https://www.lifeextension.com/protocols/kidney-urinary/kidney-disease

Also this, from other sources:

Effect of coenzyme Q10 in patients with kidney diseases.

COENZYME Q10 powerfully protects the kidneys

Life Extension sells a number of CoQ10 formulations

Best wishes for your father. He's lucky to have you to help take care of his health; you're cautious approach to "official medical advice" is well founded.

https://www.lifeextension.com/protocols/kidney-urinary/kidney-disease

Also this, from other sources:

Effect of coenzyme Q10 in patients with kidney diseases.

COENZYME Q10 powerfully protects the kidneys

https://www.lifeextension.com/search#q=coq10&t=coveo4A2453FD

Life Extension sells several versions and dose-sizes of CoQ10, including a 100mg version with 10mg of PQQ, something I'd also want to take. I personally take a gram or so of LEF's enhanced, highly absorbable CoQ10. I don't have kidney disease but I also don't want to develop it, among other things.

Best wishes for your father. He's lucky to have you to help take care of his health; you're cautious approach to "official medical advice" is well founded.