Can I ask why you are so interested in vaping weird stuff. I'm quite certain that normal, sublingual B vitamins are both cheaper, and more effective, when swallowed or ingested. Vaping things like B vitamins and aloe vera OR anything else besides e-juice in a vaporizer will be ineffective (even if marketed by an e-juice company) at best, and uselessly health decreasing as you vape, at worst. You just read several posts about how adding non-recommended items such as aloe vera and you come back asking about vitamin B?
To be clear, this site doesn't sanction those types of "experiments." This is a harm reduction site, not a "what non-studied items can I vape" site. If you really want to try it, I certainly can't stop you and I'm glad you are ASKING, but is there a reason you want to make vaping "healthy" or different than what it is? Vaping is a harm reduction device to stop using nicotine, for the most part, and starting out with questionable materials is only going to make things difficult or unhealthy for you, and I don't quite understand your desires in this direction.
Best of luck. Things to vape: Normal e-juice, find some flavors you like, and you're done. Period.
Anna