The vast majority of mammals make their own Vitamin C in their liver – removing a few hydrogen atoms from the glucose molecule – to produce this very important substance. Unfortunately we – as well as some primates, guinea pigs and fruit bats – cannot make our own, so we have to eat or drink it. Everybody is in agreement on that, but not on how much.
The RDA – the recommended daily allowance – in the UK is dealt with here and the summary is:
The RDA for Vitamin C ranges from 15–75 mg for children, 75 mg for adult women, 90 mg for adult men, and 85–120 mg for women who are pregnant or breastfeeding. (Note this is a daily total regardless of body weight, not a per kilogram recommendation.)
Here is a link to a video explaining that the maximum that the body can cope with is 200mg/day and that this leads to ideal blood levels.
Now comes the puzzle or conundrum – this is VERY little compared with other mammals.
If we look at animals that make their own on-board Vitamin C