You can't play defense against a cold....
I don't think it matters what you do. Once a cold is going around you can't do anything about it.
Every day I eat a banana, yogurt and an apple. I had an app that monitored my water intake and I drink lots. I drink at least one tea with honey every day. Sometimes two and sometimes I throw a green tea in there. I mix my water with low sweeten cranberry juice so there is a little VC in there.
I wash my hands regularly and sometimes use hand sanitizer but am not as crazy using it as I once was. I wear gloves all winter long and never touch door handles.
Still get the head cold. It doesn't matter how careful or health you try to be. You get around a coworker, friend or family member. You might as well sign up for it.