I hope you're not being serious, but they're not "supplements", they're food. You can easily get them from fruits and vegetables.

While they're not essential in short-term survival, they're essential for long-term health:

https://www.ncbi.nlm.nih.gov/books/NBK559033/

We have enough peer-reviewed studies on this.

I thought we were onto protein now?

it has been for a while, a lot of foods advertise fiber