D3, yes I was deficient to the point of illness. I have eventually settled on 2000 every second day, after reading that the bigger dose less often was more effective than daily. The N-Acetyl Cysteine protects the blood oxygen interface of the lungs from invasion. It was difficult to get during the scam de mic as it was found to be extremely effective in conjunction with vit D as protection. It is a natural fermented amino acid that the body produces normally to aid the breaking down and absorption of food and minerals in the gut, which is what I needed it for.I was taking it prior and found out about the lung benefits later. I have auto immune issues. Body builders use it to avoid fat deposition. I get it i bulk and put it in my own capsules. Its a fair bit cheaper that way. John Campbell on the videos on the previous page here has a lot to say about the vit D tie up some time back. Good luck.
