Look into K2 MK-7 to go along with the D3, the synergy increases tenfold and is far more beneficial when combined. You also need a far higher level than they currently recommend, especially if melanated.
Most people are so happy to outsource their health (see rush for injections) as opposed to taking preventative steps that ensure their inner terrain is naturally a repellent to pathogenic factors. They're the same kind that would look at a pool of dirty water and say "See, the mosquitos did that" whilst not realizing their ignorance...