Breathtaking
Check this.
I am curious where you got this misinformation.
It's not misinformation. I got it from our veterinarian, and from a practical, real world framework, it is true.
Had a cat that got a severe reaction to a rabies vaccination, which resulted in siezures which necessitated making the cat an 'inside' cat. after a few months the cat started having problems like oral, rectal, and ear bleeding. The vet traced the problem to a near total absence of ascorbic acid. I said that I had read that cats could make their own. She laughed, and said that the miniscule amounts that a small percentage of animals may make is negligible. She prescribed grass cubes that were available at pet supply shops. The grass cubes worked within about two weeks.