Question - My mother in law uses moth balls for everything. Moth balls are not all made of the same substance.
Common chemicals used for moth balls are naphthalene, p-dichlorobenzene, and camphor.
These compounds have different toxicities, but none of them are exactly vitamins. At least, moth balls don't smell like anything I want to eat. Of course, there are many different reasons for people to get sick. The mothballs should certainly be mentioned to her doctor if she's having some sort of trouble. I don't have numbers for the toxicity of naphthalene.