I mean, there are literally multivitamin gummies at any decent grocery store. If you want a processed food snack that’s got vitamins that’s where I’d start.

My advice, being on the spectrum myself, would be to be open about the fact that they’re multivitamin gummies, ie don’t try to lie and present them as “desert”. But tell him you’d like to treat them as desert even though they aren’t so he can help get some vitamins.