"Drops" are usuaally a tincture, or extract, involving Neutral Spirits {ie: Ethyl Alcohol}. There are glycerin based which I guess is alright - But they are generall not as effective as the alcohol-based and/or actually have different affects than the more commonly researched alcohol-bases of the sdame herbal...
To some degree herbals are ok in little moderation...However how many of us are actually procurring the plants & preparing them? At least tear open the capsules & toss the Gelcaps.
"Vitamins" & pills are more than 90% *inert* ingredients, ie: AVOID, especially during a fast...
Bottomline during a *Fast* - If you are worried about vitamins its after the fast when you reintroduce the foods, do the research and ingest the food/plant versions of the said vitamins.