lewm,
Dr. John Cannell founded the Vitamin D Council to bring awareness of D's benefits for numerous conditions. Unfortunately for covid, the public has been demoralized into thinking that nothing can be done except take vaccines, steroids, anticoagulants. The reference norms of D25OH at 30-100 ng/ml miss the concept of what is optimal/therapeutic, which is 50-80. When I was sick last year, I also used Ester C 1000 mg every 2 hrs while awake, NAC (N acetyl cysteine) 600 mg 3x/day to increase glutathione levels. I made slow progress, but when I got Quicksilver Scientific's liposomal vit C and glutathione which are almost as good as intravenous forms, I made much more rapid improvement. My patients and I who have done this KNOW that it works, unlike assertions of flawed "controlled" studies in journals, such as the recent JAMA article. I suggest opening a professional account with Quicksilver, which will also give access to webinars by the brilliant chief scientist, Christopher Shade, PhD.
There is a long history of high dose intravenous vit C for many infectious illnesses. Thankfully, Northshore University Hospital in NY started IV vitamin C 1.5 gm every 6 hours early last year for covid. The Vitamin C book by Thomas Levy, MD, JD is useful.
Surviving covid is the first hurdle. Preventing long term sequelae is best accomplished with a holistic, nutritional approach that complements usual medical therapy. I know the medical/dental practice, Whole Body Medicine in Fairfield, Conn which is near Peter. I had my mercury dental fillings removed in 2004 by the founder, Dr. Mark Breiner. His son, Dr. Adam Breiner is a holistic D.O. Dr. David Brady in the practice is a renowned nutritionist.