I believe most over the counter multi-vitamins can be taken without food. I believe some of the metals like iron and zinc specific pills can cause nausea if taken on an empty stomach. But multivitamins don’t have the heavy levels of those metals that stand alone pills do.Avoid gummy vitamins as these have sugars and can disrupt the effects of fasting.
I take prenatal vitamins.. but if I take any vitamins during the day, it makes me nauseous. So, I take them at bedtime and sleep through it!
I use gummy melatonin at bedtime and it hasn’t affected my fasting weight loss.