I’ve learned that you can’t trust most food and drug companies with your health. You’ve got to read the label on anything you consume, including vitamins.
Someone I know purchased a a bottle of popular, heavily-advertised vitamins from a store last year. It wasn’t agreeing with their stomach and I took a look at the label. I have no idea what caused their issue, but I noticed two things I didn’t like: Maltodextrin and Cellulose. The first is an artificial sweetener and the last has many uses including anti-caking and thickening.
It’s tough finding a vitamin with harmless ingredients, but look for ones with the fewest additives – that’s what I do.