No one got colds "regularly" during last year's "lockdown and mask" periods, or during the summer. Maybe, if you had a kid in preschool, but they have been closed during those periods as well. There is something unique about your situation you are unaware of or perhaps not telling us.

I'd stop giving out advice to a population that is almost certainly, mostly deficient in Vitamin D. Sure, don't overdo it, but as it is quite hard to, probably affecting a tiny percent of the population, is a lesser concern right now.