I honestly wouldn’t worry about it because I have read so many studies about the efficacy of vitamin C. I’ve read a ton of what you could call miracle vitamin C healings too, ex: people dieing from abx resistant infections who did high dose lipo or IV C and were cured.
I think you need to alternate your dosage though. I do bowel tolerance twice a week or so, and 2-3 grams on other days. I’ve heard your body can develop ways to break down the C and render it ineffective if you dose to high for too long, so it’s good to alternate it.
I personally know 2 people who have done 20+ grams a day for 20 years and are in good health.
The study they mention isn’t even explained well either, who knows how well it was carried out and what other variables took place.
Vitamin C can sure stir stuff up though and cause herx, so watch out for that. Some people with chronic health issues feel worse after taking very high doses, I think one reason is because of some chronic virus they have that the C starts kicking up and trying to destroy.
But I should also say, it’s up to your own personal decision, you have to weigh the pro’s and con’s for yourself.