Around 5000 species of mammals inhabit the Earth today, and almost all make their own Vitamin C from simple sugar. Your dog doesn’t need orange juice to live a scurvy-free life.
Human ancestors, and most other primates, lost the genetic ability to perform this impressive biochemical feat around 61 million years ago . How did they/we survive?
Short answer – don’t know (yet). It’s accepted that these primate ancestors were insectivores. Insects, in general, do not contain high levels of Vitamin C . But, insects do like hanging around flowers, fruits, and leaves. An insect could be noshing on some C-rich fruit (insects do require Vitamin C for development and reproduction) when the primate ate it. Or the primate could accidentally eat plant material while aiming for the insect.
What about other Vitamin C deficient mammals – Guinea pigs and bats? Guinea pigs… and fruit bats… certainly get plenty of Vitamin C in their diet. What about insect-eating bats? Well, maybe they aren’t as Vitamin C inept as we thought . And, we deficients may be able to survive on less Vitamin C and/or recycle the little we do ingest .
- Lachapelle M.Y. and G. Drouin. 2011. Inactivation dates of the human and guinea pig vitamin C genes. Genetica 139:199–207.
- Kourimska L. and A. Adamkova. 2016. Nutritional and sensory quality of edible insects. NSF Journal. 4:22-26.
- Troadec, M. and J. Kaplan. 2018. Some vertebrates go with the GLO. Cell. 132(6)921-922.