Thanks for this thread. I’m on my second multiweek cold since January and I’m ready to be over it. I know I get sick more when my iron is low but it was fine at my last checkup. I’ll try vitamin D and see if that helps.
Another thing to think about: Handwashing. Handwashing is one of the most important ways to prevent transmitting colds and other nasty illnesses.
I used to get a nasty GI tract illness every winter until I started making a point of washing my hands when I got home any time I was out in public, in addition to washing my hands any time I would be eating and such.