I’m pretty sure multivitamins help me in one way - to help prevent me from catching colds and flus easily. I noticed this years ago when my kids were young. I would take one of the chewable kids vitamins daily through autumn and winter. Several winters I did not get sick. I’ve not done it since - every day, one kids vitamin. I switched to adult multis but I think they’re an expensive overload and didn’t seem to help. But chewable kids were too sugary for my teeth. Now they have the xylitol ones. I may try again this season.