This has come up several times, and some vendors sell vitamin
e-liquid. The fact is, however, that you would have to vape an enormous amount to get the same amounts as from a pill taken internally. Heat will decompose many vitamins, like vit-C, and most are pretty large molecules and do not vaporize easily.
Truthfully, I do not think
vaping vitamins is at all effective for ingesting them, and seems to me just a gimmick at best, atty-killer at worst.
Fact: not all compounds are best ingested by
vaping.