Since my son in Special Forces told me he had been advised to take 5000 IU of D, I have added from 2000 to 4000 IU daily. I had been taking K2 but ran out, so better get some more. For over 45 years I have been taking 3 to 6 grams Vitamin C spread thruout the day for my allergies. Dose varied depending on symptoms of clogged nasal passages and sneezing. If I start housecleaning (house dust is one allergy) and my symptoms start, I immediately take 1 or 2 grams and they go away soon. At 81 I am in good health and hope to remain that way.
Sounds like you are on it!