i take d3, k2 and magnesium. eat a wide variety of whole foods. haven't been sick since giving up grains almost 4 years ago.
i'd check for mold in your home or workplace, and change out any air filters too.
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.