I take 5,000 IU normally, K2 from eggs every day, 400 mg magnesium 2X / day, and raise the D3 dose to 10,000 IU if I think I’m getting sick (rarely), along with ivermectin and a couple of other anti-virals. This in addition to the remainder of the anti-covid protocol (zinc picolinate, C, NAC, quercetin, etc, etc.).
Another important one: 10 mg melatonin before bed.