild eat a very varied diet. This is pretty much impossible to duplicate in captivity, so a supplement is a good idea. Plus, many of these species are susceptible to that calcium-deficiency bone disease that I can't remember the name of right now, and they apparently are less likely to have that problem if they have been given a supplement. So if/when I own one of those species, I definitely will give the supplements.