The usual culprits
Minerals like iron and zinc, and sometimes magnesium or a full multivitamin, are the ones people most often find uncomfortable without food. A small amount of food is usually enough to settle things.
Everyone is different — some people take these fine on an empty stomach, while others need a meal. Go by how your own stomach responds.
A comfortable, repeatable routine
The easiest fix is to anchor these to a meal you eat every day, which also makes them easier to remember. Pillog lets you tie a dose to a mealtime, check it off from the notification, and view your month as a card, all on your phone with no account.
If a supplement keeps causing discomfort even with food, that is worth raising with a doctor or pharmacist.