If you can provide the source for this I'll update my thesis. It's been some time since I last researched this, but I seem to recall reading that only humans cannot produce their own vitamin c.
If you type "mammals who cant make vitamin c" in your preferred search engine -mine is Brave-, you will get a plethora of links to explore to your heart's delight concerning the matter.
I read somewhere that bats, guinea pigs and some primates, all mammals, cannot make their own vitamin c either.
If you can provide the source for this I'll update my thesis. It's been some time since I last researched this, but I seem to recall reading that only humans cannot produce their own vitamin c.
If you type "mammals who cant make vitamin c" in your preferred search engine -mine is Brave-, you will get a plethora of links to explore to your heart's delight concerning the matter.
I amended the above. and added, other than humans; guinea pigs, bats and dry-nosed primates have lost their ability to produce vitamin C