Original: Alternative recommendations on intakes Some independent researchers have calculated the amount needed for an adult human to achieve similar blood serum levels as vitamin C synthesising mammals as follows: 400 milligrams per day: the Linus Pauling Institute.
Simplified: Some researchers have calculated the amount needed for an adult human to achieve similar blood serum levels as Vitamin C synthesising mammals as follows: 200 mg per day - Linus Pauling Institute and US National Institutes of Health (NIH) Recommendation.