since ditching grains 3 years ago, i have not been sick once. no sniffles, no colds, no coughs, when previously they had plagued me all year, all my life.
if you are vitamin d deficient, it's hard to get your reserves back up, just from supps, or even just from the sun. get your levels checked.
is your diet full of variety? you don't need fruit -- i eat berries once or twice per week at most.
you may also want to start using a neti pot regularly. the irrigations keep bugs from getting too comfy in your nasal passages. if you do come down with something, it will clear out the cold much more quickly than cw meds.
As I ate the oysters with their strong taste of the sea and their faint metallic taste that the cold white wine washed away, leaving only the sea taste and the succulent texture, and as I drank their cold liquid from each shell and washed it down with the crisp taste of the wine, I lost the empty feeling and began to be happy and to make plans.
– Ernest Hemingway