Supplements may be used during fasting periods, although some may be better absorbed with food. Supplements that contain calories or sugar are more likely to break your fast.

Does taking multivitamins break a fast?

Since these supplements and multivitamins do not carry added sugar or calories, you can safely take them in your fasting window without having to break your fast.

What breaks a fast intermittent fasting?

Eating anything with calories breaks your fast. Exceptions to this rule would be black coffee, unsweetened and milk-free tea, water, and diet soda (though research says diet soda could actually increase your appetite, which might make it hard to stick to your fast.)